/* ============================================================
   Qiskit Fall Fest 2026 — Design System
   "A Decade of Quantum on Cloud"
   ============================================================ */

/* --- TOKENS ------------------------------------------------- */
:root {
  --bg:            #0D1117;
  --bg-raised:     #171D27;
  --bg-subtle:     #111823;
  --surface:       #1D2633;
  --ink:           #F4F0FF;
  --ink-soft:      #C5BCD6;
  --ink-faint:     #9B91AD;
  --violet-deep:   #B48EE0;
  --violet:        #C4A3E8;
  --violet-mid:    #9B6FD4;
  --violet-light:  #D8C4F0;
  --violet-pale:   #2D2342;
  --violet-line:   #44385C;
  --glow:          #C4A3E8;
  --white:         #FFFFFF;

  --font-display:  'Space Grotesk', sans-serif;
  --font-body:     'IBM Plex Sans', sans-serif;
  --font-mono:     'IBM Plex Mono', monospace;

  --max-width: 1140px;
  --gutter: 24px;
  --radius: 4px;
  --radius-lg: 10px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.24), 0 1px 2px rgba(0,0,0,0.18);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.30), 0 2px 6px rgba(0,0,0,0.22);
  --shadow-lg: 0 12px 48px rgba(0,0,0,0.42), 0 4px 12px rgba(0,0,0,0.24);
}

/* --- RESET -------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  background: var(--bg);
  background-image:
    linear-gradient(rgba(180,142,224,0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(180,142,224,0.045) 1px, transparent 1px),
    radial-gradient(circle at 80% 10%, rgba(124,77,191,0.18), transparent 34rem),
    radial-gradient(circle at 12% 42%, rgba(75,33,112,0.16), transparent 30rem);
  background-size: 36px 36px, 36px 36px, auto, auto;
  background-attachment: fixed;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  color: var(--ink);
}

p { max-width: 64ch; }

a {
  color: var(--violet-deep);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

.mono { font-family: var(--font-mono); }

img { max-width: 100%; display: block; }

:focus-visible {
  outline: 2px solid var(--violet);
  outline-offset: 3px;
  border-radius: 2px;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* --- KEYFRAMES --------------------------------------------- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50%       { transform: scale(1.12); opacity: 0.8; }
}
@keyframes qubitPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(155,111,212,0.5); }
  50%       { box-shadow: 0 0 0 10px rgba(155,111,212,0); }
}
@keyframes shake {
  0%,100% { transform: translate(0,0) rotate(0deg); }
  15%     { transform: translate(-2px,1px) rotate(-0.5deg); }
  30%     { transform: translate(2px,-1px) rotate(0.5deg); }
  45%     { transform: translate(-1px,2px) rotate(-0.3deg); }
  60%     { transform: translate(2px,1px) rotate(0.3deg); }
  75%     { transform: translate(-2px,-1px) rotate(-0.5deg); }
}
@keyframes waveCollapse {
  0%   { transform: scaleY(1); opacity: 1; }
  50%  { transform: scaleY(0.05); opacity: 0.5; }
  100% { transform: scaleY(1); opacity: 1; }
}
@keyframes tunnelThrough {
  0%   { left: -10px; opacity: 0; }
  10%  { opacity: 1; }
  45%  { left: 46%; opacity: 1; }
  55%  { left: 54%; opacity: 0; }
  56%  { opacity: 1; }
  90%  { opacity: 1; }
  100% { left: calc(100% + 10px); opacity: 0; }
}
@keyframes packetTravel {
  0%   { left: 0; opacity: 0; }
  10%  { opacity: 1; }
  90%  { opacity: 1; }
  100% { left: 100%; opacity: 0; }
}
@keyframes glow {
  0%,100% { box-shadow: 0 0 16px rgba(155,111,212,0.3); }
  50%      { box-shadow: 0 0 32px rgba(155,111,212,0.6); }
}
@keyframes registerPulse {
  0%,100% { transform: scale(1); }
  50%      { transform: scale(1.02); }
}
@keyframes particleFloat {
  0%,100% { transform: translateY(0) translateX(0); opacity: 0.7; }
  33%     { transform: translateY(-12px) translateX(6px); opacity: 1; }
  66%     { transform: translateY(6px) translateX(-4px); opacity: 0.8; }
}
@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes spinOnce {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* --- REVEAL (scroll intersection) -------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible {
  opacity: 1;
  transform: none;
}
.reveal[style*="--delay"] { transition-delay: var(--delay, 0s); }

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,17,23,0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--violet-line);
  transition: box-shadow 0.3s ease, background 0.3s ease;
}
.site-header.scrolled {
  box-shadow: var(--shadow-md);
  background: rgba(13,17,23,0.95);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px var(--gutter);
  max-width: var(--max-width);
  margin: 0 auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
  user-select: none;
}
.brand-logo {
  width: 30px;
  height: 30px;
  object-fit: contain;
  flex-shrink: 0;
}
.brand:hover { text-decoration: none; color: var(--violet-deep); }
.site-header .brand-mark {
  width: 38px;
  height: 38px;
}
.brand-mark {
  width: 30px; height: 30px;
  flex-shrink: 0;
  transition: transform 0.4s ease;
}
.brand:hover .brand-mark { transform: rotate(30deg); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}
.nav-links a {
  color: var(--ink-soft);
  font-size: 0.94rem;
  font-weight: 500;
  transition: color 0.25s;
  position: relative;
}
.nav-links a:not(.nav-cta):hover { color: var(--violet-deep); text-decoration: none; }
.nav-links a:not(.nav-cta)::after {
  content: '';
  position: absolute;
  bottom: -3px; left: 0;
  width: 0; height: 1.5px;
  background: var(--violet-deep);
  transition: width 0.25s ease;
}
.nav-links a:not(.nav-cta):hover::after { width: 100%; }

.nav-cta {
  background: var(--violet-deep);
  color: var(--white) !important;
  padding: 9px 20px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  transition: background 0.25s ease, transform 0.2s ease !important;
}
.nav-cta:hover { background: var(--ink) !important; transform: translateY(-1px); text-decoration: none !important; }
.nav-cta::after { display: none !important; }

.nav-toggle {
  display: none;
  background: none; border: none;
  cursor: pointer; padding: 6px;
  flex-direction: column; gap: 5px;
}
.nav-toggle span {
  display: block; width: 22px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 820px) {
  .site-header .brand-mark { width: 36px; height: 36px; }
  .nav-toggle { display: flex; }
  .nav-links {
    position: absolute; top: 100%; left: 0; right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--violet-line);
    flex-direction: column; align-items: flex-start;
    gap: 0; padding: 8px var(--gutter) 20px;
    display: none;
    animation: slideDown 0.2s ease;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; font-size: 1rem; }
  .nav-cta { margin-top: 8px; text-align: center; display: block; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  border-bottom: 1px solid var(--violet-line);
  padding: 80px 0 60px;
}

#wave-canvas {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  opacity: 0.55;
}

.hero-wrap {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  align-items: center;
  position: relative;
  z-index: 2;
}

/* Eyebrow */
.eyebrow-line {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--violet);
  margin-bottom: 20px;
  opacity: 0;
  animation: fadeInUp 0.6s ease 0.1s forwards;
}
.eyebrow-badge {
  background: var(--violet-pale);
  color: var(--violet-deep);
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.78rem;
  border: 1px solid var(--violet-line);
}
.eyebrow-badge img {
  display: block;
  width: 86px;
  height: 24px;
  object-fit: contain;
}
.eyebrow-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

/* Hero h1 */
.hero-copy h1 {
  font-family: 'Cinzel', var(--font-display);
  font-size: clamp(2.6rem, 5vw, 4rem);
  letter-spacing: 0;
  margin-bottom: 20px;
  line-height: 1.1;
  opacity: 0;
  animation: fadeInUp 0.7s ease 0.2s forwards;
}

.gradient-text {
  background: linear-gradient(135deg, var(--violet-deep) 0%, var(--violet-mid) 60%, var(--violet-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--ink-soft);
  max-width: 44ch;
  margin-bottom: 28px;
  opacity: 0;
  animation: fadeInUp 0.7s ease 0.3s forwards;
}

.institution-line {
  display: grid;
  gap: 12px;
  width: min(100%, 520px);
  margin-bottom: 20px;
  padding: 16px 18px;
  border: 2px solid var(--violet-mid);
  border-radius: var(--radius);
  background: rgba(45,35,66,0.52);
  color: var(--violet-light);
}
.organizer-row {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}
.organizer-label {
  min-width: 132px;
  color: var(--violet-mid);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
}
.organizer-row img {
  width: 88px;
  height: 42px;
  object-fit: contain;
  background: rgba(255,255,255,0.92);
  border-radius: 3px;
  padding: 4px;
  flex-shrink: 0;
}
.organizer-home-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}
.organizer-home-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-width: 0;
  text-align: center;
}
.organizer-home-item .organizer-label { min-width: 0; }
.organizer-home-item img {
  width: auto;
  max-width: 100%;
  height: auto;
  max-height: 58px;
  object-fit: contain;
  background: rgba(255,255,255,0.92);
  border-radius: 3px;
  padding: 4px;
}
.organizer-coorganiser-row {
  display: grid;
  gap: 8px;
  padding-top: 12px;
  border-top: 1px solid rgba(155,111,212,0.35);
  text-align: center;
}
.organizer-coorganiser-row .organizer-label { min-width: 0; }
.organizer-coorganiser-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 14px;
}
.organizer-coorganiser-logos img {
  width: auto;
  max-width: 120px;
  height: 65px;
  max-height: 65px;
  object-fit: contain;
  background: rgba(255,255,255,0.92);
  border-radius: 3px;
  padding: 4px;
}
.organizer-lead img { width: 132px; }
.organizer-powered img { width: 108px; }
.organizer-logos {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.organizer-logos span { color: var(--violet-light); }
.hero-quick-links { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 22px; }
.quick-link {
  border: 2px solid var(--violet-mid);
  background: linear-gradient(135deg, rgba(124,77,191,0.22), rgba(45,35,66,0.78));
  color: var(--ink);
  padding: 9px 13px;
  border-radius: var(--radius);
  font-size: 0.82rem;
  font-weight: 600;
  box-shadow: 0 0 14px rgba(155,111,212,0.12);
  transition: border-color 0.2s, color 0.2s, background 0.2s, transform 0.2s, box-shadow 0.2s;
}
.quick-link:hover {
  background: linear-gradient(135deg, rgba(180,142,224,0.38), rgba(75,33,112,0.86));
  border-color: var(--violet-light);
  color: var(--white);
  box-shadow: 0 0 22px rgba(180,142,224,0.28);
  transform: translateY(-2px);
  text-decoration: none;
}

/* Event identity block */
.event-identity {
  display: inline-flex;
  align-items: center;
  background: var(--bg-raised);
  border: 1px solid var(--violet-line);
  border-radius: var(--radius);
  padding: 10px 16px;
  margin-bottom: 24px;
  gap: 12px;
  opacity: 0;
  animation: fadeInUp 0.7s ease 0.35s forwards;
}
.event-name-block { display: flex; flex-direction: column; gap: 2px; }
.event-name-label { font-size: 0.72rem; color: var(--violet-deep); }
.event-name { font-family: var(--font-display); font-weight: 700; font-size: 1.15rem; color: var(--ink); }

/* Hero meta */
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 20px;
  margin-bottom: 32px;
  opacity: 0;
  animation: fadeInUp 0.7s ease 0.4s forwards;
}
.meta-item { display: flex; flex-direction: column; gap: 3px; }
.meta-label { font-size: 0.72rem; color: var(--violet); }
.meta-value { font-size: 0.96rem; font-weight: 500; color: var(--ink); }

/* Hero CTAs */
.hero-ctas {
  display: flex; gap: 12px; flex-wrap: wrap;
  margin-bottom: 20px;
  opacity: 0;
  animation: fadeInUp 0.7s ease 0.5s forwards;
}

/* Feynman trigger */
.feynman-trigger {
  display: inline-block;
  cursor: help;
  color: var(--violet-light);
  margin-top: 12px;
  opacity: 0;
  animation: fadeIn 1s ease 1.5s forwards;
}

/* Bloch sphere */
.hero-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  position: relative;
}
.bloch-container { position: relative; }
#bloch-canvas {
  width: 100%; max-width: 380px;
  aspect-ratio: 1/1; height: auto;
  opacity: 0; animation: fadeIn 0.8s ease 0.6s forwards;
}
.bloch-caption {
  text-align: center;
  font-size: 1rem;
  font-weight: 500;
  color: var(--ink-faint);
  margin-top: 8px;
  margin-bottom: 18px;
  line-height: 1.4;
  opacity: 0; animation: fadeIn 0.8s ease 0.9s forwards;
}

/* Qubit particles */
.qubit-particle {
  position: absolute;
  width: 36px; height: 36px;
  cursor: pointer;
  z-index: 10;
}
.qubit-a { top: 28px; right: var(--gutter); }
.qubit-b { position: absolute; bottom: 40px; left: 40px; }

.qubit-inner {
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--violet-mid);
  position: absolute; top: 50%; left: 50%;
  transform: translate(-50%,-50%);
  animation: qubitPulse 2s ease infinite;
  transition: background 0.3s, transform 0.3s;
}
.qubit-particle:hover .qubit-inner,
.qubit-particle:focus .qubit-inner { background: var(--violet-deep); transform: translate(-50%,-50%) scale(1.4); }
.qubit-particle.entangled .qubit-inner { background: var(--violet-deep); animation: pulse 0.4s ease 3; }

.qubit-label {
  font-family: var(--font-mono); font-size: 0.68rem; color: var(--violet);
  text-align: center; margin-top: 26px; white-space: nowrap;
}

/* Scroll cue */
.scroll-cue {
  position: absolute; bottom: 28px; left: 50%;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  color: var(--ink-faint); font-size: 0.72rem;
  font-family: var(--font-mono);
  animation: fadeIn 1s ease 1.2s both;
  pointer-events: none;
}
.scroll-arrow {
  width: 1px; height: 28px;
  background: linear-gradient(to bottom, var(--violet-light), transparent);
  animation: fadeInUp 1.5s ease 1.2s infinite;
}

/* Collapse toast */
.collapse-toast {
  position: fixed; bottom: 32px; left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #4B2170; color: var(--white);
  border: 1px solid var(--violet-light);
  box-shadow: 0 8px 28px rgba(0,0,0,0.36);
  padding: 14px 26px; border-radius: 8px;
  font-size: 0.9rem; z-index: 999;
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
}
.collapse-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* Hero responsive */
@media (max-width: 900px) {
  .hero-wrap { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { order: -1; }
  #bloch-canvas { max-width: 260px; }
  odinger-box { transform: scale(0.85); }
}

/* ============================================================
   SCHRÖDINGER'S BOX
   ============================================================ */
.schrodinger-box {
  position: relative;
  margin-top: 70px;
  width: 220px;
  height: 210px;
  cursor: pointer;
  user-select: none;
  perspective: 600px;
  transition: transform 0.2s ease;
}
.schrodinger-box:hover { transform: translateY(-4px); }
.schrodinger-box:hover .box-body { animation: shake 0.5s ease; }

/* Box faces — CSS isometric box */
.box-body {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  transform: rotateX(-10deg) rotateY(-20deg);
}
.box-face {
  position: absolute;
  border: 1.5px solid var(--violet-mid);
}
.box-face.front {
  width: 150px; height: 165px;
  background: linear-gradient(145deg, #2D2342 0%, #141A25 100%);
  top: 0; left: 0;
  border-radius: 2px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-sm);
}
.box-face.top {
  width: 150px; height: 40px;
  background: linear-gradient(to right, #211832, #3A2856);
  top: -38px; left: 5px;
  transform: rotateX(55deg);
  border-top: none;
}
.box-face.side {
  width: 48px; height: 165px;
  background: linear-gradient(to bottom, #3A2856 0%, #171D27 100%);
  top: 0; left: 148px;
  transform: rotateY(-70deg) translateX(-4px);
}

/* Box label */
.box-label { padding: 16px; }
.box-title {
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 500;
  color: #F4F0FF; letter-spacing: 0.05em; margin-bottom: 4px;
}
.box-subtitle { font-family: var(--font-mono); font-size: 0.64rem; color: var(--violet-light); margin-bottom: 10px; }
.box-warning {
  display: flex; align-items: center; gap: 4px;
  font-family: var(--font-mono); font-size: 0.64rem; color: var(--violet-light);
  border: 1px solid var(--violet-mid); padding: 5px 8px; border-radius: 2px;
  width: fit-content;
}

/* State badge */
.box-state-badge {
  position: absolute; bottom: -36px; left: 0; right: 0;
  display: flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-soft);
}
.state-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--violet-mid);
  animation: pulse 1.8s ease infinite;
}
.schrodinger-box[data-state="observed"] .state-dot { background: var(--violet-deep); animation: none; }
.schrodinger-box[data-state="observed"] .state-dot { background: #2e9e57; }

/* Tooltip */
.box-tooltip {
  position: absolute; top: -52px; left: 50%;
  transform: translateX(-50%);
  background: var(--violet-deep); color: var(--white);
  border: 1px solid var(--violet-light);
  box-shadow: 0 8px 24px rgba(0,0,0,0.32);
  font-family: var(--font-mono); font-size: 0.78rem;
  padding: 9px 14px; border-radius: 5px; white-space: nowrap;
  opacity: 0; pointer-events: none;
  transition: opacity 0.2s ease;
}
.box-tooltip::after {
  content: ''; position: absolute; top: 100%; left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent; border-top-color: var(--violet-light);
}
.schrodinger-box:hover .box-tooltip { opacity: 1; }

/* Cat reveal */
.box-cat {
  position: absolute; inset: 8px 8px 38px 8px;
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none;
  transition: opacity 0.35s ease;
}
.box-cat svg { width: 90%; height: 90%; }
.schrodinger-box[data-state="observed"] .box-cat { opacity: 1; }
.schrodinger-box[data-state="observed"] .box-face.front { background: linear-gradient(145deg, #432B63, #1A202E); }

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius);
  font-weight: 500; font-size: 0.97rem;
  font-family: var(--font-body);
  cursor: pointer; border: 1px solid transparent;
  transition: all 0.25s ease;
  position: relative; overflow: hidden;
  text-decoration: none;
}
.btn::after {
  content: ''; position: absolute; inset: 0;
  background: rgba(255,255,255,0.08);
  opacity: 0; transition: opacity 0.25s;
}
.btn:hover::after { opacity: 1; }
.btn:hover { transform: translateY(-2px); text-decoration: none; }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--violet-deep); color: var(--white);
  box-shadow: 0 2px 12px rgba(75,33,112,0.25);
}
.btn-primary:hover { background: var(--ink); box-shadow: 0 4px 20px rgba(75,33,112,0.35); color: var(--white); }

.btn-secondary {
  background: transparent; color: var(--ink);
  border-color: var(--violet-line);
}
.btn-secondary:hover { border-color: var(--violet-deep); color: var(--violet-deep); }

/* ============================================================
   SECTIONS — scaffold
   ============================================================ */
main {
  display: flex;
  flex-direction: column;
}
#home { order: 1; }
#about { order: 2; }
#haqthon { order: 3; }
#schedule { order: 4; }
#speakers { order: 5; }
#collaboration { order: 6; }
#arena { order: 7; }
#circuit { order: 7; }
#organisers { order: 8; }
#social { order: 9; }
#register { order: 10; }
#faq { order: 11; }

.section {
  padding: 88px 0;
  border-bottom: 1px solid var(--violet-line);
}
.section-raised { background: var(--bg-subtle); }
.haqthon-section { background: linear-gradient(135deg, rgba(45,35,66,0.82), rgba(17,24,35,0.92)); }
.haqthon-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 64px; align-items: start; }
.haqthon-copy p { max-width: 42ch; color: var(--ink-soft); margin-bottom: 28px; font-size: 1.08rem; }
.haqthon-points { display: grid; gap: 14px; }
.haqthon-points > div { display: grid; grid-template-columns: 36px 1fr; column-gap: 14px; border-top: 1px solid var(--violet-line); padding-top: 14px; }
.haqthon-points span { color: var(--violet); font-size: 0.76rem; }
.haqthon-points strong { font-family: var(--font-display); }
.haqthon-points p { grid-column: 2; color: var(--ink-soft); font-size: 0.88rem; margin-top: 4px; }
.arena-question {
  margin-bottom: 8px;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
}
.section:last-of-type { border-bottom: none; }

.section-head {
  margin-bottom: 48px;
}
.section-kicker {
  font-family: 'Cinzel', var(--font-display);
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  font-weight: 600;
  line-height: 1.15;
  color: var(--violet-light);
  margin-bottom: 14px;
  letter-spacing: 0;
}
.section-head h2 {
  max-width: 30ch;
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  line-height: 1.2;
  letter-spacing: 0;
}
.section-intro { color: var(--ink-soft); margin-bottom: 36px; font-size: 1.05rem; }

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 64px;
  align-items: start;
}
.about-body p { color: var(--ink-soft); margin-bottom: 1.1em; }
.about-body p:last-child { margin-bottom: 0; }
.about-cloud-description {
  max-width: 42ch;
  margin-top: 28px;
  color: var(--violet-light);
  font-family: var(--font-display);
  font-size: 1.05rem;
}
.about-timeline {
  margin-top: 64px;
  padding-top: 36px;
  border-top: 1px solid var(--violet-line);
}
.about-timeline h3 {
  max-width: 30ch;
  margin-bottom: 32px;
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  line-height: 1.2;
  font-weight: 600;
}
.about-timeline > .section-kicker {
  max-width: 30ch;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  line-height: 1.2;
  font-weight: 600;
}
.about-timeline-list {
  display: grid;
  gap: 0;
  border-left: 1px solid var(--violet-line);
}
.about-timeline-item {
  position: relative;
  padding: 0 0 28px 24px;
  margin-left: 14px;
}
.about-timeline-item::before {
  content: '';
  position: absolute;
  top: 4px;
  left: -19px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--violet-light);
  border-radius: 50%;
  background: var(--bg);
}
.about-timeline-meta {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 6px;
  color: var(--violet);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}
.about-timeline-meta b { color: var(--ink-faint); font-weight: 400; }
.about-timeline-item h4 {
  margin-bottom: 6px;
  font-size: 1.05rem;
}
.about-timeline-item p {
  max-width: 72ch;
  color: var(--ink-soft);
  font-size: 0.9rem;
  margin: 0;
}

.track-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.track-card {
  padding: 20px;
  border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg);
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--surface);
  transition: box-shadow 0.25s, border-color 0.25s, transform 0.25s;
}
.track-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--violet-light);
  transform: translateY(-3px);
}
.track-card-icon {
  width: 40px; height: 40px; border-radius: 8px;
  background: var(--bg-raised);
  display: flex; align-items: center; justify-content: center;
  color: var(--violet); flex-shrink: 0;
}
.track-card h3 { font-size: 1rem; margin-bottom: 6px; }
.track-card p { font-size: 0.88rem; color: var(--ink-soft); margin: 0; }

@media (max-width: 900px) { .about-grid { grid-template-columns: 1fr; gap: 40px; } }
@media (max-width: 560px) { .track-cards { grid-template-columns: 1fr; } }

/* ============================================================
   QUBIT EXPLAINER
   ============================================================ */
.bit-qubit-demo {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 32px; align-items: center;
  margin-bottom: 48px;
}

.bit-card {
  background: var(--surface);
  border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}
.qubit-card { border-color: var(--violet-light); box-shadow: 0 0 0 1px var(--violet-line), var(--shadow-md); }

.bit-label { font-size: 0.72rem; letter-spacing: 0.1em; color: var(--violet); margin-bottom: 16px; }
.bit-display {
  display: flex; gap: 8px; margin-bottom: 16px;
}
.bit-option {
  width: 52px; height: 52px;
  border: 2px solid var(--violet-line);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-size: 1.4rem; font-weight: 600;
  color: var(--ink-faint);
  transition: all 0.3s ease;
}
.bit-option.active {
  border-color: var(--violet-deep);
  color: var(--violet-deep);
  background: var(--bg-raised);
  box-shadow: 0 0 0 3px rgba(75,33,112,0.1);
}
.bit-desc { font-size: 0.9rem; color: var(--ink-soft); margin-bottom: 16px; }

.bit-flip-btn, .qubit-measure-btn {
  background: var(--bg-raised); border: 1px solid var(--violet-line);
  padding: 8px 16px; border-radius: var(--radius);
  font-size: 0.86rem; font-family: var(--font-body);
  cursor: pointer; color: var(--ink);
  transition: all 0.2s ease;
}
.bit-flip-btn:hover, .qubit-measure-btn:hover { border-color: var(--violet); color: var(--violet-deep); }
.qubit-measure-btn { background: var(--violet-deep); color: var(--white); border-color: var(--violet-deep); }
.qubit-measure-btn:hover { background: var(--ink); border-color: var(--ink); color: var(--white); }

.qubit-display { margin-bottom: 16px; }
.qubit-state-eq {
  font-family: var(--font-mono); font-size: 1.1rem;
  color: var(--violet-deep); margin-bottom: 16px;
  display: flex; align-items: center; gap: 2px; flex-wrap: wrap;
}
.q-alpha, .q-beta { color: var(--violet-mid); }
.q-ket { color: var(--violet-deep); }
.q-plus { color: var(--ink-soft); }

.qubit-prob-bars { display: flex; flex-direction: column; gap: 10px; }
.prob-bar-wrap { display: flex; align-items: center; gap: 10px; }
.prob-label { font-size: 0.78rem; color: var(--ink-soft); width: 28px; }
.prob-track { flex: 1; height: 8px; background: var(--violet-line); border-radius: 4px; overflow: hidden; }
.prob-fill { height: 100%; background: linear-gradient(to right, var(--violet-deep), var(--violet-mid)); border-radius: 4px; transition: width 0.5s ease; }
.prob-pct { font-size: 0.78rem; color: var(--violet); width: 36px; text-align: right; }

/* Transition arrow */
.transition-arrow {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  color: var(--violet-light);
}
.arrow-line {
  width: 1px; height: 40px;
  background: linear-gradient(to bottom, transparent, var(--violet-light), transparent);
}
.arrow-label { font-size: 0.62rem; color: var(--violet-light); writing-mode: vertical-rl; }

/* Measurement Easter Egg */
.measure-egg {
  background: var(--bg-raised);
  border: 1px dashed var(--violet-line);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  display: flex; align-items: center; gap: 24px;
  margin-bottom: 48px; cursor: pointer;
  transition: border-color 0.3s, background 0.3s;
}
.measure-egg:hover { border-color: var(--violet-mid); }
.measure-egg-inner { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.dont-measure-label { font-size: 0.8rem; color: var(--violet); }
.measure-eq { font-size: 1rem; color: var(--ink); }
.measure-hint { font-size: 0.72rem; color: var(--ink-faint); }

.qubit-insight-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.insight-card {
  padding: 28px;
  border: 1px solid var(--violet-line); border-radius: var(--radius-lg);
  background: var(--surface); text-align: center;
  transition: box-shadow 0.25s, transform 0.25s;
}
.insight-card:hover { box-shadow: var(--shadow-md); transform: translateY(-4px); }
.insight-icon { font-size: 1.8rem; color: var(--violet); margin-bottom: 14px; }
.insight-card h3 { font-size: 1.05rem; margin-bottom: 10px; }
.insight-card p { font-size: 0.9rem; color: var(--ink-soft); margin: 0; }

@media (max-width: 900px) { .bit-qubit-demo { grid-template-columns: 1fr; } .transition-arrow { display: none; } }
@media (max-width: 700px) { .qubit-insight-grid { grid-template-columns: 1fr; } }

/* ============================================================
   CLOUD + QUANTUM FLOW
   ============================================================ */
.cloud-flow-vis {
  display: flex; align-items: center; justify-content: center;
  gap: 0; flex-wrap: wrap; margin-bottom: 28px;
  padding: 48px 32px;
  background: var(--surface); border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg); overflow: hidden;
}
.flow-node {
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  padding: 20px; min-width: 110px;
  transition: transform 0.3s ease;
}
.flow-node:hover { transform: translateY(-4px); }
.flow-icon {
  width: 64px; height: 64px; border-radius: 12px;
  background: var(--bg-raised); border: 1px solid var(--violet-line);
  display: flex; align-items: center; justify-content: center;
  color: var(--violet);
}
.flow-result-icon { border-color: var(--violet-light); background: var(--violet-pale); color: var(--violet-deep); }
.flow-label { font-size: 0.82rem; font-weight: 600; color: var(--ink); }
.flow-sub { font-size: 0.72rem; color: var(--ink-faint); text-align: center; }

.flow-connector {
  position: relative; display: flex; align-items: center;
  color: var(--violet-line); width: 60px; flex-shrink: 0;
}
.flow-packet {
  position: absolute; width: 8px; height: 8px; border-radius: 50%;
  background: var(--violet-mid); top: 50%; transform: translateY(-50%);
  opacity: 0;
}
.cloud-flow-caption { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.cloud-caption-text { font-size: 0.86rem; color: var(--ink-soft); }

/* ============================================================
   QUANTUM CIRCUIT PLAYGROUND
   ============================================================ */
.circuit-playground {
  background: var(--surface);
  border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 36px;
}
.circuit-header { padding: 16px 20px; border-bottom: 1px solid var(--violet-line); background: var(--bg-subtle); }
.gate-palette { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.gate-btn {
  width: 40px; height: 40px; border-radius: 6px;
  border: 1.5px solid var(--violet-line);
  background: var(--surface); color: var(--violet-deep);
  font-family: var(--font-mono); font-size: 0.9rem; font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}
.gate-btn:hover { border-color: var(--violet); background: var(--bg-raised); transform: scale(1.08); }
.gate-btn.selected { border-color: var(--violet-deep); background: var(--violet-deep); color: var(--white); }
.gate-measure { border-color: var(--violet-deep); color: var(--violet-deep); }
.circuit-reset-btn {
  margin-left: auto; font-size: 0.8rem; padding: 6px 14px;
  border: 1px solid var(--violet-line); border-radius: var(--radius);
  background: transparent; color: var(--ink-soft); cursor: pointer;
  font-family: var(--font-body);
  transition: border-color 0.2s, color 0.2s;
}
.circuit-reset-btn:hover { border-color: var(--violet); color: var(--violet); }

.circuit-diagram { padding: 24px 20px; display: flex; flex-direction: column; gap: 20px; }
.circuit-wire {
  display: flex; align-items: center; gap: 0; position: relative; height: 48px;
}
.wire-label { font-family: var(--font-mono); font-size: 0.8rem; color: var(--violet); width: 56px; flex-shrink: 0; }
.wire-line {
  flex: 1; height: 1.5px;
  background: linear-gradient(to right, var(--violet-line), var(--violet-pale));
  position: absolute; left: 56px; right: 0; top: 50%; transform: translateY(-50%);
}
.wire-gates { position: absolute; left: 60px; display: flex; gap: 8px; align-items: center; }
.gate-on-wire {
  width: 36px; height: 36px; border-radius: 4px;
  border: 1.5px solid var(--violet);
  background: var(--white); color: var(--violet-deep);
  font-family: var(--font-mono); font-size: 0.82rem; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
  animation: scaleIn 0.2s ease;
  cursor: default; flex-shrink: 0;
}
.gate-on-wire.gate-H { border-color: var(--violet-mid); background: var(--violet-pale); }
.gate-on-wire.gate-X { border-color: #5a9e6f; background: #f0faf4; color: #2e7d50; }
.gate-on-wire.gate-Z { border-color: #9e7a5a; background: #fdf6f0; color: #7d4e2e; }
.gate-on-wire.gate-M { border-color: var(--violet-deep); background: var(--violet-deep); color: var(--white); }
.gate-on-wire.gate-cnot-ctrl { border-radius: 50%; width: 12px; height: 12px; background: var(--violet-deep); border: none; }
.gate-on-wire.gate-cnot-target { border-radius: 50%; position: relative; }
.gate-on-wire.gate-cnot-target::before {
  content: ''; position: absolute; width: 1px; height: 200%;
  background: var(--violet); top: 50%; left: 50%; transform: translate(-50%,-50%);
}

@keyframes scaleIn { from { opacity:0; transform:scale(0.7); } to { opacity:1; transform:scale(1); } }

.circuit-result {
  padding: 14px 20px; border-top: 1px solid var(--violet-line);
  background: var(--bg-subtle); display: flex; align-items: center; gap: 12px;
}
.circuit-result-label { font-size: 0.78rem; color: var(--violet); }
.circuit-state-display { font-family: var(--font-mono); font-size: 1.1rem; color: var(--ink); font-weight: 600; }

/* Heisenberg egg */
.heisenberg-egg {
  display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
  background: var(--bg-raised); border: 1px dashed var(--violet-line);
  border-radius: var(--radius-lg); padding: 16px 22px; cursor: default;
}
.heisenberg-values { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.heisenberg-item { font-size: 0.86rem; color: var(--ink-soft); }
.heisenberg-item strong { color: var(--violet-deep); }
.heisenberg-sep { color: var(--violet-line); }
.heisenberg-hint { font-size: 0.72rem; color: var(--ink-faint); margin-left: auto; }
.heisenberg-egg.uncertain .heisenberg-item:nth-child(1) strong { filter: blur(2px); transition: filter 0.3s; }
.heisenberg-egg.uncertain .heisenberg-item:nth-child(3) strong { filter: none; color: var(--violet-mid); }

/* ============================================================
   TIMELINE
   ============================================================ */
.timeline-scroll-container {
  width: 100%; overflow-x: auto; overflow-y: visible;
  padding: 48px 0;
  scrollbar-width: thin; scrollbar-color: var(--violet-line) transparent;
  -webkit-overflow-scrolling: touch;
}
.timeline-scroll-container::-webkit-scrollbar { height: 4px; }
.timeline-scroll-container::-webkit-scrollbar-track { background: transparent; }
.timeline-scroll-container::-webkit-scrollbar-thumb { background: var(--violet-line); border-radius: 2px; }

.timeline-track {
  display: flex; gap: 0;
  padding: 0 var(--gutter);
  min-width: max-content;
  position: relative;
}
.timeline-track::before {
  content: '';
  position: absolute; top: 38px; left: var(--gutter); right: var(--gutter);
  height: 1.5px;
  background: linear-gradient(to right, var(--violet-pale), var(--violet-light), var(--violet-pale));
}

.timeline-item {
  position: relative; flex-shrink: 0;
  width: 240px; padding: 0 20px 0 0;
  cursor: pointer;
}
.tl-dot {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--surface); border: 2.5px solid var(--violet-light);
  margin-bottom: 20px; position: relative; z-index: 1;
  transition: border-color 0.3s, transform 0.3s;
}
.timeline-item:hover .tl-dot,
.timeline-item.active .tl-dot {
  border-color: var(--violet-deep);
  transform: scale(1.3);
  background: var(--violet-pale);
}
.timeline-item.active .tl-dot { background: var(--violet-deep); }

.tl-card {
  background: var(--surface); border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg); padding: 18px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, border-color 0.3s, transform 0.3s;
}
.timeline-item:hover .tl-card,
.timeline-item.active .tl-card {
  box-shadow: var(--shadow-md); border-color: var(--violet-light);
  transform: translateY(-4px);
}
.tl-year {
  font-family: var(--font-mono); font-size: 0.72rem;
  color: var(--violet); margin-bottom: 6px;
  display: flex; align-items: center; gap: 6px;
}
.tl-tag {
  background: var(--violet-pale); color: var(--violet-deep);
  font-size: 0.62rem; padding: 2px 8px; border-radius: 20px; margin-left: auto;
}
.tl-card h3 { font-size: 0.96rem; margin-bottom: 8px; }
.tl-card p { font-size: 0.82rem; color: var(--ink-soft); margin: 0; line-height: 1.5; }

.timeline-nav {
  display: flex; align-items: center; gap: 16px; justify-content: center; margin-top: 20px;
}
.timeline-nav-btn {
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid var(--violet-line);
  background: var(--surface); color: var(--ink);
  cursor: pointer; font-size: 1.1rem;
  transition: all 0.2s ease; display: flex; align-items: center; justify-content: center;
}
.timeline-nav-btn:hover { border-color: var(--violet); color: var(--violet-deep); background: var(--bg-raised); }
.timeline-progress {
  display: flex; gap: 6px;
}
.tl-prog-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--violet-line); transition: background 0.3s;
}
.tl-prog-dot.active { background: var(--violet-deep); }

/* ============================================================
   SCHEDULE
   ============================================================ */
.day-tabs {
  display: flex; gap: 0; border-bottom: 1px solid var(--violet-line);
  margin-bottom: 0; flex-wrap: wrap;
}
.day-tab {
  background: none; border: none; border-bottom: 2.5px solid transparent;
  position: relative; top: 1px;
  padding: 12px 24px; cursor: pointer;
  font-family: var(--font-mono); font-size: 0.86rem; color: var(--ink-soft);
  transition: color 0.2s, border-color 0.2s;
}
.day-tab[aria-selected="true"] { color: var(--violet-deep); border-bottom-color: var(--violet-deep); }
.day-tab:hover { color: var(--violet-deep); }

.filter-tabs {
  display: flex; gap: 8px; align-items: center;
  padding: 16px 0; flex-wrap: wrap;
}
.filter-label { font-size: 0.78rem; color: var(--ink-faint); margin-right: 4px; }
.filter-btn {
  background: transparent; border: 1px solid var(--violet-line);
  padding: 5px 14px; border-radius: 20px;
  font-size: 0.82rem; color: var(--ink-soft);
  cursor: pointer; font-family: var(--font-body);
  transition: all 0.2s ease;
}
.filter-btn:hover { border-color: var(--violet); color: var(--violet-deep); }
.filter-btn.active {
  background: var(--violet-deep); border-color: var(--violet-deep);
  color: var(--white);
}

.session-list { padding: 8px 0 0; display: none; }
.session-list.active { display: block; }

.schedule-day-details {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
  padding: 16px 18px;
  margin-bottom: 10px;
  border: 1px solid var(--violet-line);
  border-radius: var(--radius);
  background: var(--bg-subtle);
  color: var(--ink-soft);
  font-size: 0.9rem;
}
.schedule-day-details span { display: flex; flex-direction: column; gap: 2px; }
.schedule-day-details strong {
  color: var(--violet);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.schedule-tracks {
  margin: 12px 0 8px;
  padding: 16px 18px;
  border-left: 2px solid var(--violet-mid);
  background: rgba(45,35,66,0.24);
}
.schedule-tracks-title {
  margin-bottom: 8px;
  color: var(--violet-light);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.schedule-tracks ol { margin: 0; padding-left: 22px; color: var(--ink-soft); font-size: 0.9rem; }
.schedule-tracks li { padding: 2px 0; }

.session-item {
  display: grid; grid-template-columns: 100px 1fr;
  gap: 24px; padding: 22px 0;
  border-bottom: 1px solid var(--violet-line);
  transition: all 0.25s ease;
}
.session-item:last-child { border-bottom: none; }
.session-item:hover { padding-left: 10px; border-left: 3px solid var(--violet-light); }
.session-item[data-type="break"] { opacity: 0.55; }
.session-item.hidden { display: none; }

.session-time { font-family: var(--font-mono); color: var(--violet-deep); font-size: 0.86rem; padding-top: 2px; }
.session-date-label { display: block; margin-bottom: 5px; color: var(--ink-soft); font-size: 0.7rem; }
.session-time-end { display: block; font-size: 0.72rem; color: var(--ink-faint); margin-top: 2px; }
.session-title { font-family: var(--font-display); font-size: 1.05rem; font-weight: 600; margin-bottom: 4px; }
.session-speaker { font-size: 0.82rem; color: var(--violet); font-family: var(--font-mono); margin-bottom: 6px; }
.session-desc { font-size: 0.88rem; color: var(--ink-soft); margin: 0; }
.session-tag {
  display: inline-flex; align-items: center;
  font-family: var(--font-mono); font-size: 0.68rem;
  color: var(--violet-deep); background: var(--bg-raised);
  border: 1px solid var(--violet-line);
  padding: 2px 8px; border-radius: 2px; margin-bottom: 8px;
}
.session-tag.tag-workshop { color: #1e6e3c; background: #f0faf4; border-color: #a8d8bc; }
.session-tag.tag-panel { color: #7a5a1e; background: #fdf8ed; border-color: #d8c08c; }
.session-tag.tag-hands-on { color: #1e4a7a; background: #edf4fd; border-color: #8cb8d8; }
.session-tag.tag-break { color: var(--ink-faint); background: transparent; border-color: transparent; }
.session-tag.tag-competition { color: #8a4a1e; background: #fff4ea; border-color: #e2b58e; }
.session-tag.tag-coding { color: #68418c; background: #f3edfa; border-color: #c4a3e8; }
.session-tag.tag-ceremony { color: #7a5a1e; background: #fdf8ed; border-color: #d8c08c; }

@media (max-width: 640px) {
  .session-item { grid-template-columns: 1fr; gap: 6px; }
}

/* ============================================================
   SPEAKERS
   ============================================================ */
.speaker-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 32px; margin-top: 8px; position: relative;
}
.speaker-card {
  position: relative; overflow: hidden;
  border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg); background: var(--surface);
  transition: box-shadow 0.3s, transform 0.3s, border-color 0.3s;
}
.speaker-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-6px); border-color: var(--violet-light); }

.speaker-card-inner { padding: 24px; }
.speaker-photo {
  width: 104px; height: 104px; border-radius: 50%;
  background: var(--bg-raised); border: 2px solid var(--violet-line);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px; overflow: hidden; color: var(--violet);
  flex-shrink: 0;
}
.speaker-photo svg { width: 58px; height: 58px; }
.speaker-photo img { width: 100%; height: 100%; object-fit: cover; }

.speaker-tag {
  font-family: var(--font-mono); font-size: 0.65rem;
  color: var(--violet); background: var(--violet-pale);
  padding: 2px 8px; border-radius: 20px; display: inline-block; margin-bottom: 8px;
}
.speaker-name { font-size: 1.05rem; font-weight: 700; margin-bottom: 2px; }
.speaker-role { font-size: 0.82rem; color: var(--violet-deep); margin-bottom: 2px; }
.speaker-org { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); margin-bottom: 12px; }
.speaker-bio { font-size: 0.86rem; color: var(--ink-soft); line-height: 1.55; margin: 0; }

.speaker-hover-detail {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, var(--violet-deep) 0%, #3a1a58 100%);
  color: var(--white); padding: 24px;
  display: flex; flex-direction: column; justify-content: center;
  opacity: 0; transition: opacity 0.3s ease;
  pointer-events: none;
}
.speaker-card:hover .speaker-hover-detail { opacity: 1; pointer-events: auto; }
.hover-qstate { font-family: var(--font-mono); font-size: 0.72rem; opacity: 0.6; margin-bottom: 8px; }
.hover-name { font-family: var(--font-display); font-size: 1.1rem; font-weight: 700; margin-bottom: 4px; color: var(--white); }
.hover-bio { font-size: 0.86rem; opacity: 0.88; line-height: 1.55; margin-bottom: 16px; }
.hover-link {
  font-family: var(--font-mono); font-size: 0.78rem;
  color: var(--violet-light); text-decoration: underline;
  pointer-events: auto;
}
.hover-link:hover { color: var(--white); }

@media (max-width: 900px) { .speaker-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .speaker-grid { grid-template-columns: 1fr; } }

/* ============================================================
   VENUE
   ============================================================ */
.venue-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.venue-info { display: flex; flex-direction: column; gap: 20px; }
.venue-detail {}
.venue-detail-label { font-family: var(--font-mono); font-size: 0.72rem; color: var(--violet); margin-bottom: 4px; }
.venue-detail-value { font-size: 1rem; color: var(--ink); }

.venue-map-placeholder {
  background: var(--bg-raised); border: 1px dashed var(--violet-line);
  border-radius: var(--radius-lg); overflow: hidden;
}
.map-inner {
  height: 100%; min-height: 200px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 12px; color: var(--ink-faint); padding: 32px; text-align: center;
}
.map-inner svg { color: var(--violet-light); }
.map-inner p { font-size: 0.86rem; margin: 0; color: var(--ink-faint); }
.map-inner p.mono { font-size: 0.9rem; color: var(--ink-soft); }

@media (max-width: 700px) { .venue-grid { grid-template-columns: 1fr; } }

/* ============================================================
   PARTNERS
   ============================================================ */
.partners-strip { display: grid; gap: 18px; }
.partners-row { display: grid; gap: 16px; }
.partners-row-primary { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.partners-row-secondary { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.partner-slot {
  display: flex; align-items: center; gap: 10px;
  border: 1px solid var(--violet-line); border-radius: var(--radius-lg);
  padding: 18px 24px; font-family: var(--font-mono); font-size: 1rem; color: var(--ink-soft);
  background: var(--surface);
  transition: border-color 0.25s, box-shadow 0.25s;
}
.partner-slot:hover { border-color: var(--violet-light); box-shadow: var(--shadow-sm); }
.partner-slot svg { color: var(--violet); flex-shrink: 0; }
.partner-link { min-width: 0; color: var(--ink-soft); }
.partner-link:hover { text-decoration: none; color: var(--ink); }
.partner-link img { width: 120px; height: 96px; object-fit: contain; flex-shrink: 0; background: var(--white); border-radius: 4px; padding: 5px; }
.partners-row-primary .partner-link img { width: 180px; height: 105px; }
.partner-slot-add { border-style: dashed; color: var(--ink-faint); }
.organisers-details-placeholder {
  min-height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px dashed var(--violet-mid);
  border-radius: var(--radius-lg);
  color: var(--ink-faint);
  background: rgba(45,35,66,0.28);
}
.organisers-details {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) minmax(280px, 1.3fr) minmax(280px, 1.3fr);
  gap: 32px;
  padding: 28px;
  border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg);
  background: var(--surface);
}
.organiser-group { min-width: 0; }
.organiser-group-label {
  margin-bottom: 12px;
  color: var(--violet);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.organiser-lead-name {
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
}
.organiser-detail {
  margin-top: 6px;
  color: var(--ink-soft);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}
.organiser-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 28px;
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--ink-soft);
  font-size: 0.98rem;
}
.organiser-list li {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--violet-line);
}
.organiser-list li > span { white-space: nowrap; }
.organiser-list small {
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  line-height: 1.45;
}
.team-member-group + .team-member-group { margin-top: 20px; }
.team-member-group > strong {
  display: block;
  margin-bottom: 10px;
  color: var(--ink);
  font-size: 0.92rem;
}

@media (max-width: 1100px) {
  .organisers-details { grid-template-columns: 1fr 1fr; }
  .team-member-group { grid-column: 1 / -1; }
  .team-member-group .organiser-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 700px) {
  .organizer-row { align-items: flex-start; flex-wrap: wrap; }
  .organizer-label { width: 100%; }
  .organizer-logos { width: 100%; }
  .organizer-home-row { gap: 8px; }
  .organizer-home-item img { max-height: 48px; }
  .organizer-coorganiser-logos img { max-width: 78px; max-height: 42px; }
  .organisers-details { grid-template-columns: 1fr; gap: 24px; padding: 20px; }
  .team-member-group { grid-column: auto; }
  .team-member-group .organiser-list { grid-template-columns: 1fr; }
  .organiser-list { grid-template-columns: 1fr; gap: 8px; }
  .partners-row-primary { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .partners-row-primary .partner-slot { padding: 10px; gap: 6px; font-size: 0.72rem; }
  .partners-row-primary .partner-link img { width: 64px; height: 54px; }
  .partners-row-secondary .partner-slot { font-size: 0.9rem; }
  .partners-row-secondary { grid-template-columns: 1fr; }
}

.social-wrap { display: flex; justify-content: space-between; gap: 32px; align-items: end; }
.social-links { display: flex; flex-wrap: wrap; gap: 10px; }
.social-link { border-bottom: 1px solid var(--violet-line); padding: 10px 0; color: var(--ink-soft); min-width: 130px; display: flex; justify-content: space-between; gap: 22px; }
.social-link:hover { color: var(--violet-light); border-color: var(--violet-mid); text-decoration: none; }

@media (max-width: 700px) {
  .haqthon-grid, .social-wrap { grid-template-columns: 1fr; display: grid; }
  .social-wrap { gap: 8px; }
}

/* ============================================================
   REGISTER CTA
   ============================================================ */
.register-cta {
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, var(--violet-deep) 0%, #3a1258 50%, #2a0f40 100%);
  padding: 100px 0;
}
#register-wave-canvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  pointer-events: none; opacity: 0.2;
}
.register-wrap { position: relative; z-index: 2; }
.register-copy { max-width: 580px; }
.register-copy .section-kicker { color: rgba(255,255,255,0.6); }
.register-copy h2 {
  font-size: clamp(2.4rem, 4.5vw, 3.8rem);
  color: var(--white); margin-bottom: 12px; letter-spacing: -0.02em;
}
.register-copy > p { font-size: 1.2rem; color: rgba(255,255,255,0.72); margin-bottom: 40px; max-width: 38ch; }

.btn-register {
  background: var(--white); color: var(--violet-deep);
  font-size: 1.05rem; padding: 16px 36px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.25);
  margin-bottom: 24px;
  animation: glow 3s ease infinite;
}
.btn-register:hover { background: var(--violet-pale); color: var(--violet-deep); box-shadow: 0 8px 32px rgba(0,0,0,0.3); }
.register-meta { font-size: 0.8rem; color: rgba(255,255,255,0.5); }

.register-particles { position: absolute; inset: 0; pointer-events: none; }
.reg-particle {
  position: absolute; left: var(--x); top: var(--y);
  width: var(--size); height: var(--size); border-radius: 50%;
  background: rgba(255,255,255,0.4);
  animation: particleFloat 4s ease-in-out var(--delay) infinite;
}

/* ============================================================
   FAQ
   ============================================================ */
.faq-list { max-width: 720px; margin-bottom: 40px; }
.faq-item { border-bottom: 1px solid var(--violet-line); }
.faq-item:first-child { border-top: 1px solid var(--violet-line); }
.faq-question {
  width: 100%; background: none; border: none;
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 0; cursor: pointer; text-align: left;
  font-family: var(--font-display); font-size: 1rem; font-weight: 600; color: var(--ink);
  gap: 16px; transition: color 0.2s;
}
.faq-question:hover { color: var(--violet-deep); }
.faq-chevron { flex-shrink: 0; transition: transform 0.3s ease; color: var(--violet-light); }
.faq-question[aria-expanded="true"] .faq-chevron { transform: rotate(180deg); color: var(--violet); }
.faq-answer {
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}
.faq-answer.open { max-height: 300px; padding-bottom: 18px; }
.faq-answer p { font-size: 0.95rem; color: var(--ink-soft); margin: 0; }
.faq-answer a { color: var(--violet-deep); }

/* DO NOT CLICK */
.do-not-click-wrap { margin-top: 24px; }
.do-not-click-btn {
  font-family: var(--font-mono); font-size: 0.72rem;
  color: var(--ink-faint); border: 1px dashed var(--violet-line);
  background: transparent; padding: 6px 14px; border-radius: var(--radius);
  cursor: pointer; transition: all 0.2s; letter-spacing: 0.06em;
}
.do-not-click-btn:hover { border-color: var(--violet-light); color: var(--violet); }

.dnc-message {
  position: fixed; bottom: 90px; left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: var(--surface); border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg); padding: 16px 24px;
  box-shadow: var(--shadow-lg); font-family: var(--font-mono); font-size: 0.84rem;
  color: var(--ink); z-index: 9999; max-width: 380px; text-align: center;
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s, transform 0.3s;
}
.dnc-message.show { opacity: 1; pointer-events: auto; transform: translateX(-50%) translateY(0); }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  padding: 56px 0 40px;
  border-top: 1px solid var(--violet-line);
  background: var(--bg);
  position: relative;
}
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }

.footer-brand { display: flex; flex-direction: column; gap: 12px; }
.footer-brand-link { display: flex; align-items: center; gap: 8px; color: var(--ink-soft); font-size: 0.96rem; }
.footer-brand-link:hover { color: var(--violet-deep); text-decoration: none; }
.footer-tagline { font-size: 0.88rem; color: var(--ink-faint); line-height: 1.6; }
.footer-feynman-trigger { display: inline-block; cursor: default; color: var(--ink-faint); margin-top: 4px; }

.footer-col h4 { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint); font-weight: 400; letter-spacing: 0.06em; margin-bottom: 14px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { font-size: 0.92rem; color: var(--ink-soft); }
.footer-col a:hover { color: var(--violet-deep); text-decoration: none; }

.footer-bottom {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  padding-top: 24px; border-top: 1px solid var(--violet-line);
  font-size: 0.8rem; color: var(--ink-faint); font-family: var(--font-mono);
}
.footer-state { opacity: 0.6; }

@media (max-width: 700px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 460px) { .footer-grid { grid-template-columns: 1fr; } .footer-bottom { flex-direction: column; } }

/* ============================================================
   FEYNMAN POPUP
   ============================================================ */
.feynman-popup {
  position: fixed; bottom: 32px; right: 32px;
  background: var(--surface); border: 1px solid var(--violet-line);
  border-radius: var(--radius-lg);
  padding: 20px 24px; box-shadow: var(--shadow-lg);
  max-width: 320px; z-index: 9999;
  opacity: 0; transform: translateY(10px) scale(0.96);
  transition: opacity 0.35s ease, transform 0.35s ease;
  pointer-events: none;
}
.feynman-popup.show { opacity: 1; transform: none; pointer-events: auto; }
.feynman-mark { font-size: 0.68rem; color: var(--violet); margin-bottom: 8px; letter-spacing: 0.06em; }
.feynman-popup blockquote {
  font-family: var(--font-body); font-style: italic;
  font-size: 0.96rem; color: var(--ink); border-left: 2px solid var(--violet-light);
  padding-left: 14px; margin: 0;
}

/* ============================================================
   KONAMI OVERLAY
   ============================================================ */
.konami-overlay {
  position: fixed; inset: 0; z-index: 10000;
  background: rgba(28,17,48,0.96);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none;
  transition: opacity 0.4s ease;
}
.konami-overlay.show { opacity: 1; pointer-events: auto; }
.konami-inner {
  text-align: center; max-width: 560px; padding: 48px 32px; color: var(--white);
}
.konami-badge {
  font-size: 0.7rem; letter-spacing: 0.14em;
  color: var(--violet-light); margin-bottom: 24px;
}
.konami-inner h2 { color: var(--white); font-size: 2.2rem; margin-bottom: 16px; }
.konami-inner p { color: rgba(255,255,255,0.75); margin-bottom: 28px; font-size: 1rem; }
.konami-eq { font-size: 1rem; color: var(--violet-light); margin-bottom: 32px; }

/* ============================================================
   ENTANGLEMENT SVG
   ============================================================ */
.entanglement-svg line {
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 0.3s;
}

/* ============================================================
   UTILITY
   ============================================================ */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border-width: 0;
}