:root {
  color-scheme: dark;
  --navy: #07111f;
  --deep-blue: #0b1c34;
  --cyan: #57d6ff;
  --violet: #8d5bf7;
  --text: #f4f8ff;
  --muted: rgba(244, 248, 255, 0.68);
  --border: rgba(255, 255, 255, 0.13);
  --danger: #ff8a9c;
  --success: #7ef2b8;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--navy);
  color: var(--text);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }

.site-header {
  position: fixed;
  inset: 42px 0 auto;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 15px min(6vw, 72px);
  background: linear-gradient(180deg, rgba(7,17,31,0.88), rgba(7,17,31,0));
}

.brand { font-size: 15px; font-weight: 900; letter-spacing: 0.14em; }
.nav-links { display: flex; gap: 28px; font-size: 14px; color: var(--muted); }
.nav-links a:hover { color: var(--text); }

.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  overflow: hidden;
  padding: 112px min(6vw, 72px) 76px;
}

.hero-background {
  position: absolute;
  inset: -8%;
  background:
    radial-gradient(circle at 15% 20%, rgba(61,130,246,0.42), transparent 28%),
    radial-gradient(circle at 78% 26%, rgba(141,91,247,0.35), transparent 30%),
    radial-gradient(circle at 58% 88%, rgba(87,214,255,0.28), transparent 34%),
    linear-gradient(145deg, #040a15, #081a31 52%, #030912);
}

.hero-background::before,
.hero-background::after {
  content: "";
  position: absolute;
  border: 1px solid rgba(255,255,255,0.09);
  border-radius: 50%;
}

.hero-background::before {
  width: 72vmin;
  height: 72vmin;
  right: 6vw;
  bottom: -12vmin;
  animation: floatSlow 12s ease-in-out infinite alternate;
}

.hero-background::after {
  width: 98vmin;
  height: 98vmin;
  top: -25vmin;
  left: -18vmin;
  border-color: rgba(255,255,255,0.06);
  animation: floatSlow 16s ease-in-out infinite alternate-reverse;
}

.hero-inner { position: relative; z-index: 1; width: min(1060px, 100%); text-align: center; }
.hero-kicker { margin: 0 0 20px; color: var(--cyan); font-size: 13px; letter-spacing: 0.42em; text-transform: uppercase; }

h1 {
  margin: 0;
  font-size: clamp(43px, 9.2vw, 112px);
  line-height: 1.04;
  font-weight: 900;
  letter-spacing: -0.04em;
  text-wrap: balance;
  background: linear-gradient(96deg, #ffffff 16%, #a9d8ff 49%, #9d7dff 83%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-subtitle {
  width: min(710px, 100%);
  margin: 26px auto 0;
  color: var(--muted);
  font-size: clamp(16px, 2.2vw, 22px);
  font-weight: 300;
}

.event-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
  color: rgba(244,248,255,0.82);
  font-size: 14px;
}

.event-meta span {
  padding: 9px 17px;
  border: 1px solid var(--border);
  border-radius: 100px;
  background: rgba(255,255,255,0.055);
  backdrop-filter: blur(12px);
}

.hero-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; margin-top: 42px; }

.primary-button,
.ghost-button,
.submit-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 13px 30px;
  border: 0;
  border-radius: 100px;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.primary-button,
.submit-button {
  color: #071021;
  background: linear-gradient(96deg, #7de6ff, #3d82f6 56%, #8d5bf7);
  box-shadow: 0 15px 42px rgba(61,130,246,0.38);
}

.ghost-button {
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.34);
  background: rgba(255,255,255,0.07);
}

.ghost-button.dark { border-color: rgba(7,17,31,0.2); color: var(--deep-blue); }
.primary-button:hover,
.ghost-button:hover,
.submit-button:hover { transform: translateY(-2px); }

.scroll-cue {
  position: absolute;
  bottom: 24px;
  left: 50%;
  width: 26px;
  height: 44px;
  margin-left: -13px;
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 30px;
}

.scroll-cue span {
  position: absolute;
  top: 9px;
  left: 50%;
  width: 4px;
  height: 9px;
  margin-left: -2px;
  border-radius: 4px;
  background: var(--cyan);
  animation: scrollDot 1.6s infinite;
}

.section { padding: 100px min(6vw, 72px); background: var(--navy); }
.video-section { background: linear-gradient(180deg, var(--navy), #081526); }
.video-card {
  width: min(960px, 100%);
  margin: 0 auto;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: rgba(255,255,255,0.045);
  box-shadow: 0 28px 80px rgba(0,0,0,0.28);
}
.video-card video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 16px;
  background: #000;
}
.video-card figcaption {
  padding: 16px 6px 4px;
  color: var(--muted);
  font-size: 14px;
  text-align: center;
}
.speakers { background: #050d19; }
.section-heading { margin-bottom: 48px; }
.section-heading span { display: block; color: var(--cyan); font-size: 12px; letter-spacing: 0.35em; text-transform: uppercase; }
.section-heading h2 { margin: 10px 0 0; font-size: clamp(30px, 4.4vw, 52px); line-height: 1.15; letter-spacing: -0.03em; }

.card-grid,
.speaker-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }

.info-card,
.speaker-card,
.registration-form,
.success-panel {
  border: 1px solid var(--border);
  border-radius: 24px;
  background: linear-gradient(155deg, rgba(255,255,255,0.09), rgba(255,255,255,0.03));
  box-shadow: 0 25px 70px rgba(0,0,0,0.2);
  backdrop-filter: blur(18px);
}

.info-card { padding: 30px; }
.info-card h3,
.speaker-card h3 { margin: 0 0 10px; font-size: 20px; }
.info-card p { margin: 0; color: var(--muted); font-size: 15px; }
.info-icon { margin-bottom: 27px; color: var(--cyan); font-size: 13px; font-weight: 900; }

.speaker-card { padding: 30px; text-align: center; }
.avatar {
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  margin: 0 auto 22px;
  border-radius: 50%;
  color: #07111f;
  background: linear-gradient(135deg, #7de6ff, #8d5bf7);
  font-size: 25px;
  font-weight: 700;
}

.speaker-card p { margin: 0; color: var(--muted); font-size: 14px; }
.register-section { background: linear-gradient(180deg, #050d19, var(--navy)); }

.register-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
  gap: 46px;
  align-items: center;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.register-copy > p { margin-top: 0; color: var(--muted); }
.register-notes { margin: 0; padding-left: 20px; color: var(--muted); font-size: 14px; }
.register-notes li + li { margin-top: 9px; }
.registration-form { padding: clamp(24px, 4vw, 44px); }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.registration-form label { display: block; }
.registration-form label span { display: block; margin-bottom: 8px; color: rgba(244,248,255,0.8); font-size: 14px; }
.registration-form label span b { color: var(--cyan); }

.registration-form input,
.registration-form textarea {
  width: 100%;
  min-height: 50px;
  padding: 13px 15px;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(255,255,255,0.06);
  font: inherit;
  outline: none;
  resize: vertical;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.registration-form input:focus,
.registration-form textarea:focus {
  border-color: rgba(87,214,255,0.75);
  box-shadow: 0 0 0 4px rgba(87,214,255,0.11);
}

.registration-form input.invalid,
.registration-form textarea.invalid { border-color: var(--danger); }
.registration-form small { display: block; min-height: 20px; margin-top: 6px; color: var(--danger); font-size: 12px; }
.full-width { margin-top: 18px; }
.submit-button { width: 100%; margin-top: 8px; }
.submit-button:disabled { opacity: 0.68; cursor: wait; transform: none; }
#form-status { min-height: 24px; margin: 14px 0 0; color: var(--danger); font-size: 14px; text-align: center; }

.success-panel { padding: 50px 35px; text-align: center; }
.success-panel h2 { margin: 18px 0 10px; font-size: 31px; }
.success-panel p { margin: 0 0 30px; color: var(--muted); }
.success-mark {
  width: 68px;
  height: 68px;
  display: grid;
  place-items: center;
  margin: 0 auto;
  border-radius: 50%;
  color: #07111f;
  background: linear-gradient(135deg, #7ef2b8, #57d6ff);
  font-size: 29px;
  font-weight: 900;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 32px min(6vw, 72px) calc(34px + env(safe-area-inset-bottom));
  border-top: 1px solid rgba(255,255,255,0.08);
  color: var(--muted);
  font-size: 13px;
}

.site-footer strong { color: var(--text); }
.site-footer a { color: var(--cyan); }

.admin-page { padding: 54px min(6vw, 72px) 72px; }
.admin-header { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 28px; }
.admin-header h1 { font-size: clamp(29px, 5vw, 48px); letter-spacing: -0.03em; }
.admin-header p { margin: 10px 0 0; color: var(--muted); }
.export-link { padding: 12px 20px; border: 1px solid var(--border); border-radius: 100px; background: rgba(255,255,255,0.06); white-space: nowrap; }
.stat-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 15px; margin-bottom: 20px; }
.stat-card { padding: 22px; border: 1px solid var(--border); border-radius: 18px; background: rgba(255,255,255,0.045); }
.stat-card strong { display: block; font-size: 32px; line-height: 1.2; }
.stat-card span { color: var(--muted); font-size: 13px; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 22px; background: rgba(255,255,255,0.04); }
.admin-table { width: 100%; min-width: 760px; border-collapse: collapse; }
.admin-table th,
.admin-table td { padding: 15px 17px; border-bottom: 1px solid rgba(255,255,255,0.07); font-size: 14px; text-align: left; }
.admin-table th { color: var(--muted); font-weight: 500; white-space: nowrap; }
.admin-table tr:last-child td { border-bottom: 0; }
.empty-state { padding: 50px 20px; color: var(--muted); text-align: center; }
.admin-actions { display: flex; align-items: center; justify-content: space-between; gap: 15px; margin-top: 22px; }
.refresh-button { padding: 11px 20px; border: 0; border-radius: 100px; color: #071021; background: #7de6ff; cursor: pointer; font-weight: 700; }

@keyframes floatSlow { from { transform: translateY(0); } to { transform: translateY(36px); } }
@keyframes scrollDot { 0% { opacity: 0; transform: translateY(0); } 35% { opacity: 1; } 100% { opacity: 0; transform: translateY(18px); } }

@media (min-width: 901px) and (max-width: 1120px) {
  .card-grid,
  .speaker-grid { grid-template-columns: 1fr 1fr; }
  .card-grid > :last-child,
  .speaker-grid > :last-child { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .site-header { padding: 14px 20px; }
  .nav-links { display: none; }
  .hero { padding-top: 88px; }
  .section { padding: 76px 20px; }
  .card-grid,
  .speaker-grid,
  .register-layout,
  .form-grid,
  .stat-grid { grid-template-columns: 1fr; }
  .register-layout { gap: 32px; }
  .admin-page { padding: 44px 16px 52px; }
  .admin-header { flex-direction: column; align-items: start; }
}

@media (max-width: 520px) {
  html { font-size: 15px; }
  .hero { padding-right: 17px; padding-left: 17px; }
  .hero-kicker { font-size: 11px; letter-spacing: 0.22em; }
  h1 br { display: none; }
  .event-meta { gap: 9px; }
  .event-meta span { width: 100%; padding: 10px 12px; text-align: center; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions > *,
  .submit-button,
  .export-link { width: 100%; }
  .registration-form { border-radius: 20px; }
  .registration-form input,
  .registration-form textarea { font-size: 16px; }
  .scroll-cue { display: none; }
  .video-card { padding: 9px; border-radius: 18px; }
  .video-card video { border-radius: 11px; }
  .video-card figcaption { padding-bottom: 0; }
  .site-footer { justify-content: center; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}