:root {
  --vt-navy: #2b3a67;
  --vt-blue: #4ca9e1;
  --vt-cyan: #8ee4e6;
  --vt-pink: #ffb7c5;
  --page: #dfe9f5;
  --ink: #1e293b;
  --muted: #64748b;
  --frame-gap: clamp(5px, 0.8vw, 9px);
  --frame-radius: 20px;
  --shadow: 0 24px 60px rgba(43, 58, 103, 0.14);
  --font-display: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", "Outfit", sans-serif;
  --font-body: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", "Segoe UI", sans-serif;
  --font-en: "Outfit", "Segoe UI", "Microsoft YaHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  min-height: 100%;
}

body {
  color: var(--ink);
  font-family: var(--font-body);
  background: var(--page);
  overflow-x: hidden;
}

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

.frame {
  position: relative;
  z-index: 1;
  min-height: calc(100vh - var(--frame-gap) * 2);
  margin: var(--frame-gap);
  border-radius: var(--frame-radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.55);
}

.stage {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.bg-video,
.bg-fallback {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bg-fallback {
  background:
    radial-gradient(ellipse 80% 60% at 20% 20%, rgba(255, 183, 197, 0.55), transparent 55%),
    radial-gradient(ellipse 70% 50% at 85% 15%, rgba(142, 228, 230, 0.5), transparent 50%),
    radial-gradient(ellipse 60% 55% at 70% 80%, rgba(76, 169, 225, 0.45), transparent 55%),
    linear-gradient(160deg, #e8f4ff 0%, #f7fbff 45%, #ffeef3 100%);
  background-size: 140% 140%;
  animation: drift 28s ease-in-out infinite alternate;
}

.bg-video.is-ready + .bg-fallback {
  opacity: 0;
  transition: opacity 1.2s ease;
}

.bg-veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(240, 247, 255, 0.28) 0%, rgba(240, 247, 255, 0.55) 55%, rgba(240, 247, 255, 0.72) 100%),
    radial-gradient(ellipse at center, transparent 20%, rgba(43, 58, 103, 0.08) 100%);
}

.bg-grain {
  position: absolute;
  inset: 0;
  opacity: 0.04;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: multiply;
}

@keyframes drift {
  from { background-position: 0% 20%, 100% 0%, 40% 100%, 0 0; }
  to { background-position: 30% 40%, 70% 30%, 60% 70%, 0 0; }
}

.topbar,
.hero {
  position: relative;
  z-index: 1;
}

.topbar {
  display: flex;
  align-items: center;
  padding: 22px 28px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--vt-navy);
}

.brand-orb {
  width: 28px;
  height: 28px;
  border-radius: 40% 60% 55% 45%;
  background: linear-gradient(135deg, var(--vt-cyan), var(--vt-blue) 45%, var(--vt-pink));
  animation: morph 8s ease-in-out infinite;
}

.brand-logo {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  object-fit: contain;
  display: block;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(43, 58, 103, 0.18);
}

@keyframes morph {
  0%, 100% { border-radius: 40% 60% 55% 45%; transform: rotate(0deg); }
  50% { border-radius: 60% 40% 35% 65%; transform: rotate(12deg); }
}

.hero {
  min-height: calc(100vh - var(--frame-gap) * 2 - 88px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 24px 80px;
}

.eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-en);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 0.78rem;
  color: var(--vt-blue);
  font-weight: 700;
}

.title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.6rem, 7vw, 5rem);
  line-height: 1.15;
  letter-spacing: 0.04em;
  color: var(--vt-navy);
}

.lead {
  margin: 18px auto 0;
  max-width: 34rem;
  font-size: 1.08rem;
  line-height: 1.7;
  color: var(--muted);
}

.cta {
  margin-top: 36px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}

.btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 0 26px;
  border-radius: 14px;
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 700;
  transition: transform 0.25s ease, background 0.25s ease, box-shadow 0.25s ease;
}

.btn-primary {
  background: var(--vt-navy);
  color: #fff;
  box-shadow: 0 12px 28px rgba(43, 58, 103, 0.28);
}

.btn-primary:hover {
  transform: translateY(-2px);
  background: #354875;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.55);
  color: var(--vt-navy);
  border: 1px solid rgba(255, 255, 255, 0.75);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.btn-ghost:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.82);
}

.hint {
  margin-top: 22px;
  font-size: 0.9rem;
  color: var(--muted);
}

.fade-up {
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.9s ease forwards;
}

.delay-1 { animation-delay: 0.12s; }
.delay-2 { animation-delay: 0.24s; }
.delay-3 { animation-delay: 0.36s; }
.delay-4 { animation-delay: 0.48s; }

@keyframes rise {
  to { opacity: 1; transform: translateY(0); }
}

.modal[hidden] {
  display: none;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 40;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgba(43, 58, 103, 0.35);
  backdrop-filter: blur(6px);
}

.modal-panel {
  position: relative;
  width: min(100%, 440px);
  padding: 32px 28px 28px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow);
  text-align: left;
}

.modal-panel h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  color: var(--vt-navy);
  font-size: 1.4rem;
}

.modal-panel p {
  margin: 0 0 10px;
  color: var(--muted);
  line-height: 1.7;
}

.modal-note {
  font-size: 0.9rem;
}

.modal-close {
  position: absolute;
  top: 10px;
  right: 14px;
  border: 0;
  background: transparent;
  font-size: 1.6rem;
  line-height: 1;
  color: var(--muted);
  cursor: pointer;
}

@media (max-width: 720px) {
  .cta {
    width: 100%;
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}