:root {
  --cover-bg: #f8fafc;
  --cover-surface: rgba(255, 255, 255, 0.1);
  --cover-text: #111827;
  --cover-heading: #0f172a;
  --cover-body: #374151;
  --cover-muted: #6b7280;
  --cover-blue: #1d4ed8;
  --cover-teal: #0f766e;
  --cover-gold: #b45309;
  --cover-border: rgba(17, 24, 39, 0.14);
  --cover-font: "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  --cover-container: 1180px;
  --cover-radius: 24px;
  --cover-shadow: 0 24px 60px rgba(15, 23, 42, 0.1);
}

html,
body {
  background: var(--cover-bg);
  font-family: var(--cover-font);
}

body {
  color: var(--cover-text);
  background:
    linear-gradient(180deg, rgba(248, 250, 252, 0.34), rgba(210, 218, 224, 0.32)),
    var(--cover-bg);
}

.cover-frame {
  inset: 24px 38px;
  max-width: none;
  margin: 0;
  border: 1px solid var(--cover-border);
  border-radius: 8px;
  background: var(--cover-surface);
  box-shadow: var(--cover-shadow);
  backdrop-filter: blur(4px) saturate(1.04);
  -webkit-backdrop-filter: blur(4px) saturate(1.04);
}

.cover-frame::before {
  background:
    linear-gradient(90deg, rgba(15, 23, 42, 0.025) 1px, transparent 1px),
    linear-gradient(180deg, rgba(15, 23, 42, 0.02) 1px, transparent 1px);
  background-size: 52px 52px;
  mix-blend-mode: normal;
  opacity: 0.32;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.44), transparent 78%);
}

.cover-frame::after {
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.42),
    inset 0 -1px 0 rgba(15, 23, 42, 0.02);
}

.site-nav {
  min-height: 66px;
  padding: 0 clamp(26px, 3vw, 50px);
  color: var(--cover-heading);
  font-size: 14px;
}

.wordmark {
  gap: 10px;
}

.wordmark-mark {
  width: 36px;
  height: 36px;
  border: 0;
  border-radius: 12px;
  color: #ffffff;
  background: var(--cover-heading);
  font-family: var(--cover-font);
  font-size: 16px;
  font-style: normal;
  font-weight: 800;
}

.wordmark span:last-child {
  font-family: var(--cover-font);
  font-size: 17px;
  font-weight: 700;
}

.nav-menu {
  gap: clamp(20px, 4vw, 56px);
}

.nav-menu a,
.enter-link {
  color: var(--cover-body);
  font-size: 14px;
  font-weight: 560;
}

.nav-menu a::after,
.enter-link::after {
  bottom: 4px;
  background: var(--cover-blue);
}

.mountain-layer {
  opacity: 0.98;
  filter: grayscale(0.12) saturate(0.82) contrast(1.08) brightness(0.9);
  background-position: center 42%;
}

.mountain-layer::before {
  background:
    linear-gradient(180deg, rgba(248, 250, 252, 0.34) 0%, rgba(248, 250, 252, 0.16) 31%, rgba(248, 250, 252, 0.02) 58%),
    linear-gradient(90deg, rgba(248, 250, 252, 0.16), transparent 24%, transparent 76%, rgba(248, 250, 252, 0.18));
}

.mountain-layer::after {
  height: 46%;
  background: linear-gradient(0deg, rgba(15, 23, 42, 0.5), rgba(15, 23, 42, 0.02));
}

.cloud-canvas {
  opacity: 0.12;
  mix-blend-mode: multiply;
}

.altitude-line {
  opacity: 0.22;
  background: linear-gradient(180deg, transparent, var(--cover-heading), transparent);
}

.altitude-line::before,
.altitude-line::after {
  border-color: var(--cover-heading);
}

.hero-copy {
  justify-items: center;
  gap: 14px;
  width: min(860px, calc(100vw - 96px));
  margin-top: clamp(124px, 21vh, 198px);
  color: var(--cover-heading);
  perspective: 960px;
  text-align: center;
}

.hero-kicker {
  color: rgba(12, 92, 84, 0.92);
  font-size: clamp(12px, 1.15vw, 15px);
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-shadow: 0 1px 18px rgba(255, 255, 255, 0.5);
}

.hero-title {
  color: #1b1230;
  font-family: var(--cover-font);
  font-size: clamp(34px, 4.5vw, 64px);
  font-style: normal;
  font-weight: 820;
  line-height: 0.96;
  letter-spacing: 0.04em;
  text-shadow:
    0 1px 0 rgba(255, 255, 255, 0.5),
    1px 1px 0 rgba(69, 48, 103, 0.72),
    2px 2px 0 rgba(43, 30, 70, 0.48),
    0 14px 30px rgba(20, 13, 38, 0.22);
  transform: perspective(960px) rotateX(8deg) rotateY(-5deg) skewX(-2deg);
  transform-origin: 50% 62%;
}

.hero-line {
  max-width: 620px;
  margin-top: 2px;
  color: rgba(255, 255, 255, 0.92);
  font-size: clamp(17px, 1.42vw, 22px);
  font-weight: 700;
  line-height: 1.6;
  text-shadow:
    0 2px 16px rgba(15, 23, 42, 0.54),
    0 0 1px rgba(15, 23, 42, 0.68);
}

.enter-button {
  min-height: 46px;
  margin-top: 2px;
  padding: 0 19px;
  border: 1px solid rgba(15, 23, 42, 0.8);
  border-radius: 999px;
  color: #ffffff;
  background: var(--cover-heading);
  box-shadow: 0 14px 32px rgba(15, 23, 42, 0.16);
  font-weight: 700;
}

.enter-button:hover {
  transform: translateY(-2px);
  background: #111827;
  box-shadow: 0 20px 44px rgba(15, 23, 42, 0.18);
}

.side-index,
.edge-caption {
  color: var(--cover-muted);
  font-family: var(--cover-font);
  font-style: normal;
  text-shadow: none;
}

.side-index {
  font-weight: 700;
  letter-spacing: 0.08em;
}

.edge-caption small {
  color: var(--cover-muted);
}

@media (max-width: 820px) {
  .cover-frame {
    min-height: calc(100vh - 24px);
    margin: 12px;
    inset: auto;
  }

  .site-nav {
    min-height: 68px;
    padding: 0 16px;
  }

  .hero-copy {
    width: calc(100vw - 56px);
    margin-top: 88px;
    text-align: left;
    justify-items: start;
  }

  .hero-title {
    font-size: clamp(30px, 10.4vw, 50px);
  }

  .hero-line {
    max-width: 420px;
    font-size: 15px;
  }

  .mountain-layer {
    inset: -2% -30% -3% -24%;
    background-position: 50% 58%;
  }
}

@media (max-width: 480px) {
  .cover-frame {
    min-height: calc(100vh - 18px);
    margin: 9px;
    border-radius: 20px;
  }

  .hero-copy {
    width: calc(100vw - 42px);
    margin-top: 76px;
  }

  .hero-title {
    font-size: clamp(28px, 11vw, 44px);
    transform: perspective(760px) rotateX(6deg) rotateY(-3deg) skewX(-1deg);
  }

  .enter-button {
    width: 100%;
  }

  .edge-caption {
    display: none;
  }
}