:root {
  color-scheme: light;
  --background: #f7fafd;
  --surface: rgba(255, 255, 255, 0.94);
  --surface-solid: #ffffff;
  --primary: #3568c6;
  --primary-hover: #2b58aa;
  --actual: #159b9a;
  --text: #17324a;
  --muted: #5b7083;
  --border: #d8e4ef;
  --focus: #7aa2ee;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--background);
}

body {
  min-height: 100dvh;
  margin: 0;
  overflow-x: hidden;
  color: var(--text);
  background: var(--background);
}

.skip-link {
  position: fixed;
  z-index: 30;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  color: #fff;
  background: var(--text);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.hero-art,
.hero-art img,
.ambient-layer {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-art {
  z-index: 0;
}

.hero-art img {
  object-fit: cover;
  object-position: center;
}

.ambient-layer {
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(247, 250, 253, 0.28), transparent 58%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.12), rgba(247, 250, 253, 0.2));
  pointer-events: none;
}

.portal-shell {
  position: relative;
  z-index: 2;
  display: grid;
  min-height: 100dvh;
  align-items: center;
  padding: max(32px, env(safe-area-inset-top)) clamp(24px, 7vw, 120px)
    max(32px, env(safe-area-inset-bottom));
}

.entry-panel {
  width: min(560px, 100%);
  padding: clamp(28px, 4vw, 48px);
  border: 1px solid rgba(216, 228, 239, 0.95);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 24px 70px rgba(35, 74, 104, 0.15);
  backdrop-filter: blur(18px);
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 36px;
}

.brand-mark {
  display: grid;
  width: 44px;
  height: 44px;
  place-items: center;
  border-radius: 13px;
  color: #fff;
  background: linear-gradient(145deg, var(--primary), #3a70d9);
  box-shadow: 0 8px 20px rgba(53, 104, 198, 0.24);
  font-size: 23px;
  font-weight: 800;
}

.brand-row div {
  display: grid;
  gap: 2px;
}

.brand-row strong {
  font-size: 19px;
  letter-spacing: 0.04em;
}

.brand-row span:last-child {
  color: var(--muted);
  font-size: 13px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.12em;
}

h1 {
  max-width: 11em;
  margin: 0;
  font-size: clamp(34px, 3.7vw, 52px);
  line-height: 1.16;
  letter-spacing: -0.04em;
}

.lead {
  max-width: 34em;
  margin: 20px 0 30px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.entry-options {
  display: grid;
  gap: 12px;
}

.entry-card {
  display: grid;
  min-height: 82px;
  grid-template-columns: 48px minmax(0, 1fr) 28px;
  align-items: center;
  gap: 14px;
  padding: 15px 16px;
  border: 1px solid var(--border);
  border-radius: 16px;
  color: var(--text);
  background: rgba(255, 255, 255, 0.88);
  text-decoration: none;
  box-shadow: 0 5px 18px rgba(23, 50, 74, 0.04);
  transition: border-color 180ms ease, box-shadow 180ms ease,
    background-color 180ms ease, transform 180ms ease;
  touch-action: manipulation;
}

.entry-card:hover {
  border-color: #9db9e7;
  background: var(--surface-solid);
  box-shadow: 0 10px 28px rgba(35, 74, 104, 0.12);
  transform: translateY(-2px);
}

.entry-card:focus-visible,
.skip-link:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

.entry-icon {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border-radius: 14px;
  color: var(--primary);
  background: #edf4ff;
}

.entry-card--volunteer .entry-icon {
  color: #087a6a;
  background: #eaf8f4;
}

.entry-icon svg {
  width: 25px;
  height: 25px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.entry-copy {
  display: grid;
  min-width: 0;
  gap: 5px;
}

.entry-copy strong {
  font-size: 17px;
}

.entry-copy small {
  overflow-wrap: anywhere;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.entry-arrow {
  color: var(--primary);
  font-size: 22px;
  font-weight: 700;
}

.entry-card--volunteer .entry-arrow {
  color: var(--actual);
}

.research-notice {
  margin: 22px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.7;
}

@media (max-width: 700px) {
  .hero-art img {
    object-position: center;
  }

  .ambient-layer {
    background: rgba(247, 250, 253, 0.28);
  }

  .portal-shell {
    align-items: end;
    padding: max(20px, env(safe-area-inset-top)) 16px
      max(20px, env(safe-area-inset-bottom));
  }

  .entry-panel {
    padding: 26px 22px;
    border-radius: 22px;
    background: rgba(255, 255, 255, 0.965);
    backdrop-filter: blur(14px);
  }

  .brand-row {
    margin-bottom: 24px;
  }

  h1 {
    font-size: clamp(31px, 9.2vw, 42px);
  }

  .lead {
    margin: 16px 0 24px;
    line-height: 1.65;
  }
}

@media (max-width: 380px) {
  .entry-panel {
    padding: 22px 18px;
  }

  .entry-card {
    grid-template-columns: 44px minmax(0, 1fr) 22px;
    gap: 10px;
    padding-inline: 12px;
  }

  .entry-icon {
    width: 44px;
    height: 44px;
  }
}

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

  .entry-card:hover {
    transform: none;
  }
}

@supports not (backdrop-filter: blur(1px)) {
  .entry-panel {
    background: #fff;
  }
}