/* Atlas platform landing */

:root {
  --font-sans:
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    sans-serif;

  --ink-900: #0f172a;
  --ink-800: #1f2a3d;
  --ink-600: #3b4a64;
  --ink-500: #5a6577;
  --ink-400: #7a8395;
  --ink-50: #f3f5f8;

  --surface: #ffffff;
  --line: rgba(15, 23, 42, 0.08);
  --line-strong: rgba(15, 23, 42, 0.14);

  --brand-500: #fe5e03;
  --brand-600: #e04a00;
  --brand-soft: rgba(254, 94, 3, 0.1);
  --brand-glow: rgba(254, 94, 3, 0.22);

  --accent-500: #1f4ea3;
  --accent-600: #163d85;
  --accent-soft: rgba(31, 78, 163, 0.1);
  --accent-glow: rgba(31, 78, 163, 0.18);

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 2px 6px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 2px 6px rgba(15, 23, 42, 0.06), 0 8px 24px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 4px 12px rgba(15, 23, 42, 0.08), 0 16px 40px rgba(15, 23, 42, 0.08);

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 220ms;
  --radius: 18px;
  --radius-sm: 12px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink-800);
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(31, 78, 163, 0.12), transparent 60%),
    radial-gradient(ellipse 50% 40% at 100% 100%, rgba(254, 94, 3, 0.08), transparent 55%),
    linear-gradient(180deg, #f7f9fc 0%, #eef2f8 100%);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
}

.admin-link {
  position: fixed;
  top: 16px;
  right: 20px;
  z-index: 100;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-600);
  text-decoration: none;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.admin-link:hover {
  color: var(--accent-600);
  border-color: rgba(31, 78, 163, 0.35);
  box-shadow: var(--shadow-md);
}

.admin-link svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.back-link {
  position: fixed;
  top: 16px;
  left: 20px;
  z-index: 100;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-600);
  text-decoration: none;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.back-link:hover {
  color: var(--accent-600);
}

.back-link svg {
  width: 16px;
  height: 16px;
}

.shell {
  width: min(960px, 100%);
  margin: 0 auto;
  padding: 72px 20px 40px;
}

.brand {
  text-align: center;
  margin-bottom: 48px;
}

.brand__logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  margin-bottom: 20px;
  border-radius: 14px;
  box-shadow: var(--shadow-md);
}

.brand__logo img {
  width: 100%;
  height: 100%;
  display: block;
}

.brand__title {
  margin: 0 0 10px;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-900);
  line-height: 1.2;
}

.brand__tagline {
  margin: 0;
  font-size: clamp(0.9375rem, 2vw, 1.0625rem);
  color: var(--ink-500);
  letter-spacing: 0.06em;
}

.entries {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

@media (max-width: 640px) {
  .entries {
    grid-template-columns: 1fr;
    max-width: 420px;
    margin: 0 auto;
  }
}

.entry {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 28px;
  text-decoration: none;
  color: var(--ink-800);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--dur) var(--ease-out),
    box-shadow var(--dur) var(--ease-out),
    border-color var(--dur) var(--ease-out);
}

.entry::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transition: opacity var(--dur) var(--ease-out);
  pointer-events: none;
}

.entry--gaokao::before {
  background: linear-gradient(135deg, var(--brand-soft) 0%, transparent 55%);
}

.entry--k12::before {
  background: linear-gradient(135deg, var(--accent-soft) 0%, transparent 55%);
}

.entry:hover,
.entry:focus-visible {
  transform: translateY(-4px);
  border-color: var(--line-strong);
}

.entry--gaokao:hover,
.entry--gaokao:focus-visible {
  box-shadow: var(--shadow-lg), 0 12px 28px var(--brand-glow);
}

.entry--k12:hover,
.entry--k12:focus-visible {
  box-shadow: var(--shadow-lg), 0 12px 28px var(--accent-glow);
}

.entry:hover::before,
.entry:focus-visible::before {
  opacity: 1;
}

.entry:focus-visible {
  outline: none;
}

.entry--gaokao:focus-visible {
  box-shadow: var(--shadow-lg), 0 0 0 3px rgba(254, 94, 3, 0.22);
}

.entry--k12:focus-visible {
  box-shadow: var(--shadow-lg), 0 0 0 3px rgba(31, 78, 163, 0.22);
}

.entry__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.entry__icon {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
}

.entry--gaokao .entry__icon {
  background: var(--brand-soft);
  color: var(--brand-500);
}

.entry--k12 .entry__icon {
  background: var(--accent-soft);
  color: var(--accent-500);
}

.entry__icon svg {
  width: 26px;
  height: 26px;
}

.entry__arrow {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--ink-50);
  color: var(--ink-400);
}

.entry__arrow svg {
  width: 18px;
  height: 18px;
}

.entry__title {
  margin: 0 0 8px;
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--ink-900);
  line-height: 1.3;
}

.entry__desc {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--ink-500);
  line-height: 1.6;
}

.entry__badge {
  display: inline-flex;
  align-items: center;
  margin-top: 16px;
  padding: 4px 10px;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  border-radius: 999px;
}

.entry--gaokao .entry__badge {
  background: var(--brand-soft);
  color: var(--brand-600);
}

.entry--k12 .entry__badge {
  background: var(--accent-soft);
  color: var(--accent-600);
}

.footer {
  padding: 24px 20px 32px;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--ink-400);
}

.footer a {
  color: var(--ink-500);
  text-decoration: none;
}

.footer a:hover {
  color: var(--accent-500);
}

@media (prefers-reduced-motion: reduce) {
  .entry {
    transition: none;
  }

  .entry:hover,
  .entry:focus-visible {
    transform: none;
  }
}