/* =====================================================================
   Landing page — choose between Anthropic Engineering / Claude Blog.
   Neutral, minimal design with two prominent entry cards.
   ===================================================================== */

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background: #faf9f5;
  color: #141413;
  font-family:
    "Inter", "Noto Sans JP", "Yu Gothic", "YuGothic", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", -apple-system, system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "palt" 1;
  text-rendering: optimizeLegibility;
}

:root {
  --l-bg: #faf9f5;
  --l-bg-soft: #f4f0e8;
  --l-text: #141413;
  --l-text-muted: #5a5a58;
  --l-text-subtle: #8a8a85;
  --l-rule: #e6e3d9;

  --l-anthropic: #c9681f;      /* warm serif blog accent */
  --l-anthropic-dark: #8a4a14;
  --l-claude: #cc785c;          /* Claude blog orange */
  --l-claude-dark: #a85a3e;

  --l-shadow-card: 0 2px 4px rgba(24, 20, 10, 0.05), 0 14px 40px rgba(24, 20, 10, 0.08);
  --l-shadow-card-hover: 0 4px 12px rgba(24, 20, 10, 0.1), 0 28px 60px rgba(24, 20, 10, 0.14);
}

a { color: inherit; }

.l-container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 28px;
}

.l-main {
  padding-top: 64px;
  padding-bottom: 120px;
}

/* ---- Header -------------------------------------------------------- */
.l-header {
  background: transparent;
  padding: 24px 0;
  border-bottom: 1px solid var(--l-rule);
}
.l-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.l-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--l-text);
  text-decoration: none;
  font-weight: 700;
  font-size: 16px;
}
.l-brand-glyph {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1.5px solid var(--l-text);
  border-radius: 4px;
  font-size: 15px;
}
.l-nav { display: flex; gap: 22px; }
.l-nav a {
  color: var(--l-text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 140ms ease;
}
.l-nav a:hover { color: var(--l-text); }

/* ---- Hero ---------------------------------------------------------- */
.l-hero {
  padding: 56px 0 64px;
  max-width: 820px;
}
.l-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--l-text-muted);
  text-transform: uppercase;
  margin-bottom: 20px;
}
.l-title {
  font-size: clamp(36px, 6vw, 68px);
  line-height: 1.08;
  letter-spacing: -0.025em;
  font-weight: 700;
  margin: 0 0 24px;
  color: var(--l-text);
}
.l-lead {
  font-size: 19px;
  line-height: 1.65;
  color: var(--l-text-muted);
  max-width: 700px;
  margin: 0;
}

/* ---- Cards --------------------------------------------------------- */
.l-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
  gap: 28px;
  margin: 32px 0 64px;
}
.l-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  background: #ffffff;
  border: 1px solid var(--l-rule);
  border-radius: 16px;
  padding: 40px 40px 36px;
  box-shadow: var(--l-shadow-card);
  transition: transform 220ms ease, box-shadow 220ms ease, border-color 220ms ease;
  position: relative;
  overflow: hidden;
}
.l-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 6px;
}
.l-card--anthropic::before {
  background: linear-gradient(90deg, var(--l-anthropic) 0%, var(--l-anthropic-dark) 100%);
}
.l-card--claude::before {
  background: linear-gradient(90deg, var(--l-claude) 0%, var(--l-claude-dark) 100%);
}
.l-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--l-shadow-card-hover);
}
.l-card--anthropic:hover { border-color: var(--l-anthropic); }
.l-card--claude:hover { border-color: var(--l-claude); }

.l-card-badge {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.l-card--anthropic .l-card-badge { color: var(--l-anthropic); }
.l-card--claude .l-card-badge { color: var(--l-claude); }

.l-card-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 8px;
  color: var(--l-text);
}
.l-card--anthropic .l-card-title {
  font-family: "Source Serif 4", "Noto Serif JP", "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-weight: 600;
}
.l-card-subtitle {
  font-size: 15px;
  color: var(--l-text-muted);
  font-weight: 500;
  margin: 0 0 20px;
}
.l-card-desc {
  font-size: 15px;
  line-height: 1.7;
  color: #4a4a47;
  margin: 0 0 28px;
  flex: 1;
}
.l-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 20px;
  border-top: 1px solid var(--l-rule);
  font-size: 14px;
  color: var(--l-text-muted);
}
.l-card-meta strong {
  color: var(--l-text);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.l-card-arrow {
  font-weight: 600;
}
.l-card--anthropic .l-card-arrow { color: var(--l-anthropic); }
.l-card--claude .l-card-arrow { color: var(--l-claude); }

/* ---- Note ---------------------------------------------------------- */
.l-note {
  max-width: 820px;
  padding: 24px 28px;
  background: var(--l-bg-soft);
  border-left: 3px solid var(--l-text-subtle);
  border-radius: 0 8px 8px 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--l-text-muted);
}
.l-note p { margin: 0; }
.l-note a {
  color: var(--l-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}
.l-note a:hover { color: var(--l-anthropic-dark); }

/* ---- Footer -------------------------------------------------------- */
.l-footer {
  border-top: 1px solid var(--l-rule);
  padding: 48px 0 64px;
  background: var(--l-bg-soft);
  margin-top: 80px;
}
.l-footer-inner {
  font-size: 14px;
  color: var(--l-text-muted);
}
.l-footer-note {
  line-height: 1.7;
  margin: 0 0 16px;
  max-width: 680px;
}
.l-footer-links {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}
.l-footer-links a {
  color: var(--l-text-muted);
  text-decoration: none;
}
.l-footer-links a:hover { color: var(--l-text); }
.l-footer-links span { color: var(--l-text-subtle); }

/* ---- Responsive ---------------------------------------------------- */
@media (max-width: 820px) {
  .l-container { padding: 0 20px; }
  .l-main { padding-top: 40px; }

  .l-hero { padding: 36px 0 40px; }
  .l-title { font-size: 34px; }
  .l-lead { font-size: 16px; }

  .l-cards {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .l-card { padding: 32px 28px 28px; }
  .l-card-title { font-size: 26px; }
}