:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-2: #f0f4f8;
  --line: rgba(24, 39, 56, 0.12);
  --text: #15202b;
  --muted: #5f7183;
  --accent: #2fa36f;
  --accent-soft: rgba(47, 163, 111, 0.12);
  --radius: 10px;
  --radius-sm: 8px;
  --max: 1040px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1316;
    --surface: #171d22;
    --surface-2: #1e262d;
    --line: rgba(255,255,255,0.08);
    --text: #eef3f5;
    --muted: #9fb0ba;
    --accent: #3ed29f;
    --accent-soft: rgba(62, 210, 159, 0.12);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: linear-gradient(180deg, var(--bg) 0%, color-mix(in srgb, var(--bg) 88%, #dfe7ef 12%) 100%);
}

a { color: inherit; text-decoration: none; }
input, button { font: inherit; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  background: var(--accent);
  color: white;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  z-index: 20;
}
.skip-link:focus { top: 16px; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.container {
  width: min(calc(100% - 32px), var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 12;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px);
  transition: transform 0.24s ease, background 0.2s ease, border-color 0.2s ease;
  will-change: transform;
}

.site-header.is-hidden {
  transform: translateY(calc(-100% - 1px));
}

.site-header.menu-open {
  transform: translateY(0);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 16px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
  flex: 0 0 auto;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: white;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: 8px;
}

.desktop-nav a,
.mobile-nav a,
.back-top-floating {
  color: var(--muted);
  padding: 8px 10px;
  border-radius: var(--radius-sm);
}

.desktop-nav a:hover,
.desktop-nav a:focus-visible,
.mobile-nav a:hover,
.mobile-nav a:focus-visible,
.back-top-floating:hover,
.back-top-floating:focus-visible {
  color: var(--text);
  background: color-mix(in srgb, var(--surface-2) 88%, transparent);
}

.desktop-search {
  margin-left: auto;
}

.desktop-search input {
  width: min(260px, 30vw);
  height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-2) 70%, transparent);
  color: var(--text);
}

.desktop-search input::placeholder,
.mobile-search input::placeholder {
  color: var(--muted);
}

.desktop-search input:focus,
.mobile-search input:focus {
  outline: none;
  border-color: color-mix(in srgb, var(--accent) 55%, var(--line));
  background: var(--surface);
}

.mobile-search {
  display: none;
}

.mobile-search input {
  width: 100%;
  height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-2) 70%, transparent);
  color: var(--text);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-2) 60%, transparent);
  color: var(--text);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0 auto;
  border-radius: 999px;
  background: currentColor;
  transition: transform 0.24s ease, opacity 0.18s ease;
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.menu-toggle:hover,
.menu-toggle:focus-visible {
  background: color-mix(in srgb, var(--surface-2) 88%, transparent);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--line));
}

.mobile-menu-shell {
  display: none;
}

.mobile-menu {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transform: translateY(-8px);
  transition: max-height 0.28s ease, opacity 0.22s ease, transform 0.22s ease;
}

.mobile-menu.is-open {
  max-height: 240px;
  opacity: 1;
  transform: translateY(0);
}

.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 10px 0 12px;
}

.hero {
  padding: 34px 0 14px;
}

.hero-inner {
  max-width: var(--max);
  margin-inline: auto;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 10px;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.hero h1,
.section-head h2,
.about-box h2,
.card-body h3 {
  margin: 0;
  letter-spacing: -0.03em;
  text-align: left;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1.1;
  max-width: 12ch;
}

.lead,
.section-head p,
.category-card span:last-child,
.card-body p,
.about-box p,
.meta {
  color: var(--muted);
}

.lead {
  margin: 14px 0 0;
  max-width: 62ch;
  text-align: left;
}

.section {
  padding: 28px 0 20px;
}

.section-head {
  margin-bottom: 16px;
}

.section-head h2,
.about-box h2 {
  font-size: clamp(1.35rem, 2.5vw, 2rem);
  margin-bottom: 6px;
}

.category-grid,
.card-grid {
  display: grid;
  gap: 14px;
}

.category-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.category-card,
.resource-card,
.about-box {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.04);
}

@media (prefers-color-scheme: dark) {
  .category-card,
  .resource-card,
  .about-box {
    box-shadow: none;
  }
}

.category-card {
  display: block;
  position: relative;
  padding: 20px 18px 18px;
  min-height: 128px;
}

.category-emoji {
  display: block;
  margin-bottom: 12px;
  font-size: 1.2rem;
  line-height: 1;
}

.category-card strong,
.card-body h3 {
  display: block;
  margin-bottom: 6px;
}

a.category-card:hover,
a.category-card:focus-visible,
.resource-card:hover {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
  background: color-mix(in srgb, var(--surface) 82%, var(--surface-2));
}

.category-card.is-soon {
  cursor: default;
}

.resource-card {
  padding: 0;
  overflow: hidden;
}

.card-body {
  padding: 18px 18px 14px;
}

.card-head {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  margin-bottom: 12px;
}

.badge,
.mini-link {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border-radius: var(--radius-sm);
  font-size: 0.84rem;
  font-weight: 700;
}

.badge {
  background: var(--accent-soft);
  color: var(--accent);
}

.sub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0 18px 18px;
}

.mini-link {
  border: 1px solid var(--line);
  color: var(--text);
  background: color-mix(in srgb, var(--surface-2) 72%, transparent);
}

.mini-link:hover,
.mini-link:focus-visible {
  background: color-mix(in srgb, var(--surface-2) 100%, transparent);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--line));
}

.muted-section {
  padding-bottom: 40px;
}

.about-box {
  padding: 20px;
}

.back-top-floating {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 10;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(10px);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, background 0.2s ease;
}

.back-top-floating.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.category-card {
  position: relative;
  display: block;
  padding: 20px 18px 18px;
  min-height: 128px;
}

.category-emoji {
  display: block;
  margin-bottom: 12px;
  font-size: 1.2rem;
  line-height: 1;
}

.category-meta {
  position: absolute;
  top: 20px;
  right: 18px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
}

.category-card strong {
  display: block;
  margin-bottom: 6px;
}

@media (max-width: 920px) {
  .category-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .desktop-search input { width: 200px; }
}

@media (max-width: 640px) {
  .desktop-nav,
  .desktop-search {
    display: none;
  }

  .mobile-search {
    display: block;
    padding-top: 4px;
  }

  .menu-toggle,
  .mobile-menu-shell {
    display: block;
  }

  .menu-toggle {
    display: inline-flex;
  }

  .category-grid,
  .card-grid {
    grid-template-columns: 1fr;
  }

  .card-head {
    flex-wrap: wrap;
    align-items: flex-start;
  }

  .hero h1 {
    max-width: 100%;
  }

  .back-top-floating {
    right: 12px;
    bottom: 12px;
    font-size: 0.92rem;
  }
}