/* ============================================================
   NetLearn Directory — design system
   Complementary palette: deep teal (primary) + warm coral (accent)
   ============================================================ */

:root {
  --bg: #f4f8f8;
  --surface: #ffffff;
  --surface-2: #eaf1f1;
  --border: #d8e2e2;
  --text: #17282b;
  --text-muted: #52686c;

  --primary: #0e7c86;
  --primary-strong: #0a626a;
  --primary-soft: #d9eef0;
  --on-primary: #ffffff;

  --accent: #e8603c;
  --accent-strong: #cf4b28;
  --accent-soft: #fde7df;
  --on-accent: #ffffff;

  --beginner-bg: #ddf2e4;   --beginner-fg: #1d6b3c;
  --intermediate-bg: #fdeecf; --intermediate-fg: #8a5a06;
  --advanced-bg: #f4dff2;   --advanced-fg: #8b2f80;

  --shadow: 0 1px 3px rgba(23, 40, 43, 0.08), 0 4px 16px rgba(23, 40, 43, 0.06);
  --shadow-lift: 0 4px 10px rgba(23, 40, 43, 0.10), 0 12px 28px rgba(23, 40, 43, 0.10);
  --radius: 14px;
  --radius-sm: 8px;
  --header-h: 60px;
}

[data-theme="dark"] {
  --bg: #101b1f;
  --surface: #18262b;
  --surface-2: #1f3138;
  --border: #2c424a;
  --text: #e6eef0;
  --text-muted: #93a8ad;

  --primary: #3fb9c4;
  --primary-strong: #63cdd6;
  --primary-soft: #143a40;
  --on-primary: #08262a;

  --accent: #f0805e;
  --accent-strong: #f5977a;
  --accent-soft: #46271d;
  --on-accent: #2b1108;

  --beginner-bg: #17362a;   --beginner-fg: #6fd39a;
  --intermediate-bg: #3c2f12; --intermediate-fg: #eec06a;
  --advanced-bg: #3a1f38;   --advanced-fg: #dd8ed4;

  --shadow: 0 1px 3px rgba(0, 0, 0, 0.35), 0 4px 16px rgba(0, 0, 0, 0.28);
  --shadow-lift: 0 4px 10px rgba(0, 0, 0, 0.4), 0 12px 28px rgba(0, 0, 0, 0.38);
}

* { box-sizing: border-box; }

.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;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

a { color: var(--primary); }

button { font: inherit; color: inherit; }

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--header-h);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--primary);
  color: var(--on-primary);
}

.brand-accent { color: var(--accent); }

.theme-toggle {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.15s ease;
}

.theme-toggle:hover { background: var(--surface-2); transform: scale(1.06); }

[data-theme="light"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }

/* ---------- Hero ---------- */

.hero {
  padding: 56px 0 40px;
  text-align: center;
  background:
    radial-gradient(720px 340px at 15% 0%, color-mix(in srgb, var(--primary) 14%, transparent), transparent 70%),
    radial-gradient(720px 340px at 85% 0%, color-mix(in srgb, var(--accent) 12%, transparent), transparent 70%);
}

.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(1.8rem, 4.5vw, 2.9rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-accent { color: var(--accent); }

.hero-sub {
  max-width: 640px;
  margin: 0 auto 14px;
  color: var(--text-muted);
  font-size: 1.06rem;
}

.hero-count {
  margin: 0;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--primary);
}

/* ---------- Controls bar ---------- */

.controls-bar {
  position: sticky;
  top: var(--header-h);
  z-index: 30;
  padding: 12px 0;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.controls-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.search-box {
  flex: 1 1 260px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 14px;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-muted);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-box:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 22%, transparent);
}

.search-box input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  color: var(--text);
  font: inherit;
  min-width: 0;
}

.sort-box {
  display: flex;
  align-items: center;
  gap: 8px;
}

.sort-label {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 600;
}

.sort-box select {
  height: 44px;
  padding: 0 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}

.filters-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 44px;
  padding: 0 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
  font-weight: 600;
}

.filters-toggle[aria-expanded="true"] {
  border-color: var(--primary);
  color: var(--primary);
}

.filters-count[hidden] { display: none; }

.filters-count {
  display: inline-grid;
  place-items: center;
  min-width: 20px;
  height: 20px;
  padding: 0 5px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--on-accent);
  font-size: 0.75rem;
  font-weight: 700;
}

.active-filters {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: 10px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--text);
  font-size: 0.83rem;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.chip:hover { background: var(--accent-soft); }

.chip .chip-x { font-weight: 700; color: var(--accent-strong); }

.chip-clear {
  background: transparent;
  border: none;
  color: var(--accent-strong);
  font-size: 0.83rem;
  font-weight: 700;
  cursor: pointer;
  text-decoration: underline;
  padding: 4px 6px;
}

/* ---------- Filter panel ---------- */

.filter-panel {
  padding: 18px 0 6px;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}

.filter-panel[hidden] { display: none; }

.filter-group { margin-bottom: 14px; }

.filter-heading {
  margin: 0 0 8px;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pill {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-size: 0.88rem;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.1s ease;
}

.pill:hover { border-color: var(--primary); transform: translateY(-1px); }

.pill[aria-pressed="true"] {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--on-primary);
  font-weight: 600;
}

/* ---------- Results / grid ---------- */

main { padding: 26px 20px 60px; }

.results-summary {
  margin: 0 0 18px;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

/* ---------- Card ---------- */

.card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.card-category {
  font-size: 0.76rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--primary);
}

.badge {
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 700;
  white-space: nowrap;
}

.badge-beginner { background: var(--beginner-bg); color: var(--beginner-fg); }
.badge-intermediate { background: var(--intermediate-bg); color: var(--intermediate-fg); }
.badge-advanced { background: var(--advanced-bg); color: var(--advanced-fg); }

.card-title {
  margin: 0;
  font-size: 1.12rem;
  line-height: 1.3;
}

.card-title a {
  color: var(--text);
  text-decoration: none;
}

.card-title a:hover { color: var(--primary); text-decoration: underline; }

.card-type {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.83rem;
  font-weight: 600;
}

.card-desc {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.93rem;
  flex-grow: 1;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  padding: 3px 10px;
  border: none;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.tag:hover { background: var(--primary-soft); color: var(--primary); }

.tag[aria-pressed="true"] { background: var(--primary); color: var(--on-primary); }

.card-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding-top: 4px;
  border-top: 1px solid var(--border);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 16px;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.15s ease, transform 0.1s ease;
}

.btn-primary { background: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-strong); transform: translateY(-1px); }

.share-wrap { position: relative; }

.btn-share {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-share:hover { border-color: var(--primary); color: var(--primary); }

/* ---------- Share popover ---------- */

.share-popover {
  position: absolute;
  right: 0;
  bottom: calc(100% + 8px);
  z-index: 20;
  min-width: 190px;
  padding: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lift);
}

.share-popover a,
.share-popover button {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 10px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text);
  font-size: 0.88rem;
  font-weight: 600;
  text-align: left;
  text-decoration: none;
  cursor: pointer;
}

.share-popover a:hover,
.share-popover button:hover { background: var(--surface-2); }

.share-popover svg { flex-shrink: 0; }

/* ---------- Empty state ---------- */

.empty-state {
  padding: 70px 20px;
  text-align: center;
}

.empty-art { font-size: 3rem; margin-bottom: 10px; }

.empty-state h2 { margin: 0 0 6px; }

.empty-state p { color: var(--text-muted); margin: 0 0 18px; }

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface-2);
  padding: 30px 0;
}

.footer-inner {
  color: var(--text-muted);
  font-size: 0.92rem;
  max-width: 720px;
  text-align: center;
}

.footer-inner p { margin: 0 0 8px; }

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  z-index: 60;
  padding: 10px 20px;
  background: var(--text);
  color: var(--bg);
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  box-shadow: var(--shadow-lift);
  animation: toast-in 0.2s ease;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(-50%) translateY(8px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ---------- Responsive ---------- */

@media (max-width: 640px) {
  .hero { padding: 40px 0 28px; }
  .sort-label { display: none; }
  .card-grid { grid-template-columns: 1fr; }
  .controls-inner { gap: 8px; }
  .filters-toggle { padding: 0 12px; }
}

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