:root {
  --bg: #0f1024;
  --bg-alt: #171838;
  --card-bg: #1f2147;
  --text: #f4f4fb;
  --text-dim: #b9baD6;
  --accent: #7c5cfc;
  --accent-2: #4ecdc4;
  --star: #ffd166;
  --star-off: #3c3d63;
  --radius: 18px;
  --max-width: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(circle at 20% -10%, #2a2465 0%, var(--bg) 45%) fixed;
  color: var(--text);
  line-height: 1.5;
}

a { color: inherit; }

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

.site-header {
  padding: 72px 0 48px;
  text-align: center;
}

.site-header .kicker {
  display: inline-block;
  background: linear-gradient(90deg, var(--accent), #f857a6);
  color: #fff;
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 999px;
  margin-bottom: 20px;
}

.site-header h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  margin: 0 0 16px;
  background: linear-gradient(90deg, #fff, #b9baff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.site-header p {
  color: var(--text-dim);
  max-width: 640px;
  margin: 0 auto;
  font-size: 1.05rem;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  margin-top: 32px;
}

.legend a {
  text-decoration: none;
  background: var(--card-bg);
  border: 1px solid rgba(255,255,255,0.08);
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--text-dim);
  transition: transform 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.legend a:hover {
  transform: translateY(-2px);
  color: var(--text);
  border-color: var(--accent-2);
}

/* ---------- Difficulty sections ---------- */

.tier {
  padding: 56px 0 8px;
  scroll-margin-top: 24px;
}

.tier-heading {
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 28px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  padding-bottom: 16px;
}

.tier-heading h2 {
  font-size: 1.5rem;
  margin: 0;
}

.tier-heading .stars {
  font-size: 1.3rem;
  letter-spacing: 2px;
}

.tier-heading .tier-desc {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin: 0;
  flex-basis: 100%;
}

.stars .on, .card-stars .on { color: var(--star); }
.stars .off, .card-stars .off { color: var(--star-off); }

/* ---------- Cards ---------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
  margin-bottom: 16px;
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.06);
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.35);
}

.card-media {
  aspect-ratio: 4 / 3;
  width: 100%;
  display: block;
}

.card-media img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.card-body {
  padding: 20px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

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

.card-title-row h3 {
  margin: 0;
  font-size: 1.15rem;
}

.card-stars {
  white-space: nowrap;
  font-size: 0.95rem;
  flex-shrink: 0;
}

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

.tag {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: rgba(124,92,252,0.18);
  color: #c9beff;
  padding: 4px 10px;
  border-radius: 999px;
  font-weight: 600;
}

.card-desc {
  color: var(--text-dim);
  font-size: 0.94rem;
  margin: 0;
  flex: 1;
}

.card-cta {
  margin-top: 6px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  background: linear-gradient(90deg, var(--accent), #a78bfa);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: 999px;
  font-size: 0.92rem;
  transition: filter 0.15s ease;
}

.card-cta:hover { filter: brightness(1.12); }

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

.site-footer {
  margin-top: 80px;
  padding: 32px 0 60px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
  border-top: 1px solid rgba(255,255,255,0.08);
}

@media (max-width: 480px) {
  .site-header { padding: 48px 0 32px; }
}