/* ===== Variables ===== */
:root {
  --bg: #0d0d0f;
  --bg-elevated: #16161a;
  --bg-card: #1a1a1f;
  --border: #2a2a32;
  --text: #e4e4e7;
  --text-muted: #a1a1aa;
  --accent: #f59e0b;
  --accent-dim: rgba(245, 158, 11, 0.15);
  --accent-hover: #fbbf24;
  --success: #22c55e;
  --font-sans: 'DM Sans', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

/* ===== Header ===== */
.header {
  background: linear-gradient(180deg, var(--bg-elevated) 0%, var(--bg) 100%);
  padding: 2.5rem 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 720px;
  margin: 0 auto;
}

.logo {
  margin: 0 0 0.25rem;
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 0 0 1.5rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.search-wrap {
  position: relative;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 2.5rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--text);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 1rem;
  pointer-events: none;
}

/* ===== Nav ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(13, 13, 15, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0.5rem 1.5rem;
  display: flex;
  gap: 0.25rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-inner::-webkit-scrollbar {
  display: none;
}

.nav-btn {
  flex-shrink: 0;
  padding: 0.5rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: color 0.2s, background 0.2s;
}

.nav-btn:hover {
  color: var(--text);
  background: var(--bg-card);
}

.nav-btn.active {
  color: var(--accent);
  background: var(--accent-dim);
}

/* ===== Main ===== */
.main {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.content {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

/* ===== Section ===== */
.section {
  scroll-margin-top: 4rem;
}

.section-header {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.section-emoji {
  font-size: 1.25rem;
}

.section-title {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.section-desc {
  margin: 0 0 1.5rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* ===== Category ===== */
.category {
  margin-bottom: 1.5rem;
}

.category:last-child {
  margin-bottom: 0;
}

.category-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-muted);
}

.category-emoji {
  font-size: 1rem;
}

/* ===== Card ===== */
.card-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.card {
  display: block;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, background 0.2s, transform 0.15s;
}

.card:hover {
  border-color: var(--accent);
  background: var(--bg-elevated);
}

.card.hidden {
  display: none;
}

.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.35rem;
}

.card-num {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
}

.card-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

.card-desc {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-top: 0.5rem;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--accent);
  text-decoration: none;
  opacity: 0.9;
}

.card-link:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* ===== Resources ===== */
.resources-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.resource-link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius);
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s;
}

.resource-link:hover {
  background: rgba(245, 158, 11, 0.25);
  border-color: var(--accent);
}

/* ===== No results ===== */
.no-results {
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--text-muted);
}

.no-results p {
  margin: 0 0 0.5rem;
}

.no-results-hint {
  font-size: 0.9rem;
  opacity: 0.8;
}

/* ===== Footer ===== */
.footer {
  padding: 2rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--border);
}

.footer p {
  margin: 0;
}

/* ===== Highlight ===== */
mark {
  background: var(--accent-dim);
  color: var(--accent);
  padding: 0 2px;
  border-radius: 2px;
}