/* ============================================================
   Knowledge Hub — styles.css
   ============================================================ */

/* --- Tokens --- */
:root {
  --bg: #0c0d0f;
  --panel: #111214;
  --panel2: #15171a;
  --text: #f5f6f7;
  --dim: #9aa3b2;
  --muted: #6b7280;
  --border: #2a2a2a;
  --line: #1e1e1e;
  --accent: #a78bfa;
  --accent2: #c4b5fd;
  --shadow: rgba(0, 0, 0, 0.35);
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  --sans: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
}

/* --- Reset / Base --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
}

html {
  scroll-behavior: smooth;
  scrollbar-gutter: stable both-edges;
  overflow-y: scroll;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

/* --- Skip Link --- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--bg);
  padding: 0.5rem 1rem;
  z-index: 100;
  border-radius: 0 0 4px 0;
  font-weight: 600;
}

.skip-link:focus {
  left: 0;
}

/* --- Topbar / Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar {
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}

.topbar-content {
  max-width: 960px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--dim);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand:hover {
  color: var(--text);
}

/* --- Layout --- */
.wrap {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.25rem;
  width: 100%;
}

/* --- Intro --- */
.intro {
  text-align: center;
  padding: 4rem 0 3rem;
}

.intro-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.intro-subtitle {
  font-size: 1.05rem;
  color: var(--dim);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.65;
}

/* --- Sections Grid --- */
.sections-section {
  padding-bottom: 3rem;
}

.sections-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 960px) {
  .sections-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 720px) {
  .sections-grid {
    grid-template-columns: 1fr;
  }
}

/* --- Section Card --- */
.section-card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: border-color 0.25s ease, transform 0.25s ease,
    box-shadow 0.25s ease;
  cursor: pointer;
}

.section-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--shadow);
}

.section-card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* --- Section Visuals --- */
.section-visual {
  margin-bottom: 1.25rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  border-radius: 6px;
}

.section-icon {
  width: 48px;
  height: 48px;
  color: var(--accent);
}

/* --- Card Text --- */
.section-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.section-tagline {
  font-size: 0.9rem;
  color: var(--dim);
  line-height: 1.5;
  margin-bottom: 0.65rem;
}

.section-stats {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.01em;
}

/* --- Footer --- */
.fineprint {
  text-align: center;
  padding: 2rem 1.25rem;
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.fineprint a {
  color: var(--dim);
  transition: color 0.2s ease;
}

.fineprint a:hover {
  color: var(--text);
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .section-card {
    transition: none;
  }

  .section-card:hover {
    transform: none;
  }
}