/* ── Reinforcement Learning · cyberpunk cyan + neon green + robot purple ──── */
/*
 * Design goal: cyberpunk energy that stays EYE-SOOTHING.
 * - Light mode uses deep, desaturated tones (readable on white, low glare).
 * - Dark mode reserves the true neon glow (cyan/green/purple) where it belongs:
 *   luminous accents on a near-black slate. Classic cyberpunk, easy on the eyes.
 */

:root {
  /* Cyberpunk Cyan (primary / lead) */
  --rl-cyan: #0c93a8;
  --rl-cyan-deep: #076576;
  --rl-cyan-bright: #22d3ee;

  /* Neon Green (positive-reward accent) */
  --rl-green: #10b981;
  --rl-green-deep: #0a8f68;
  --rl-green-bright: #34e5a1;

  /* Robot Purple (secondary accent) */
  --rl-purple: #7c6cf0;
  --rl-purple-deep: #5b4bd6;
  --rl-purple-bright: #a78bfa;

  --rl-ink: #0b1220;
  --rl-border: rgba(11, 18, 32, 0.14);

  /* Drive Material's primary (header/nav/footer) and accent (links/hover).
     Deep cyan primary + deep green accent → calm and readable in light mode. */
  --md-primary-fg-color: #0c93a8;
  --md-primary-fg-color--light: #22d3ee;
  --md-primary-fg-color--dark: #076576;
  --md-accent-fg-color: #0a8f68;
}

[data-md-color-scheme="slate"] {
  --rl-border: rgba(120, 220, 255, 0.16);

  /* Cyberpunk night: deep blue-black surfaces so the neon reads as "glow". */
  --md-default-bg-color: #0b1220;
  --md-primary-fg-color: #0c93a8;
  --md-primary-fg-color--light: #22d3ee;
  --md-primary-fg-color--dark: #076576;

  /* On dark, links + hover get the true neon so the palette comes alive. */
  --md-accent-fg-color: #34e5a1;
  --md-typeset-a-color: #22d3ee;
}

/* ── Header / tabs: two-tone neon underline ───────────────────────────────── */
.md-header,
.md-tabs {
  box-shadow: none;
}

/* thin gradient hairline (cyan → green → purple) under the header/tabs */
.md-tabs {
  border-bottom: 3px solid transparent;
  border-image: linear-gradient(90deg, var(--rl-cyan-bright), var(--rl-green-bright), var(--rl-purple-bright)) 1;
}

.md-header__title {
  font-weight: 700;
}

/* ── Typography ───────────────────────────────────────────────────────────── */
.md-typeset h1,
.md-typeset h2 {
  font-weight: 750;
  letter-spacing: 0;
}

.md-typeset h1 {
  margin-bottom: 0.9rem;
  color: var(--rl-cyan-deep);
}

[data-md-color-scheme="slate"] .md-typeset h1 {
  color: var(--rl-cyan-bright);
}

.md-typeset h2 {
  border-bottom: 2px solid var(--rl-green);
  padding-bottom: 0.35rem;
}

[data-md-color-scheme="slate"] .md-typeset h2 {
  border-bottom-color: var(--rl-green-bright);
}

/* ── Tables ───────────────────────────────────────────────────────────────── */
.md-typeset table:not([class]) {
  border: 1px solid var(--rl-border);
  border-radius: 0.4rem;
  overflow: hidden;
}

.md-typeset table:not([class]) th {
  background: var(--rl-cyan-deep);
  color: #fff;
  font-weight: 700;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) th {
  background: linear-gradient(90deg, var(--rl-cyan-deep), var(--rl-purple-deep));
}

.md-typeset code {
  border-radius: 0.25rem;
}

.md-typeset .admonition,
.md-typeset details {
  border-radius: 0.45rem;
}

/* purple left rule on blockquotes — the "note from the agent" accent */
.md-typeset blockquote {
  border-left: 0.2rem solid var(--rl-purple);
}

[data-md-color-scheme="slate"] .md-typeset blockquote {
  border-left-color: var(--rl-purple-bright);
}

/* ── Home hero cards ──────────────────────────────────────────────────────── */
.rl-hero-grid {
  display: grid;
  gap: 0.8rem;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  margin: 1.5rem 0 2rem;
}

.md-typeset .rl-card {
  align-items: center;
  border: 1px solid var(--rl-border);
  border-left: 0.35rem solid var(--rl-cyan);
  border-radius: 0.5rem;
  color: var(--md-default-fg-color);
  display: flex;
  font-size: 1.05rem;
  font-weight: 700;
  gap: 0.55rem;
  min-height: 5rem;
  padding: 1rem;
  text-decoration: none;
  transition: border-color 150ms ease, box-shadow 150ms ease, transform 150ms ease;
}

.md-typeset .rl-card:hover {
  border-color: var(--rl-green);
  box-shadow: 0 0.55rem 1.4rem rgba(12, 147, 168, 0.22);
  transform: translateY(-2px);
}

[data-md-color-scheme="slate"] .md-typeset .rl-card:hover {
  box-shadow: 0 0 0.2rem var(--rl-cyan-bright), 0 0.55rem 1.4rem rgba(34, 211, 238, 0.25);
}

/* one accent color per section — cyan / green / purple cycle */
.md-typeset .rl-card-notes {
  border-left-color: var(--rl-cyan);
}
.md-typeset .rl-card-exercises {
  border-left-color: var(--rl-green);
}
.md-typeset .rl-card-projects {
  border-left-color: var(--rl-purple);
}
.md-typeset .rl-card-resources {
  border-left-color: var(--rl-cyan-deep);
}

.md-nav__item .md-nav__link--active {
  font-weight: 700;
}

.md-footer {
  margin-top: 2rem;
}

@media screen and (max-width: 44.9375em) {
  .rl-hero-grid {
    grid-template-columns: 1fr;
  }

  .md-typeset .rl-card {
    min-height: 4.25rem;
  }
}
/* Learning resource hub navigation: right rail */
.resource-sidebar-hub {
  border-top: 1px solid var(--md-default-fg-color--lightest);
  display: flex;
  flex-direction: column;
  gap: 0.42rem;
  margin-top: 1rem;
  padding-top: 0.85rem;
}

.resource-sidebar-hub__title {
  color: var(--md-default-fg-color--light);
  font-size: 0.64rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 1.2;
  margin-bottom: 0.1rem;
  text-transform: uppercase;
}

.resource-sidebar-hub__button {
  align-items: center;
  border: 1px solid var(--course-hub-color, var(--md-primary-fg-color));
  border-radius: 0.45rem;
  color: var(--course-hub-color, var(--md-primary-fg-color));
  display: flex;
  font-size: 0.68rem;
  font-weight: 800;
  justify-content: space-between;
  line-height: 1.25;
  padding: 0.42rem 0.5rem;
  text-decoration: none;
  transition: background-color 150ms ease, box-shadow 150ms ease, transform 150ms ease;
}

.resource-sidebar-hub__button::after {
  content: "\2192";
  flex-shrink: 0;
  font-weight: 900;
  margin-left: 0.45rem;
}

.resource-sidebar-hub__button:hover {
  background-color: color-mix(in srgb, var(--course-hub-color, var(--md-primary-fg-color)) 10%, transparent);
  box-shadow: 0 0.25rem 0.65rem color-mix(in srgb, var(--course-hub-color, var(--md-primary-fg-color)) 15%, transparent);
  text-decoration: none;
  transform: translateY(-1px);
}

.resource-sidebar-hub__home { --course-hub-color: var(--md-primary-fg-color); }
.resource-sidebar-hub__dsai { --course-hub-color: #34526b; }
.resource-sidebar-hub__cyber { --course-hub-color: #b4122e; }