/* Course pages — portfolio design system (dark theme) */

@import url("https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700&family=Fraunces:ital,opsz,wght@0,9..144,500;0,9..144,600;0,9..144,700&display=swap");

:root {
  --bg: #0f1419;
  --bg-elevated: #1a222d;
  --surface: #232d3b;
  --text: #e8eef4;
  --text-muted: #8fa3b8;
  --accent: #3d9cfd;
  --accent-hover: #5aadff;
  --accent-soft: rgba(61, 156, 253, 0.15);
  --accent-2: #7c5cff;
  --border: rgba(255, 255, 255, 0.08);
  --code-bg: #121820;
  --code-text: #e2e8f0;
  --note-bg: rgba(61, 156, 253, 0.1);
  --note-border: #3d9cfd;
  --warning-bg: rgba(245, 158, 11, 0.12);
  --warning-border: #f59e0b;
  --tip-bg: rgba(34, 197, 94, 0.1);
  --tip-border: #22c55e;
  --example-bg: rgba(124, 92, 255, 0.1);
  --example-border: #7c5cff;
  --font-sans: "DM Sans", system-ui, sans-serif;
  --font-display: "Fraunces", Georgia, serif;
  --radius: 12px;
  --header-height: 56px;
  --sidebar-width: 280px;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body.course-page {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ── DSA course layout ── */
body.course-page > header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(15, 20, 25, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 90;
}

body.course-page > header h1 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

body.course-page > header .subtitle {
  color: var(--accent);
}

body.course-page .layout {
  padding-top: var(--header-height);
  min-height: 100vh;
}

body.course-page .layout > nav {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-elevated);
  border-right: 1px solid var(--border);
}

body.course-page .layout > nav h2 {
  color: var(--text-muted);
}

body.course-page .layout > nav a {
  color: var(--text-muted);
}

body.course-page .layout > nav a:hover,
body.course-page .layout > nav a.active {
  color: var(--accent);
  background: var(--accent-soft);
}

body.course-page .layout > main {
  background: var(--bg);
  max-width: none;
}

body.course-page section {
  border-bottom-color: var(--border);
}

body.course-page section h2 {
  font-family: var(--font-display);
  color: var(--text);
}

body.course-page footer {
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  color: var(--text-muted);
}

/* ── AI course layout ── */
body.course-page .container {
  min-height: 100vh;
  overflow: visible;
}

body.course-page .container > .sidebar {
  width: var(--sidebar-width);
  background: var(--bg-elevated) !important;
  border-right: 1px solid var(--border) !important;
  padding: 1.25rem 1rem 2rem !important;
}

body.course-page .container > .sidebar h1 {
  font-family: var(--font-display);
  font-size: 1.15rem !important;
  font-weight: 600;
  color: var(--text) !important;
  border-bottom: 2px solid var(--accent) !important;
}

body.course-page .container > .sidebar h2 {
  color: var(--text-muted) !important;
  border-bottom-color: var(--border) !important;
  font-size: 0.8rem !important;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

body.course-page .container > .sidebar a {
  color: var(--text-muted) !important;
  font-size: 0.85rem !important;
  padding: 0.35rem 0.5rem !important;
  border-radius: 6px;
}

body.course-page .container > .sidebar a:hover {
  background: var(--accent-soft) !important;
  color: var(--accent) !important;
}

body.course-page .container > .sidebar a.active {
  background: var(--accent-soft) !important;
  color: var(--accent) !important;
  font-weight: 600;
}

body.course-page .container > .content {
  margin-left: var(--sidebar-width) !important;
  max-width: none !important;
  background: var(--bg);
  height: auto !important;
  min-height: 100vh;
  overflow: visible !important;
  padding: 1.75rem clamp(1rem, 4vw, 2.5rem) 4rem !important;
  box-sizing: border-box;
}

body.course-page .content h2[id],
body.course-page .content h3[id],
body.course-page .content h4[id] {
  scroll-margin-top: 4rem;
}

/* ── Shared typography & content ── */
body.course-page h1,
body.course-page h2,
body.course-page h3,
body.course-page h4 {
  color: var(--text);
}

body.course-page p,
body.course-page li {
  color: var(--text-muted);
}

body.course-page strong {
  color: var(--text);
}

body.course-page p code,
body.course-page li code,
body.course-page .content code {
  background: var(--surface) !important;
  color: var(--accent) !important;
  border: 1px solid var(--border);
}

body.course-page pre,
body.course-page .content pre {
  background: var(--code-bg) !important;
  color: var(--code-text) !important;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  -webkit-overflow-scrolling: touch;
}

body.course-page pre code,
body.course-page .content pre code {
  color: inherit !important;
  background: none !important;
  border: none;
}

/* Callout boxes */
body.course-page .note {
  background: var(--note-bg) !important;
  border-color: var(--note-border) !important;
}
body.course-page .note .box-title { color: var(--accent) !important; }

body.course-page .warning {
  background: var(--warning-bg) !important;
  border-color: var(--warning-border) !important;
}
body.course-page .warning .box-title { color: #fbbf24 !important; }

body.course-page .tip {
  background: var(--tip-bg) !important;
  border-color: var(--tip-border) !important;
}
body.course-page .tip .box-title { color: #4ade80 !important; }

body.course-page .example {
  background: var(--example-bg) !important;
  border-color: var(--example-border) !important;
}
body.course-page .example .box-title { color: var(--accent-2) !important; }

body.course-page .optimization {
  background: rgba(245, 158, 11, 0.1) !important;
  border-color: #d97706 !important;
}
body.course-page .optimization .box-title { color: #fbbf24 !important; }

body.course-page .interview-tip {
  background: rgba(124, 92, 255, 0.1) !important;
  border-color: var(--accent-2) !important;
}
body.course-page .interview-tip .box-title { color: var(--accent-2) !important; }

body.course-page .box {
  border-radius: var(--radius);
}

/* Tables */
body.course-page table,
body.course-page .content table {
  border-collapse: collapse;
  width: 100%;
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

body.course-page th,
body.course-page .content th {
  background: var(--surface) !important;
  color: var(--text) !important;
  border-color: var(--border) !important;
}

body.course-page td,
body.course-page .content td {
  border-color: var(--border) !important;
  color: var(--text-muted);
}

body.course-page tr:nth-child(even),
body.course-page .content tr:nth-child(even) {
  background: var(--bg-elevated) !important;
}

body.course-page hr,
body.course-page .content hr {
  border-top-color: var(--border) !important;
}

/* Scrollbars */
body.course-page ::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

body.course-page ::-webkit-scrollbar-track {
  background: var(--bg);
}

body.course-page ::-webkit-scrollbar-thumb {
  background: var(--surface);
  border-radius: 4px;
}

body.course-page ::-webkit-scrollbar-thumb:hover {
  background: #2f3b4d;
}

/* Images & media */
body.course-page img,
body.course-page svg,
body.course-page video,
body.course-page iframe {
  max-width: 100%;
  height: auto;
}

/* ── Mobile course top bar (injected by JS) ── */
.course-topbar {
  display: none;
}

@media (max-width: 768px) {
  :root {
    --header-height: 52px;
  }

  .course-topbar {
    display: flex !important;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    padding: 0 0.75rem;
    background: rgba(15, 20, 25, 0.98);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 5000;
  }

  .course-topbar-back {
    flex-shrink: 0;
    padding: 0.45rem 0.75rem;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--accent-soft);
    border: 1px solid rgba(61, 156, 253, 0.3);
    border-radius: 999px;
    text-decoration: none;
  }

  .course-topbar-back:hover {
    color: var(--text);
    background: var(--accent);
    text-decoration: none;
  }

  .course-topbar-title {
    flex: 1;
    min-width: 0;
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .course-topbar-menu {
    flex-shrink: 0;
    padding: 0.45rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
  }

  .course-topbar-menu[aria-expanded="true"] {
    background: var(--accent);
    border-color: var(--accent);
    color: #0f1419;
  }

  /* Hide course title header only — not the mobile topbar */
  body.course-page > header:not(.course-topbar) {
    display: none;
  }

  .portfolio-back,
  .course-nav-toggle {
    display: none !important;
  }

  body.course-page .layout {
    padding-top: var(--header-height);
    flex-direction: column;
  }

  body.course-page .layout > main {
    width: 100% !important;
    padding: 1rem 1rem 5rem !important;
    max-width: 100% !important;
  }

  body.course-page .container > .content {
    margin-left: 0 !important;
    width: 100% !important;
    padding: 1rem 1rem 5rem !important;
    min-height: calc(100vh - var(--header-height));
  }

  body.course-page .container {
    display: block;
    padding-top: var(--header-height);
  }

  /* Sidebar drawer — hidden until Contents is tapped */
  body.course-page .layout > nav,
  body.course-page .container > .sidebar {
    display: none !important;
    position: fixed !important;
    top: var(--header-height) !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100% !important;
    min-width: 0 !important;
    height: auto !important;
    max-height: none !important;
    z-index: 4900 !important;
    padding: 1rem 1rem 2rem !important;
    overflow-y: auto !important;
    -webkit-overflow-scrolling: touch;
    box-shadow: none;
    border-right: none !important;
    border-bottom: none !important;
    background: var(--bg-elevated) !important;
  }

  body.course-page .layout > nav.course-nav-open,
  body.course-page .container > .sidebar.course-nav-open {
    display: block !important;
    max-height: none !important;
    height: auto !important;
    z-index: 4900 !important;
  }

  .course-nav-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    top: var(--header-height);
    z-index: 4800;
    background: rgba(8, 10, 14, 0.65);
    backdrop-filter: blur(2px);
  }

  .course-nav-backdrop.is-visible {
    display: block;
  }

  body.course-page section h2,
  body.course-page .content h2 {
    font-size: 1.25rem;
    scroll-margin-top: calc(var(--header-height) + 0.5rem);
  }

  body.course-page pre,
  body.course-page .content pre {
    padding: 1rem !important;
    font-size: 0.8rem !important;
    max-width: 100%;
  }

  body.course-page .py-editor-fab {
    bottom: 1rem;
    right: 1rem;
    padding: 0.6rem 0.9rem;
    font-size: 0.8rem;
  }
}

@media (max-width: 480px) {
  body.course-page .layout > main,
  body.course-page .container > .content {
    padding: 0.85rem 0.85rem 5rem !important;
  }

  .course-topbar-title {
    font-size: 0.78rem;
  }
}

/* Desktop: AI sidebar always visible, content in its own column */
@media (min-width: 769px) {
  body.course-page .container > .sidebar {
    display: block !important;
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    z-index: 60;
    overflow-y: auto;
  }

  body.course-page .container > .content {
    margin-left: var(--sidebar-width) !important;
    width: calc(100% - var(--sidebar-width)) !important;
    box-sizing: border-box;
  }

  .course-topbar {
    display: none;
  }
}