/* Shared Premium Course theme — light + dark
   Works with existing --bg/--bg2/--bg3/--bdr/--blue/--teal/--text/--sl tokens */

:root {
  --purple: #a78bfa;
  --green: #4ade80;
  --amber: #fbbf24;
  --red: #f87171;
  --pink: #f472b6;
  --nav-bg: rgba(2, 6, 23, 0.92);
  --nav-text: #f8fafc;
  --heading: #f8fafc;
  --overlay: rgba(2, 6, 23, 0.88);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --card-hover: rgba(56, 189, 248, 0.35);
  --code-bg: #0b1220;
  --code-text: #c8d3e8;
  --surface-glow: rgba(56, 189, 248, 0.08);
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #f1f5f9;
  --bg2: #ffffff;
  --bg3: #f8fafc;
  --bdr: rgba(15, 23, 42, 0.1);
  --blue: #0284c7;
  --teal: #0d9488;
  --purple: #7c3aed;
  --text: #0f172a;
  --sl: #64748b;
  --green: #16a34a;
  --amber: #b45309;
  --red: #dc2626;
  --pink: #db2777;
  --nav-bg: rgba(255, 255, 255, 0.94);
  --nav-text: #0f172a;
  --heading: #0f172a;
  --overlay: rgba(15, 23, 42, 0.45);
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.08);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.1);
  --card-hover: rgba(2, 132, 199, 0.4);
  --code-bg: #1e293b;
  --code-text: #e2e8f0;
  --surface-glow: rgba(2, 132, 199, 0.06);
  color-scheme: light;
}

/* Smooth theme switch */
html { scroll-behavior: smooth; }
body {
  background: var(--bg) !important;
  color: var(--text) !important;
  transition: background 0.25s ease, color 0.25s ease;
}

/* Professional sticky nav */
.navbar,
nav.navbar {
  background: var(--nav-bg) !important;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--bdr) !important;
  gap: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}
.navbar-logo,
.navbar .navbar-logo {
  color: var(--nav-text) !important;
}
.back-link,
.back-btn,
.navbar a,
nav.navbar a {
  color: var(--sl) !important;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s, background 0.2s, border-color 0.2s;
}
.back-link,
.back-btn {
  padding: 0.35rem 0.7rem;
  border-radius: 8px;
  border: 1px solid transparent;
}
.back-link:hover,
.back-btn:hover,
.navbar a:hover,
nav.navbar a:hover {
  color: var(--blue) !important;
  text-decoration: none !important;
}
.back-link:hover,
.back-btn:hover {
  background: var(--bg3);
  border-color: var(--bdr);
}

/* Light-mode headings that were hardcoded #fff */
:root[data-theme="light"] h1,
:root[data-theme="light"] h2,
:root[data-theme="light"] h3 {
  color: var(--heading) !important;
}

/* Theme slot in nav */
.navbar-right,
.nav-end {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-left: auto;
}
#themeToggleSlot {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

/* Headings that were hardcoded light-only */
h1, h2, h3,
.section-head h2,
.lab-header h2,
.profile-name,
.module-title,
.tool-promo-body h3,
.community-hero h1 {
  color: var(--heading);
}
:root[data-theme="light"] .community-hero h1 {
  background: none;
  -webkit-text-fill-color: var(--heading);
  color: var(--heading);
}

/* Cards / panels polish */
.module,
.course-card,
.account-card,
.post-card,
.composer,
.lab-section,
.key-takeaway,
.infobox,
.warnbox,
.analogy,
.def-box,
.visual,
.code-panel,
.worked-example {
  box-shadow: var(--shadow-sm);
}

.module,
.course-hero,
.lab-section,
.account-card,
.post-card,
.composer {
  border-radius: 14px;
}

/* Soften neon accents in light mode */
:root[data-theme="light"] .badge,
:root[data-theme="light"] .subtopic-status.ready,
:root[data-theme="light"] .access-status.enrolled,
:root[data-theme="light"] .status-approved {
  color: var(--green) !important;
}
:root[data-theme="light"] .coming-soon-badge,
:root[data-theme="light"] .subtopic-status.soon,
:root[data-theme="light"] .access-status.expired,
:root[data-theme="light"] .status-pending {
  color: var(--amber) !important;
}

/* Footer */
footer {
  background: var(--bg2) !important;
  color: var(--sl) !important;
  border-top: 1px solid var(--bdr) !important;
}

/* Auth loading matches theme */
#authLoading {
  background: var(--bg) !important;
}

/* Inputs */
input, select, textarea {
  background: var(--bg3) !important;
  color: var(--text) !important;
  border-color: var(--bdr) !important;
}
input:focus, select:focus, textarea:focus {
  border-color: var(--blue) !important;
}

/* Lesson content readability */
.container {
  max-width: min(840px, 100%);
}
.crumb { color: var(--sl); }
.crumb a { color: var(--sl); }
.crumb a:hover { color: var(--blue); }

.lesson-tag {
  color: var(--blue) !important;
}

/* Code panels stay dark for contrast (intentional) */
.code-panel,
pre[id^="code-"],
.cp-card {
  background: var(--code-bg);
}

/* Lesson diagrams (SVG) and ASCII waveforms: the per-page inline CSS sets
   background:var(--bg3), which follows the theme — but the SVG text/fill
   colors inside (#e2e8f0, #fff, etc.) were authored for a dark surface
   only. In light mode that becomes light-on-light and disappears. Force
   these to the same always-dark surface as code panels, same reasoning. */
.diagram-wrap,
.wave-ascii {
  background: var(--code-bg) !important;
  border-color: rgba(148, 163, 184, 0.15) !important;
}
.diagram-caption {
  color: #94a3b8 !important;
}

/* WaveDrom timing diagrams (STA course) are the INVERSE case of the SVGs
   above: WaveDrom's upstream "default" skin draws stroke:#000 and
   fill:#0041c4 — authored for a light surface. On our dark page these
   rendered black-on-black, i.e. invisible in the default theme. These
   containers also had no CSS defined anywhere, so they had no panel,
   padding, or horizontal scroll. Give them a permanently light panel in
   both themes, which is how WaveDrom is meant to be presented. */
.wavedrom-container,
.diagram-container {
  background: #ffffff;
  border: 1px solid var(--bdr);
  border-radius: 12px;
  padding: 1rem;
  margin: 1.4rem 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  max-width: 100%;
}
.wavedrom-container svg,
.diagram-container svg {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto;
}
.code-panel .code-panel-head {
  border-bottom: 1px solid var(--bdr);
}

/* Canvas / lab wraps */
.lab-canvas-wrap,
.lab-sliders {
  background: var(--bg3) !important;
  border-color: var(--bdr) !important;
}

/* Module accordion polish */
.module {
  background: var(--bg2) !important;
  border: 1px solid var(--bdr) !important;
  overflow: hidden;
}
.module-header:hover {
  background: var(--surface-glow) !important;
}
.module-title { color: var(--heading) !important; }
.subtopic {
  border-top: 1px solid var(--bdr) !important;
  color: var(--text) !important;
}
.subtopic-link { color: var(--text) !important; }
.subtopic-link.ready-link:hover { color: var(--blue) !important; }

/* Progress */
.course-hero {
  background: linear-gradient(120deg, var(--surface-glow), rgba(167, 139, 250, 0.08)) !important;
  border: 1px solid var(--bdr) !important;
}
.course-progress-track {
  background: var(--bg3) !important;
}

/* No-access */
.no-access h1 { color: var(--red) !important; }

/* Soften hardcoded hex whites that break light mode */
:root[data-theme="light"] .navbar-logo,
:root[data-theme="light"] .post-author,
:root[data-theme="light"] .comment-author,
:root[data-theme="light"] .profile-name,
:root[data-theme="light"] .mc-name,
:root[data-theme="light"] .history-course,
:root[data-theme="light"] .section-head h2,
:root[data-theme="light"] .lab-header h2,
:root[data-theme="light"] .key-takeaway h3,
:root[data-theme="light"] .def-box p,
:root[data-theme="light"] .formula-box .formula,
:root[data-theme="light"] .rule-card .rule-title,
:root[data-theme="light"] .we-table tr:last-child td {
  color: var(--heading) !important;
}

:root[data-theme="light"] .chat-bubble.from-user,
:root[data-theme="light"] .post-btn,
:root[data-theme="light"] .tool-promo-cta,
:root[data-theme="light"] .course-badge {
  color: #fff !important;
}
:root[data-theme="light"] .tool-promo-cta,
:root[data-theme="light"] .course-badge,
:root[data-theme="light"] .post-btn {
  color: #020617 !important;
}

/* Visual / SVG lesson boxes */
.visual {
  background: var(--bg3) !important;
  border-color: var(--bdr) !important;
}

/* Status chips use theme tokens */
.access-status.locked {
  background: var(--bg3) !important;
  color: var(--sl) !important;
  border-color: var(--bdr) !important;
}

/* Course index / lesson polish */
.course-hero strong {
  color: var(--heading) !important;
}
:root[data-theme="light"] .community-hero h1 {
  background: none !important;
  -webkit-text-fill-color: var(--heading) !important;
}
.lesson-nav a {
  color: var(--sl) !important;
  font-weight: 600;
  padding: 0.55rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--bdr);
  background: var(--bg2);
  transition: all 0.2s;
  text-decoration: none !important;
}
.lesson-nav a:hover {
  color: var(--blue) !important;
  border-color: var(--card-hover);
  box-shadow: var(--shadow-sm);
}
.key-takeaway {
  background: linear-gradient(120deg, var(--surface-glow), rgba(45, 212, 191, 0.06)) !important;
  border-color: var(--bdr) !important;
}
.key-takeaway h3 {
  color: var(--blue) !important;
}
nav:not(.navbar) {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
  padding: 0.85rem 1.25rem;
  background: var(--nav-bg);
  border-bottom: 1px solid var(--bdr);
  backdrop-filter: blur(12px);
}

/* ============================================================
   Premium-wide responsive layout (phone / tablet / desktop)
   ============================================================ */
html, body {
  overflow-x: clip;
  max-width: 100%;
}
img, svg, video, canvas {
  max-width: 100%;
  height: auto;
}
.container,
.sneak-wrap {
  width: 100%;
  box-sizing: border-box;
  padding-left: max(1rem, env(safe-area-inset-left));
  padding-right: max(1rem, env(safe-area-inset-right));
}
.navbar,
nav.navbar {
  padding-left: max(0.85rem, env(safe-area-inset-left));
  padding-right: max(0.85rem, env(safe-area-inset-right));
}
.navbar-right,
.nav-end {
  flex-wrap: wrap;
  max-width: 100%;
}
.subtopic {
  flex-wrap: wrap;
  align-items: flex-start;
}
.subtopic-link {
  min-width: 0;
  overflow-wrap: anywhere;
  word-break: break-word;
}
.subtopic-status {
  margin-left: 0;
}
.module-title-wrap {
  min-width: 0;
}
.module-title {
  overflow-wrap: anywhere;
}
.module-subtopics.open {
  max-height: none !important;
}
.map-table,
.we-table,
table {
  max-width: 100%;
}
.section,
.lab-section,
.diagram-wrap,
.visual,
.wave-ascii,
.challenge-diagram,
.challenge-table-wrap,
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  max-width: 100%;
}
.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}
.lesson-nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  box-sizing: border-box;
}
.reason-grid,
.card-grid {
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 210px), 1fr));
}
.flow-rail {
  justify-content: flex-start;
}
.flow-chip {
  white-space: normal;
}
.post-actions,
.challenge-footer,
.composer-footer,
.history-item {
  flex-wrap: wrap;
}
.post-text,
.challenge-text {
  overflow-wrap: anywhere;
  word-break: break-word;
}

@media (max-width: 1024px) {
  .container {
    max-width: 100%;
  }
  h1 {
    font-size: clamp(1.35rem, 3.2vw, 1.85rem);
  }
}

@media (max-width: 768px) {
  .navbar,
  nav.navbar {
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;
    gap: 0.55rem;
  }
  .navbar-logo {
    font-size: 1rem !important;
  }
  .back-link,
  .back-btn {
    font-size: 0.82rem;
    padding: 0.4rem 0.65rem;
    min-height: 40px;
    display: inline-flex;
    align-items: center;
  }
  .container,
  .sneak-wrap {
    padding-top: 1.25rem;
    padding-bottom: 2rem;
  }
  .module-header {
    padding: 0.95rem 1rem !important;
    gap: 0.7rem;
  }
  .module-num {
    width: 30px;
    height: 30px;
    font-size: 0.85rem;
  }
  .subtopic {
    padding: 0.75rem 1rem 0.75rem 1.1rem !important;
    gap: 0.5rem;
  }
  .lesson-nav {
    flex-direction: column;
  }
  .lesson-nav a {
    width: 100%;
    justify-content: center;
    text-align: center;
  }
  .course-hero,
  .sneak-hero,
  .account-card,
  .composer,
  .post-card,
  .challenge-card,
  .key-takeaway,
  .lab-section {
    padding-left: 1.05rem !important;
    padding-right: 1.05rem !important;
  }
  .community-hero {
    padding: 1.75rem 1rem 1.5rem !important;
  }
  .hero-stats {
    gap: 1.25rem !important;
  }
  .post-btn,
  .sim-cta,
  .sneak-cta,
  .post-challenge-btn {
    min-height: 44px;
  }
  .admin-actions {
    margin-left: 0;
    width: 100%;
  }
  .lab-canvas-wrap,
  .lab-sliders {
    overflow-x: auto;
  }
  footer {
    padding: 1.5rem 1rem !important;
  }
}

@media (max-width: 480px) {
  .container,
  .sneak-wrap {
    padding-left: max(0.75rem, env(safe-area-inset-left));
    padding-right: max(0.75rem, env(safe-area-inset-right));
  }
  h1 {
    font-size: 1.2rem !important;
    line-height: 1.3;
  }
  h2,
  .section-head h2 {
    font-size: 1.05rem !important;
  }
  .navbar-logo {
    font-size: 0.92rem !important;
  }
  .module-title {
    font-size: 0.9rem !important;
  }
  .post-card,
  .challenge-card,
  .composer {
    padding: 1rem !important;
  }
  .reaction-btn,
  .reply-btn,
  .challenge-toggle {
    min-height: 40px;
  }
}