/* ============================================================
   n8n Course Website — Shared Stylesheet
   ============================================================ */

/* ------------------------------------------------------------
   1. CSS Custom Properties
   ------------------------------------------------------------ */
:root {
  /* Background */
  --bg-base: #0f1a2e;
  --bg-gradient-blue: #2A3388;
  --bg-gradient-cyan: #0FC3BF;

  /* Brand */
  --color-primary: #0FC3BF;
  --color-mid: #1B6EB5;
  --color-deep: #2A3388;

  /* Cards */
  --card-bg: rgba(255, 255, 255, 0.06);
  --card-bg-fallback: rgba(20, 35, 60, 0.9);
  --card-border: rgba(255, 255, 255, 0.12);
  --card-border-hover: rgba(15, 195, 191, 0.4);
  --card-blur: 12px;
  --card-radius: 16px;
  --radius-sm: 8px;

  /* Text */
  --text-primary: #fff;
  --text-secondary: #c8d6e5;
  --text-muted: #8395a7;

  /* Stage colors */
  --stage-foundation: #0FC3BF;
  --stage-ai: #4A90D9;
  --stage-advanced: #9B59B6;
  --stage-capstone: #E67E22;

  /* Typography */
  --font-zh: 'Noto Sans TC', system-ui, -apple-system, sans-serif;
  --font-en: 'Space Grotesk', system-ui, -apple-system, sans-serif;

  /* Motion */
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-zh);
  color: var(--text-primary);
  background-color: var(--bg-base);
  background-image:
    radial-gradient(ellipse at 20% 50%, var(--bg-gradient-blue) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(15, 195, 191, 0.45) 0%, transparent 40%);
  background-attachment: fixed;
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img {
  max-width: 100%;
  display: block;
}

ul, ol {
  list-style: none;
}

/* ------------------------------------------------------------
   3. Typography
   ------------------------------------------------------------ */
h1 {
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
}

h2 {
  font-size: 1.75rem;
  font-weight: 600;
  line-height: 1.3;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
}

h4 {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.5;
}

.font-en {
  font-family: var(--font-en);
}

/* ------------------------------------------------------------
   4. Hero Section
   ------------------------------------------------------------ */
.hero {
  position: relative;
  text-align: center;
  padding: 80px 24px 60px;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--color-deep) 0%, var(--color-mid) 50%, var(--color-primary) 100%);
  opacity: 0.12;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero-title-row {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 14px;
}

.hero-logo {
  width: 44px;
  height: auto;
  flex-shrink: 0;
}

.hero h1 {
  font-size: clamp(28px, 5vw, 48px);
  font-weight: 900;
  background: linear-gradient(135deg, #fff 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.hero-subtitle {
  font-size: clamp(15px, 2.5vw, 18px);
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-meta {
  display: flex;
  justify-content: center;
  gap: 28px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: 14px;
}

.hero-meta-item svg {
  width: 18px;
  height: 18px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.grade-query-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 24px;
  background: rgba(15, 195, 191, 0.15);
  border: 1px solid rgba(15, 195, 191, 0.3);
  border-radius: 100px;
  color: var(--color-primary);
  font-family: var(--font-zh);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}

.grade-query-btn:hover {
  background: rgba(15, 195, 191, 0.25);
  border-color: rgba(15, 195, 191, 0.5);
}

/* ------------------------------------------------------------
   5. Stage Navigation
   ------------------------------------------------------------ */
.stage-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 26, 46, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--card-border);
  padding: 0 1rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.stage-nav-inner {
  display: flex;
  justify-content: center;
  gap: 0.25rem;
  max-width: 720px;
  margin: 0 auto;
}

.stage-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.25rem;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  color: var(--text-muted);
  font-family: var(--font-zh);
  font-size: 0.875rem;
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--transition), border-color var(--transition);
}

.stage-btn::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.stage-btn[data-stage="foundation"]::before { background: var(--stage-foundation); }
.stage-btn[data-stage="ai"]::before          { background: var(--stage-ai); }
.stage-btn[data-stage="advanced"]::before    { background: var(--stage-advanced); }
.stage-btn[data-stage="capstone"]::before    { background: var(--stage-capstone); }

.stage-btn:hover {
  color: var(--text-primary);
}

.stage-btn.active {
  color: var(--text-primary);
}

.stage-btn.active[data-stage="foundation"] { border-bottom-color: var(--stage-foundation); }
.stage-btn.active[data-stage="ai"]         { border-bottom-color: var(--stage-ai); }
.stage-btn.active[data-stage="advanced"]   { border-bottom-color: var(--stage-advanced); }
.stage-btn.active[data-stage="capstone"]   { border-bottom-color: var(--stage-capstone); }

/* ------------------------------------------------------------
   6. Timeline & Course Cards
   ------------------------------------------------------------ */
.timeline-section {
  max-width: 900px;
  margin: 0 auto;
  padding: 48px 24px 60px;
}

.stage-group {
  margin-bottom: 48px;
}

.stage-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.stage-dot {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}

.stage-header h2 {
  font-size: 20px;
  font-weight: 700;
}

.stage-range {
  font-size: 14px;
  color: var(--text-secondary);
  margin-left: auto;
  font-family: var(--font-en);
}

.timeline {
  position: relative;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: rgba(255, 255, 255, 0.08);
}

.course-card {
  position: relative;
  margin-bottom: 24px;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.card-inner {
  background: var(--card-bg);
  backdrop-filter: blur(var(--card-blur));
  -webkit-backdrop-filter: blur(var(--card-blur));
  border: 1px solid var(--card-border);
  border-radius: var(--card-radius);
  padding: 24px;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
  cursor: default;
}

/* Fallback for browsers without backdrop-filter */
@supports not (backdrop-filter: blur(1px)) {
  .course-card {
    background: var(--card-bg-fallback);
  }
}

.course-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.card-inner:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--card-border-hover);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

/* Timeline dot */
.course-card::before {
  content: '';
  position: absolute;
  left: -33px;
  top: 28px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 2px solid var(--stage-foundation);
  background: var(--bg-base);
  z-index: 1;
}

.course-card[data-stage="foundation"]::before { border-color: var(--stage-foundation); }
.course-card[data-stage="ai"]::before { border-color: var(--stage-ai); }
.course-card[data-stage="advanced"]::before { border-color: var(--stage-advanced); }
.course-card[data-stage="capstone"]::before { border-color: var(--stage-capstone); }

/* ------------------------------------------------------------
   7. Card Internals
   ------------------------------------------------------------ */
.card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 12px;
}

.card-date {
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
  padding-top: 2px;
}

.card-lesson {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 100px;
  white-space: nowrap;
}

.card-lesson[data-stage="foundation"] { background: rgba(15, 195, 191, 0.15); color: var(--stage-foundation); }
.card-lesson[data-stage="ai"]         { background: rgba(74, 144, 217, 0.15); color: var(--stage-ai); }
.card-lesson[data-stage="advanced"]   { background: rgba(155, 89, 182, 0.15); color: var(--stage-advanced); }
.card-lesson[data-stage="capstone"]   { background: rgba(230, 126, 34, 0.15); color: var(--stage-capstone); }

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.card-summary {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

/* 8. Card Actions */
.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.card-actions a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.45em 0.85em;
  border-radius: var(--radius-sm);
  transition: opacity var(--transition);
}

.card-actions a:hover {
  opacity: 0.8;
}

.card-actions .btn-download {
  background: rgba(27, 110, 181, 0.15);
  color: #4A90D9;
}

.card-actions .btn-homework {
  background: rgba(15, 195, 191, 0.15);
  color: var(--color-primary);
}

/* Expandable details / objectives */
.card-details {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.4s ease, opacity 0.3s ease;
}

.card-details.open,
.card-inner:hover .card-details,
.card-inner.expanded .card-details {
  max-height: 600px;
  opacity: 1;
}

.card-details ul {
  padding: 0.75rem 0 0 1.25rem;
  list-style: disc;
}

.card-details li {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

/* ------------------------------------------------------------
   9. Modal
   ------------------------------------------------------------ */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.7);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  width: 90%;
  max-width: 500px;
  background: rgba(20, 35, 60, 0.95);
  border: 1px solid var(--card-border);
  border-radius: var(--card-radius);
  padding: 2rem;
  position: relative;
  transform: translateY(20px);
  transition: transform var(--transition);
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-content h2,
.modal-content h3 {
  margin-bottom: 1rem;
}

.modal-close-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 24px;
  cursor: pointer;
  padding: 4px 8px;
  line-height: 1;
  border-radius: 4px;
  transition: color var(--transition), background var(--transition);
}

.modal-close-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.1);
}

.modal-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-primary);
  font-family: var(--font-zh);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition);
  margin-bottom: 1rem;
}

.modal-input:focus {
  border-color: var(--color-primary);
}

.modal-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.5rem;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--bg-base);
  font-family: var(--font-zh);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity var(--transition);
}

.modal-btn:hover {
  opacity: 0.85;
}

/* ------------------------------------------------------------
   10. Student Status Display (inside modal)
   ------------------------------------------------------------ */
.status-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 1rem;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.status-card .status-icon {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.status-card .status-icon.submitted {
  background: rgba(15, 195, 191, 0.2);
  color: var(--color-primary);
}

.status-card .status-icon.pending {
  background: rgba(230, 126, 34, 0.2);
  color: var(--stage-capstone);
}

.status-card .status-icon.not-submitted {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
}

.status-card .status-text {
  flex: 1;
}

.status-card .status-text .status-title {
  font-size: 0.9rem;
  font-weight: 500;
}

.status-card .status-text .status-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   11. Assignment Page (hw.html)
   ------------------------------------------------------------ */
.hw-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 48px 24px 60px;
}

.hw-back {
  display: inline-block;
  font-size: 14px;
  color: var(--color-primary);
  margin-bottom: 24px;
  transition: opacity var(--transition);
}

.hw-back:hover {
  opacity: 0.7;
}

.hw-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

.hw-deadline {
  font-size: 13px;
  color: var(--text-muted);
}

.hw-title {
  font-size: clamp(22px, 4vw, 32px);
  font-weight: 700;
  margin-bottom: 24px;
}

.hw-goal {
  border-left: 3px solid var(--color-primary);
  background: rgba(15, 195, 191, 0.08);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 32px;
}

.hw-goal-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.hw-goal p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

.hw-notice {
  background: rgba(230, 126, 34, 0.1);
  border-left: 3px solid #E67E22;
  padding: 14px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 28px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.hw-section {
  margin-bottom: 32px;
}

.hw-section h2 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.hw-requirements {
  list-style: decimal;
  padding-left: 24px;
}

.hw-requirements li {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 10px;
  line-height: 1.7;
}

.hw-requirements li code {
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 13px;
  font-family: 'Space Grotesk', monospace;
  color: var(--color-primary);
}

.hw-criteria {
  list-style: none;
  padding: 0;
}

.hw-criteria li {
  position: relative;
  padding-left: 28px;
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.6;
}

.hw-criteria li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 4px;
  width: 16px;
  height: 16px;
  border: 2px solid var(--color-primary);
  border-radius: 3px;
}

.hw-resources {
  list-style: none;
  padding: 0;
}

.hw-resources li {
  margin-bottom: 8px;
}

.hw-resources a {
  font-size: 14px;
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

.hw-resources a:hover {
  color: var(--color-primary);
}

/* Submission section - consistent font size */
.hw-submission-content {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.hw-submission-content code {
  background: rgba(255, 255, 255, 0.08);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 14px;
  font-family: var(--font-en);
  color: var(--color-primary);
}

.hw-submission-content strong,
.hw-submission-content .hw-highlight {
  color: #FBBF24;
}

/* Yellow bold highlight for emphasis across hw pages */
.hw-highlight {
  color: #FBBF24;
  font-weight: 700;
}

.hw-submission-content a {
  color: var(--color-mid);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.hw-submission-content a:hover {
  color: var(--color-primary);
}

/* Assignment images - side by side, clickable */
.hw-images-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  align-items: start;
}

.hw-images-grid .hw-figure img {
  width: 100%;
  height: 280px;
  object-fit: contain;
  background: rgba(255, 255, 255, 0.03);
}

.hw-figure {
  margin: 0;
  cursor: pointer;
}

.hw-figure img {
  max-width: 100%;
  border-radius: var(--radius-sm);
  border: 1px solid var(--card-border);
  transition: border-color var(--transition), opacity var(--transition);
}

.hw-figure:hover img {
  border-color: var(--card-border-hover);
  opacity: 0.85;
}

.hw-figure figcaption {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 6px;
  text-align: center;
}

/* Lightbox for image zoom */
.hw-lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.85);
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  padding: 24px;
}

.hw-lightbox.active {
  display: flex;
}

.hw-lightbox img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius-sm);
  box-shadow: 0 8px 48px rgba(0, 0, 0, 0.5);
}

.hw-lightbox-close {
  position: absolute;
  top: 20px;
  right: 28px;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.15);
  border: none;
  border-radius: 50%;
  color: #fff;
  font-size: 22px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.hw-lightbox-close:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* ------------------------------------------------------------
   12. Admin Page
   ------------------------------------------------------------ */
.admin-login {
  max-width: 380px;
  margin: 8rem auto;
  text-align: center;
}

.admin-login h2 {
  margin-bottom: 1.5rem;
}

.admin-table-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--card-border);
  border-radius: var(--card-radius);
  margin-bottom: 2rem;
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  min-width: 600px;
}

.admin-table th,
.admin-table td {
  padding: 0.65rem 0.85rem;
  text-align: left;
  border-bottom: 1px solid var(--card-border);
  white-space: nowrap;
}

.admin-table th {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-muted);
  font-weight: 600;
  position: sticky;
  top: 0;
  z-index: 2;
}

/* Sticky first column */
.admin-table th:first-child,
.admin-table td:first-child {
  position: sticky;
  left: 0;
  z-index: 3;
  background: var(--bg-base);
}

.admin-table th:first-child {
  z-index: 4;
}

.admin-table td {
  color: var(--text-secondary);
}

/* Cell status colors */
.admin-table .cell-submitted {
  color: var(--color-primary);
}

.admin-table .cell-pending {
  color: var(--stage-capstone);
}

.admin-table .cell-missing {
  color: var(--text-muted);
  opacity: 0.6;
}

/* Stat bar chart */
.stat-bar {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 60px;
}

.stat-bar .bar {
  flex: 1;
  min-width: 18px;
  background: var(--color-primary);
  border-radius: 3px 3px 0 0;
  position: relative;
  transition: height var(--transition);
}

.stat-bar .bar span {
  position: absolute;
  top: -1.2em;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  font-family: var(--font-en);
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   13. Responsive (max-width: 640px)
   ------------------------------------------------------------ */
@media (max-width: 640px) {
  .hero {
    padding: 3.5rem 1rem 2rem;
  }

  .hero-title {
    font-size: 1.75rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-meta {
    gap: 0.75rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  h2 {
    font-size: 1.35rem;
  }

  .stage-nav-inner {
    justify-content: flex-start;
  }

  .stage-btn {
    padding: 0.75rem 0.85rem;
    font-size: 0.8rem;
  }

  .timeline {
    padding: 0 1rem 3rem;
  }

  .timeline::before {
    left: 1rem;
  }

  .course-card {
    margin-left: 1.5rem;
    padding: 1.15rem;
  }

  .course-card::before {
    left: -1.85rem;
  }

  .card-title {
    font-size: 1rem;
  }

  .modal-content {
    padding: 1.5rem;
  }

  .hw-container {
    padding: 2rem 1rem 3rem;
  }

  .admin-login {
    margin: 4rem auto;
    padding: 0 1rem;
  }
}

/* ------------------------------------------------------------
   14. Reduced Motion
   ------------------------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  html {
    scroll-behavior: auto;
  }

  .course-card {
    opacity: 1;
    transform: none;
  }
}

/* ------------------------------------------------------------
   15. Unpublished Lesson Cards
   ------------------------------------------------------------ */
.unpublished {
  opacity: 0.5;
}

.unpublished .card-actions {
  pointer-events: none;
}

/* ------------------------------------------------------------
   16. Footer
   ------------------------------------------------------------ */
.site-footer {
  text-align: center;
  padding: 40px 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
  font-size: 14px;
}

.site-footer .footer-logo {
  width: 40px;
  height: auto;
  margin: 0 auto 10px;
}