/* ============================================================
   中華基督教會基慈小學 — 數學科教件庫 樣式表
   ============================================================ */

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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --accent: #f59e0b;
  --bg: #f8fafc;
  --surface: #ffffff;
  --text: #1e293b;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "PingFang TC", "Microsoft JhengHei", "Noto Sans TC", system-ui,
    -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-img {
  width: 44px;
  height: auto;
}

.logo h1 {
  font-size: 1.2rem;
  line-height: 1.3;
}

.school-name {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.nav-links {
  display: flex;
  gap: 8px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  background: var(--primary-light);
  color: var(--primary);
}

/* ---------- Hero Banner ---------- */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
  color: #fff;
  padding: 48px 0 40px;
  text-align: center;
}

.hero-inner {
  max-width: 700px;
  margin: 0 auto;
  padding: 0 20px;
}

.hero h2 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.hero p {
  font-size: 1.05rem;
  opacity: 0.9;
  margin-bottom: 20px;
}

.stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 1.8rem;
  font-weight: 700;
}

.stat-label {
  font-size: 0.8rem;
  opacity: 0.8;
}

/* ---------- Filter Section ---------- */
.filter-section {
  padding: 24px 0 8px;
}

.filter-bar {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px 24px;
  box-shadow: var(--shadow);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: flex-end;
}

.filter-group {
  flex: 1;
  min-width: 200px;
}

.filter-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.filter-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.chip {
  display: inline-block;
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  transition: var(--transition);
  user-select: none;
}

.chip:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.chip.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.search-group {
  min-width: 220px;
}

.search-group input {
  width: 100%;
  padding: 7px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  outline: none;
  transition: var(--transition);
}

.search-group input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

/* ---------- Resources Grid ---------- */
.resources-section {
  padding: 16px 0 48px;
}

.results-info {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 16px;
}

/* ---------- Resource Card ---------- */
.resource-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.resource-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 8px;
}

.card-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

.card-badges {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
}

.badge {
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 600;
  white-space: nowrap;
}

.badge-grade {
  background: var(--primary-light);
  color: var(--primary);
}

.badge-topic {
  background: #fef3c7;
  color: #92400e;
}

.card-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  flex: 1;
}

.card-tags {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.tag {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 10px;
  background: #f1f5f9;
  color: var(--text-secondary);
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.card-footer a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}

.card-footer a:hover {
  color: var(--primary-dark);
}

/* ---------- Empty State ---------- */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
}

.empty-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 12px;
}

.empty-state p {
  font-size: 1.1rem;
  margin-bottom: 16px;
}

/* ---------- Add Section ---------- */
.add-section {
  padding: 48px 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
}

.add-section h2 {
  font-size: 1.5rem;
  margin-bottom: 4px;
}

.section-desc {
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.add-form {
  max-width: 700px;
}

.form-row {
  display: flex;
  gap: 16px;
  margin-bottom: 0;
}

.form-field {
  flex: 1;
  margin-bottom: 16px;
}

.form-field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-family: inherit;
  outline: none;
  transition: var(--transition);
  background: var(--bg);
}

.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.form-success {
  margin-top: 16px;
  padding: 12px 16px;
  background: #dcfce7;
  color: #166534;
  border-radius: var(--radius-sm);
  font-weight: 500;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--border);
}

.btn-danger {
  background: #dc2626;
  color: #fff;
}

.btn-danger:hover {
  background: #b91c1c;
}

/* ---------- Admin Modal ---------- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.modal-box {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  max-width: 400px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
  text-align: center;
}

.modal-box h3 {
  font-size: 1.3rem;
  margin-bottom: 8px;
}

.modal-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.modal-box input[type="password"] {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  outline: none;
  text-align: center;
  transition: var(--transition);
}

.modal-box input[type="password"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.admin-error {
  color: #dc2626;
  font-size: 0.85rem;
  margin-top: 8px;
  font-weight: 500;
}

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-top: 20px;
}

/* ---------- Admin Mode ---------- */
.nav-links a.admin-active {
  background: #fef2f2;
  color: #dc2626;
  border: 1px solid #fecaca;
}

.admin-badge {
  display: inline-block;
  background: #dc2626;
  color: #fff;
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 600;
  margin-left: 6px;
}

.card-delete-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: #fef2f2;
  color: #dc2626;
  border: 1px solid #fecaca;
  border-radius: var(--radius-sm);
  padding: 4px 12px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  margin-top: 10px;
}

.card-delete-btn:hover {
  background: #dc2626;
  color: #fff;
}

/* ---------- Footer ---------- */
.footer {
  padding: 24px 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
}

.footer-note {
  font-size: 0.75rem;
  margin-top: 4px;
  opacity: 0.7;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    text-align: center;
  }

  .hero h2 {
    font-size: 1.5rem;
  }

  .filter-bar {
    flex-direction: column;
  }

  .filter-group {
    min-width: 100%;
  }

  .resource-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    flex-direction: column;
    gap: 0;
  }

  .stats {
    gap: 20px;
  }
}

/* ---------- Animation ---------- */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.resource-card {
  animation: fadeIn 0.3s ease both;
}