/* ============================================================
   SWAYAM Course Explorer — Stylesheet
   Design tokens follow the brief's palette exactly:
   Primary #0A2342, Accent #F4B400, Background #F5F7FA,
   Cards white, Text dark grey, Buttons dark blue, Hover gold.
   ============================================================ */

:root {
  --color-primary: #0A2342;
  --color-primary-light: #123a68;
  --color-accent: #F4B400;
  --color-bg: #F5F7FA;
  --color-card: #FFFFFF;
  --color-text: #2B2E33;
  --color-text-muted: #6B7280;
  --color-border: #E3E7EE;
  --color-btn: #0A2342;
  --color-btn-hover: #F4B400;
  --color-success: #1E8E5A;
  --color-danger: #C0392B;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 3px rgba(10, 35, 66, 0.08);
  --shadow-md: 0 6px 20px rgba(10, 35, 66, 0.10);
  --shadow-lg: 0 16px 40px rgba(10, 35, 66, 0.16);

  --header-height: auto;
  --transition-fast: 0.15s ease;
  --transition-base: 0.25s ease;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --color-primary: #12335c;
  --color-primary-light: #1c4a83;
  --color-accent: #F4B400;
  --color-bg: #0F1620;
  --color-card: #182233;
  --color-text: #E7EAF0;
  --color-text-muted: #9AA5B4;
  --color-border: #2A3547;
  --color-btn: #1c4a83;
  --color-btn-hover: #F4B400;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 6px 20px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.55);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition-base), color var(--transition-base);
}
img { max-width: 100%; display: block; }
a { color: inherit; }
button { font-family: inherit; cursor: pointer; }
input, select { font-family: inherit; }

/* Defensive rule: whenever JS sets `el.hidden = true`, this must win over
   any class that sets its own `display` value (e.g. display:flex/grid),
   since attribute and class selectors can otherwise tie in specificity
   and the class rule can end up winning by source order. */
[hidden] { display: none !important; }

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--color-accent); color: var(--color-primary);
  padding: 10px 16px; z-index: 2000; border-radius: 0 0 8px 0;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.header-top-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 20px 14px;
  gap: 16px;
}

.brand { display: flex; align-items: center; gap: 14px; }
.brand-logo { border-radius: 8px; background: rgba(255,255,255,0.12); padding: 6px; }
.brand-title { font-size: clamp(1.3rem, 2.4vw, 1.8rem); margin: 0; font-weight: 800; letter-spacing: -0.02em; }
.brand-subtitle { margin: 4px 0 0; font-size: 0.92rem; color: rgba(255,255,255,0.78); max-width: 46ch; }

.header-actions { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }

.site-credit-link {
  color: rgba(255,255,255,0.85);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 20px;
  background: rgba(255,255,255,0.10);
  transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
}
.site-credit-link:hover { background: var(--color-accent); color: var(--color-primary); transform: translateY(-1px); }

.icon-btn {
  position: relative;
  background: rgba(255,255,255,0.10);
  border: none;
  color: #fff;
  width: 42px; height: 42px;
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}
.icon-btn:hover { background: var(--color-accent); color: var(--color-primary); transform: translateY(-1px); }
.icon-btn .icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

.badge {
  position: absolute; top: -2px; right: -2px;
  background: var(--color-accent); color: var(--color-primary);
  font-size: 0.65rem; font-weight: 800;
  min-width: 18px; height: 18px; border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  padding: 0 4px;
}

.header-stats { background: rgba(0,0,0,0.14); }
.stats-row { display: flex; gap: 14px; padding: 12px 20px; flex-wrap: wrap; }
.stat-pill {
  background: rgba(255,255,255,0.08);
  border-radius: 999px;
  padding: 6px 16px;
  display: flex; align-items: baseline; gap: 6px;
  font-size: 0.85rem;
}
.stat-number { font-weight: 800; font-size: 1rem; color: var(--color-accent); }
.stat-label { color: rgba(255,255,255,0.82); }

.search-section { padding: 18px 20px 26px; }
.search-box {
  position: relative;
  max-width: 780px;
  margin: 0 auto;
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
}
.search-icon {
  width: 20px; height: 20px;
  margin-left: 20px;
  fill: none; stroke: var(--color-text-muted); stroke-width: 2;
  flex-shrink: 0;
}
.search-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  padding: 18px 12px;
  font-size: 1.02rem;
  color: var(--color-text);
  border-radius: var(--radius-lg);
}
.search-clear {
  background: none; border: none; color: var(--color-text-muted);
  font-size: 1.4rem; padding: 0 20px; line-height: 1;
}
.search-clear:hover { color: var(--color-danger); }

/* ============================================================
   LAYOUT
   ============================================================ */
.app-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 28px;
  padding-top: 28px;
  padding-bottom: 60px;
  align-items: start;
}

.filter-drawer-toggle {
  display: none;
  align-items: center; gap: 8px;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  font-weight: 600;
  color: var(--color-primary);
  box-shadow: var(--shadow-sm);
  margin-bottom: 12px;
  grid-column: 1 / -1;
}
.filter-drawer-toggle .icon { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; }

.filter-drawer-backdrop {
  position: fixed; inset: 0; background: rgba(10,35,66,0.5);
  z-index: 900;
}

/* ============================================================
   FILTERS SIDEBAR
   ============================================================ */
.filters-sidebar {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 20px;
  position: sticky;
  top: 20px;
  max-height: calc(100vh - 40px);
  overflow-y: auto;
}

.filters-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 8px;
  gap: 8px;
}
.filters-header h2 { margin: 0; font-size: 1.05rem; color: var(--color-primary); }
.filter-drawer-close { display: none; }

.link-btn {
  background: none; border: none; color: var(--color-primary-light);
  font-weight: 600; font-size: 0.85rem; text-decoration: underline;
  padding: 4px;
}
.link-btn:hover { color: var(--color-accent); }
[data-theme="dark"] .link-btn { color: #7fb3e8; }

.filter-group { padding: 14px 0; border-bottom: 1px solid var(--color-border); }
.filter-group:last-child { border-bottom: none; }
.filter-group h3 { margin: 0 0 10px; font-size: 0.88rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--color-text-muted); }

.favourite-providers-block .chip-list { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: 999px; padding: 4px 12px; font-size: 0.8rem;
  display: inline-flex; align-items: center; gap: 6px;
}

.filter-search-input, .select-input {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 0.88rem;
  margin-bottom: 8px;
}
.filter-search-input:focus, .select-input:focus { border-color: var(--color-accent); }

.checkbox-list { display: flex; flex-direction: column; gap: 6px; }
.checkbox-list-scroll { max-height: 190px; overflow-y: auto; padding-right: 4px; }

.checkbox-row {
  display: flex; align-items: center; gap: 8px;
  font-size: 0.88rem;
  padding: 3px 4px;
  border-radius: 6px;
  cursor: pointer;
}
.checkbox-row:hover { background: var(--color-bg); }
.checkbox-row input { accent-color: var(--color-primary); width: 15px; height: 15px; flex-shrink: 0; }
.checkbox-row .count { margin-left: auto; color: var(--color-text-muted); font-size: 0.78rem; }
.checkbox-row .pin-star { margin-left: 6px; background: none; border: none; color: var(--color-text-muted); font-size: 0.9rem; }
.checkbox-row .pin-star.pinned { color: var(--color-accent); }

/* ============================================================
   RESULTS AREA
   ============================================================ */
.results-toolbar {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  margin-bottom: 12px;
}
.results-count { font-weight: 600; color: var(--color-text-muted); font-size: 0.92rem; }
.toolbar-controls { display: flex; align-items: center; gap: 10px; }

.active-filter-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.active-filter-chips .chip { background: var(--color-primary); color: #fff; border: none; }
.active-filter-chips .chip button { background: none; border: none; color: #fff; font-weight: 800; cursor: pointer; }

.btn {
  border: none; border-radius: var(--radius-sm);
  padding: 10px 18px; font-weight: 700; font-size: 0.88rem;
  transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}
.btn-primary { background: var(--color-btn); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--color-btn-hover); color: var(--color-primary); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-secondary { background: var(--color-card); color: var(--color-primary); border: 1px solid var(--color-border); }
.btn-secondary:hover { background: var(--color-accent); border-color: var(--color-accent); color: var(--color-primary); }

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

/* ---------- Course Card ---------- */
.course-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 20px;
  display: flex; flex-direction: column; gap: 10px;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  border: 1px solid transparent;
}
.course-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--color-accent); }

.card-top-row { display: flex; align-items: flex-start; justify-content: space-between; gap: 10px; }
.provider-badge {
  background: var(--color-primary); color: #fff;
  font-size: 0.72rem; font-weight: 800; text-transform: uppercase;
  padding: 4px 10px; border-radius: 999px; letter-spacing: 0.03em;
  white-space: nowrap;
}
.card-compare-checkbox { display: flex; align-items: center; gap: 4px; font-size: 0.72rem; color: var(--color-text-muted); }

.course-title {
  font-size: 1.05rem; font-weight: 700; margin: 0;
  color: var(--color-primary); line-height: 1.35;
  cursor: pointer;
}
[data-theme="dark"] .course-title { color: #cfe0f5; }
.course-title:hover { color: var(--color-accent); }

.course-institution { font-size: 0.88rem; color: var(--color-text-muted); font-weight: 600; }

.course-meta-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 6px 12px;
  font-size: 0.8rem; color: var(--color-text-muted);
  margin-top: 4px;
}
.course-meta-grid .meta-label { font-weight: 700; color: var(--color-text); }

.cert-pill {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 0.76rem; font-weight: 700; padding: 2px 9px; border-radius: 999px;
  width: fit-content;
}
.cert-pill.yes { background: rgba(30,142,90,0.12); color: var(--color-success); }
.cert-pill.no { background: rgba(192,57,43,0.10); color: var(--color-danger); }
.cert-pill.unknown { background: var(--color-bg); color: var(--color-text-muted); }

.card-actions { display: flex; gap: 8px; margin-top: auto; padding-top: 8px; flex-wrap: wrap; }
.card-actions .btn { padding: 8px 12px; font-size: 0.8rem; flex: 1; text-align: center; }
.icon-action-btn {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); width: 38px; height: 38px;
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--color-text-muted); flex-shrink: 0;
}
.icon-action-btn svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; }
.icon-action-btn:hover { border-color: var(--color-accent); color: var(--color-primary); }
.icon-action-btn.bookmarked { color: var(--color-accent); }
.icon-action-btn.bookmarked svg { fill: var(--color-accent); }

/* ---------- Skeleton cards ---------- */
.skeleton-card {
  background: var(--color-card); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm); padding: 20px; height: 230px;
  display: flex; flex-direction: column; gap: 12px;
}
.skeleton-line {
  background: linear-gradient(90deg, var(--color-border) 25%, #eef1f6 37%, var(--color-border) 63%);
  background-size: 400% 100%;
  animation: skeleton-shimmer 1.4s ease infinite;
  border-radius: 6px;
}
[data-theme="dark"] .skeleton-line {
  background: linear-gradient(90deg, #223049 25%, #2e3d5b 37%, #223049 63%);
  background-size: 400% 100%;
}
@keyframes skeleton-shimmer { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }

/* ---------- Empty state ---------- */
.empty-state {
  text-align: center; padding: 70px 20px;
  color: var(--color-text-muted);
}
.empty-icon { width: 60px; height: 60px; margin: 0 auto 18px; fill: none; stroke: var(--color-border); stroke-width: 1.5; }
.empty-state h2 { color: var(--color-primary); margin: 0 0 8px; }
[data-theme="dark"] .empty-state h2 { color: #cfe0f5; }

.load-sentinel { height: 1px; }
.load-more-status { text-align: center; padding: 20px; color: var(--color-text-muted); font-size: 0.85rem; }

/* ---------- Compare tray ---------- */
.compare-tray {
  position: sticky; bottom: 16px; z-index: 50;
  margin: 16px 0;
}
.compare-tray-inner {
  background: var(--color-primary); color: #fff;
  border-radius: var(--radius-md); box-shadow: var(--shadow-lg);
  padding: 12px 18px; display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
}
.compare-tray-items { display: flex; gap: 6px; flex: 1; flex-wrap: wrap; }
.compare-tray-items .chip { background: rgba(255,255,255,0.15); color: #fff; border: none; }

/* ============================================================
   MODAL
   ============================================================ */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(10,35,66,0.55);
  display: flex; align-items: center; justify-content: center;
  padding: 20px; z-index: 1000;
}
.modal {
  background: var(--color-card); border-radius: var(--radius-lg);
  max-width: 640px; width: 100%; max-height: 88vh; overflow-y: auto;
  position: relative; box-shadow: var(--shadow-lg);
  padding: 32px;
  animation: modal-pop 0.2s ease;
}
.modal-wide { max-width: 900px; }
@keyframes modal-pop { from { transform: scale(0.96); opacity: 0; } to { transform: scale(1); opacity: 1; } }

.modal-close {
  position: absolute; top: 16px; right: 16px;
  background: var(--color-bg); border: none; width: 36px; height: 36px;
  border-radius: 50%; font-size: 1.3rem; color: var(--color-text-muted);
  line-height: 1;
}
.modal-close:hover { background: var(--color-accent); color: var(--color-primary); }

.modal-provider-badge { margin-bottom: 10px; }
.modal-title { font-size: 1.5rem; margin: 0 0 6px; color: var(--color-primary); padding-right: 30px; }
[data-theme="dark"] .modal-title { color: #cfe0f5; }
.modal-institution { color: var(--color-text-muted); font-weight: 600; margin-bottom: 18px; }

.modal-field-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px 20px;
  margin-bottom: 20px;
}
.modal-field .field-label { font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--color-text-muted); margin-bottom: 3px; }
.modal-field .field-value { font-weight: 600; }

.modal-description { margin-bottom: 20px; line-height: 1.6; }
.modal-actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* ---------- Compare table ---------- */
.table-scroll { overflow-x: auto; }
.compare-table { width: 100%; border-collapse: collapse; margin-top: 16px; }
.compare-table th, .compare-table td {
  border: 1px solid var(--color-border); padding: 10px 14px; text-align: left; font-size: 0.88rem;
}
.compare-table th { background: var(--color-bg); color: var(--color-primary); white-space: nowrap; }
[data-theme="dark"] .compare-table th { color: #cfe0f5; }

/* ============================================================
   DEDICATED PAGES (bookmarks / recent)
   ============================================================ */
.dedicated-page { padding: 32px 20px 60px; }
.dedicated-page-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; }
.dedicated-page-header h2 { color: var(--color-primary); margin: 0; }
[data-theme="dark"] .dedicated-page-header h2 { color: #cfe0f5; }

/* ============================================================
   TOAST
   ============================================================ */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  background: var(--color-primary); color: #fff;
  padding: 12px 22px; border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg); z-index: 2000; font-size: 0.9rem; font-weight: 600;
  animation: toast-in 0.2s ease;
}
@keyframes toast-in { from { opacity: 0; transform: translate(-50%, 10px); } to { opacity: 1; transform: translate(-50%, 0); } }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--color-primary); color: rgba(255,255,255,0.85);
  padding: 30px 20px; margin-top: 40px;
}
.footer-inner { display: flex; flex-direction: column; gap: 14px; align-items: center; text-align: center; }
.footer-disclaimer { max-width: 720px; font-size: 0.82rem; margin: 0; color: rgba(255,255,255,0.65); }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; justify-content: center; }
.footer-links a { font-size: 0.85rem; font-weight: 600; text-decoration: none; }
.footer-links a:hover { color: var(--color-accent); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 980px) {
  .app-layout { grid-template-columns: 1fr; }
  .filter-drawer-toggle { display: inline-flex; }

  .filters-sidebar {
    position: fixed; top: 0; left: 0; height: 100%; max-height: none;
    width: 300px; z-index: 950; border-radius: 0;
    transform: translateX(-100%);
    transition: transform var(--transition-base);
  }
  .filters-sidebar.open { transform: translateX(0); }
  .filter-drawer-close { display: inline-flex; }
}

@media (max-width: 640px) {
  .header-top-inner { flex-direction: column; align-items: flex-start; }
  .modal { padding: 22px; }
  .modal-field-grid { grid-template-columns: 1fr; }
  .course-grid { grid-template-columns: 1fr; }
}

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