/* ═══════════════════════════════════════════
   Virtual Learning — Main Stylesheet
   ═══════════════════════════════════════════ */

:root {
  --blue-50:  #eff6ff;
  --blue-100: #dbeafe;
  --blue-200: #bfdbfe;
  --blue-400: #60a5fa;
  --blue-500: #3b82f6;
  --blue-600: #2563eb;
  --blue-700: #1d4ed8;
  --blue-800: #1e40af;
  --blue-900: #1e3a8a;
  --white:    #ffffff;
  --gray-50:  #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --shadow-sm: 0 2px 8px  rgba(37,99,235,0.08);
  --shadow-md: 0 8px 32px rgba(37,99,235,0.12);
  --shadow-lg: 0 20px 60px rgba(37,99,235,0.18);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Plus Jakarta Sans', sans-serif;
  background: var(--blue-50);
  color: var(--gray-800);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── PAGE TRANSITIONS ── */
.page { display: none; animation: fadeSlideIn 0.45s cubic-bezier(.4,0,.2,1); }
.page.active { display: block; }
@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ══════════════════════════════
   HEADER
══════════════════════════════ */
header {
  background: var(--white);
  border-bottom: 1.5px solid var(--blue-100);
  padding: 0 32px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 20px rgba(37,99,235,0.07);
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  cursor: pointer;
  min-width: 0;
  flex-shrink: 1;
}
.logo-img {
  height: 42px;
  width: auto;
  border-radius: var(--radius-sm);
  display: block;
  flex-shrink: 0;
}
.logo-fallback {
  width: 42px; height: 42px;
  background: var(--blue-100);
  border: 2px dashed var(--blue-300);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  font-size: 0.6rem;
  font-weight: 800;
  color: var(--blue-400);
  letter-spacing: 0.5px;
}
.logo-text {
  font-family: 'Sora', sans-serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--blue-700);
  letter-spacing: -0.3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.logo-text span { color: var(--blue-400); }
.header-right { display: flex; align-items: center; gap: 14px; }

.user-badge {
  display: none;
  align-items: center;
  background: var(--blue-50);
  border: 1.5px solid var(--blue-200);
  border-radius: 50%;
  padding: 0;
  width: 36px;
  height: 36px;
  justify-content: center;
}
.user-badge.visible { display: flex; }
.user-avatar {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--blue-600), var(--blue-400));
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: white;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}
.btn-logout {
  display: none;
  background: none;
  border: 1.5px solid var(--gray-200);
  border-radius: 50%;
  width: 36px;
  height: 36px;
  padding: 0;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
  color: var(--gray-500);
  flex-shrink: 0;
}
.btn-logout svg { width: 16px; height: 16px; }
.btn-logout.visible { display: flex; }
.btn-logout:hover { border-color: var(--blue-400); color: var(--blue-600); background: var(--blue-50); }

/* ── SECTION CARDS ── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  max-width: 1000px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}
.section-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  border: 1.5px solid var(--blue-100);
  cursor: pointer;
  transition: transform 0.25s cubic-bezier(.4,0,.2,1), box-shadow 0.25s, border-color 0.25s;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  min-height: 220px;
}
.section-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--blue-600) 0%, var(--blue-400) 100%);
  opacity: 0;
  transition: opacity 0.3s;
  border-radius: inherit;
}
.section-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--blue-300); }
.section-card:hover::before { opacity: 0.04; }
.section-card:active { transform: translateY(-2px); }

.card-icon-wrap {
  width: 56px; height: 56px;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}
/* pushes card-body to the bottom */
.card-body {
  margin-top: auto;
  padding-top: 20px;
  text-align: left;
}
.card-badge {
  position: absolute;
  top: 16px; right: 16px;
  border-radius: 999px;
  padding: 3px 10px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.3px;
}
.card-title {
  font-family: 'Sora', sans-serif;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--gray-800);
  margin-bottom: 6px;
}
.card-subtitle {
  font-size: 0.83rem;
  color: var(--gray-500);
  line-height: 1.55;
}

/* card color variants — all icons on blue background */
.card-c1 .card-icon-wrap { background: var(--blue-600); }
.card-c2 .card-icon-wrap { background: var(--blue-600); }
.card-c3 .card-icon-wrap { background: var(--blue-600); }
.card-c4 .card-icon-wrap { background: var(--blue-600); }
.card-icon-wrap { filter: brightness(0) invert(1); }
.card-c1 .card-badge { background: #dbeafe; color: #2563eb; }
.card-c2 .card-badge { background: #dcfce7; color: #16a34a; }
.card-c3 .card-badge { background: #fef9c3; color: #ca8a04; }
.card-c4 .card-badge { background: #fce7f3; color: #db2777; }

/* ══════════════════════════════
   LOGIN PAGE
══════════════════════════════ */
.login-wrap {
  min-height: calc(100vh - 68px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 16px;
  background: linear-gradient(160deg, var(--blue-50) 0%, #e0eaff 100%);
}
.login-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: 48px 44px;
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow-lg);
  border: 1.5px solid var(--blue-100);
}
/* login section title — same style as coursesTitle */
.login-title {
  font-family: 'Sora', sans-serif;
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--gray-800);
  letter-spacing: -0.5px;
  margin-bottom: 10px;
}
.login-card p.sub {
  font-size: 0.88rem;
  color: var(--gray-500);
  margin-bottom: 28px;
}
.access-note {
  display: block;
  margin-top: 16px;
  font-size: 0.78rem;
  color: var(--gray-400);
  line-height: 1.5;
  text-align: center;
}
.form-group { margin-bottom: 20px; }
.form-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--gray-600);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.form-input {
  width: 100%;
  padding: 13px 16px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--gray-200);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.95rem;
  color: var(--gray-800);
  background: var(--gray-50);
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}
.form-input:focus {
  border-color: var(--blue-500);
  box-shadow: 0 0 0 3px rgba(59,130,246,0.12);
  background: white;
}
.form-input::placeholder { color: var(--gray-400); }
.btn-login {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, var(--blue-600), var(--blue-500));
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 16px rgba(37,99,235,0.3);
  letter-spacing: 0.2px;
  margin-top: 8px;
}
.btn-login:hover  { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(37,99,235,0.38); }
.btn-login:active { transform: translateY(0); }

.error-msg {
  display: none;
  background: #fef2f2;
  border: 1.5px solid #fecaca;
  color: #dc2626;
  border-radius: var(--radius-sm);
  padding: 11px 14px;
  font-size: 0.84rem;
  font-weight: 600;
  margin-top: 16px;
  text-align: center;
}
.error-msg.show { display: block; animation: shake 0.35s ease; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  20%     { transform: translateX(-6px); }
  60%     { transform: translateX(6px); }
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 24px;
  color: var(--blue-500);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: gap 0.2s, color 0.2s;
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
}
.back-link:hover { color: var(--blue-700); gap: 9px; }

/* ══════════════════════════════
   COURSES PAGE
══════════════════════════════ */
.courses-wrap {
  max-width: 900px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}
.courses-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 40px;
}
.courses-header-left h2 {
  font-family: 'Sora', sans-serif;
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--gray-800);
  letter-spacing: -0.5px;
  margin-bottom: 6px;
}
.courses-header-left p { font-size: 0.9rem; color: var(--gray-500); }
/* category block */
.cat-block {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1.5px solid var(--blue-100);
  overflow: hidden;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
  animation: fadeSlideIn 0.4s ease both;
}
.cat-block:nth-child(2) { animation-delay: 0.08s; }
.cat-block:nth-child(3) { animation-delay: 0.16s; }

.cat-header {
  background: linear-gradient(90deg, var(--blue-600) 0%, var(--blue-500) 100%);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.cat-header .cat-icon { font-size: 1.1rem; filter: brightness(0) invert(1); }
.cat-header h3 {
  font-family: 'Sora', sans-serif;
  font-size: 1rem;
  font-weight: 700;
  color: white;
  letter-spacing: 0.2px;
}
.cat-header .cat-count {
  margin-left: auto;
  background: rgba(255,255,255,0.2);
  color: white;
  border-radius: 999px;
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 700;
}

/* course table */
.course-table { width: 100%; border-collapse: collapse; }
.course-table thead tr {
  background: var(--blue-50);
  border-bottom: 1.5px solid var(--blue-100);
}
.course-table th {
  padding: 11px 20px;
  text-align: left;
  font-size: 0.73rem;
  font-weight: 800;
  color: var(--blue-600);
  letter-spacing: 0.8px;
  text-transform: uppercase;
}
.course-table th.right,
.course-table td.right { text-align: right; }
.course-table tbody tr {
  border-bottom: 1px solid var(--gray-100);
  transition: background 0.15s;
}
.course-table tbody tr:last-child { border-bottom: none; }
.course-table tbody tr:hover { background: var(--blue-50); }
.course-table td {
  padding: 14px 20px;
  font-size: 0.9rem;
  color: var(--gray-700);
  vertical-align: middle;
}
.course-num {
  font-weight: 800;
  color: var(--blue-500);
  font-variant-numeric: tabular-nums;
  font-size: 0.85rem;
  background: var(--blue-50);
  border-radius: 6px;
  padding: 3px 8px;
}
.course-name { font-weight: 600; color: var(--gray-800); }
.btn-join {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--blue-600);
  color: white;
  border-radius: var(--radius-sm);
  padding: 8px 16px;
  font-size: 0.8rem;
  font-weight: 700;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s, box-shadow 0.15s;
  letter-spacing: 0.2px;
  cursor: pointer;
  border: none;
  font-family: inherit;
}
.btn-join:hover { background: var(--blue-700); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,0.25); }
.btn-join svg { width: 13px; height: 13px; fill: none; stroke: white; stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }

/* ── STATS ROW ── */
.stats-row {
  display: flex;
  gap: 16px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}
.stat-chip {
  background: var(--white);
  border: 1.5px solid var(--blue-100);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  flex: 1;
  min-width: 120px;
  box-shadow: var(--shadow-sm);
}
.stat-chip .val {
  font-family: 'Sora', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--blue-600);
  line-height: 1;
  margin-bottom: 4px;
}
.stat-chip .lbl {
  font-size: 0.75rem;
  color: var(--gray-500);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* ══════════════════════════════
   RESPONSIVE
══════════════════════════════ */
@media (max-width: 600px) {
  header { padding: 0 14px; gap: 8px; }
  .logo-text { font-size: 0.95rem; }
  .header-right { gap: 8px; }
  .login-card { padding: 36px 24px; }
  .courses-wrap { padding: 32px 16px 60px; }
  .course-table th, .course-table td { padding: 12px 12px; }
  .cards-grid { gap: 16px; padding: 32px 16px 60px; }
}