@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&display=swap');

/* ═══════════════════════ DESIGN TOKENS ═══════════════════════ */
:root {
  /* Light mode (Study.com inspired) */
  --bg: #f3f4f6;
  --bg-gradient: linear-gradient(160deg, #f8fafc 0%, #e2e8f0 100%);
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --surface-3: #e2e8f0;
  --border: rgba(15, 23, 42, 0.08);
  --border-strong: rgba(15, 23, 42, 0.16);
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent: #2563eb; /* Trustworthy blue */
  --accent-pressed: #1d4ed8;
  --accent-2: #16a34a; /* Study green */
  --accent-purple: #7c3aed;
  --accent-orange: #ea580c; /* Warm saffron/orange */
  --danger: #dc2626;
  --warning: #ca8a04;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.03);
  --shadow: 0 4px 20px rgba(15,23,42,0.06), 0 2px 6px rgba(15,23,42,0.04);
  --shadow-lg: 0 16px 48px rgba(15,23,42,0.1), 0 6px 16px rgba(15,23,42,0.06);
  --radius: 16px;
  --radius-sm: 12px;
  --radius-xs: 8px;
  --nav-bg: rgba(255,255,255,0.85);
  --nav-border: rgba(15,23,42,0.06);
  --glass-bg: rgba(255,255,255,0.75);
  --glass-border: rgba(15,23,42,0.06);
  --input-bg: rgba(15,23,42,0.04);
  --input-border: rgba(15,23,42,0.12);
  --input-focus: rgba(37,99,235,0.25);
  /* Compat aliases used in inline styles */
  --primary-glow: #2563eb;
  --secondary-glow: #16a34a;
  --text-main: #0f172a;
  --bg-dark: #f3f4f6;
  --success: #16a34a;
}

[data-theme="dark"] {
  /* Premium Dark Mode (Deep Slate/Navy) */
  --bg: #0b0f19;
  --bg-gradient: linear-gradient(160deg, #0f172a 0%, #0b0f19 100%);
  --surface: #1e293b;
  --surface-2: #334155;
  --surface-3: #475569;
  --border: rgba(255,255,255,0.08);
  --border-strong: rgba(255,255,255,0.16);
  --text: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --accent: #3b82f6; /* Vibrant active blue */
  --accent-pressed: #60a5fa;
  --accent-2: #4ade80;
  --accent-purple: #a78bfa;
  --accent-orange: #f97316;
  --danger: #f87171;
  --warning: #facc15;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.5);
  --shadow: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.6);
  --nav-bg: rgba(15,23,42,0.85);
  --nav-border: rgba(255,255,255,0.06);
  --glass-bg: rgba(30,41,59,0.75);
  --glass-border: rgba(255,255,255,0.08);
  --input-bg: rgba(255,255,255,0.06);
  --input-border: rgba(255,255,255,0.14);
  --input-focus: rgba(59,130,246,0.25);
  --primary-glow: #3b82f6;
  --secondary-glow: #4ade80;
  --text-main: #f8fafc;
  --bg-dark: #0b0f19;
  --success: #4ade80;
}

/* ═══════════════════════ BASE ═══════════════════════ */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-font-smoothing: antialiased; scroll-behavior: smooth; }

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, 'SF Pro Display', 'SF Pro Text', 'Inter', BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.5;
  background: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text);
  min-height: 100vh;
  transition: background 0.25s ease, color 0.25s ease;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.4px;
  color: var(--text);
  margin-top: 0;
}

a { color: var(--accent); text-decoration: none; }
a:hover { opacity: 0.8; }
p { color: var(--text-secondary); }
small { color: var(--text-muted); font-size: 0.85em; }
code { font-family: 'SF Mono', 'Menlo', monospace; font-size: 0.88em; }

/* ═══════════════════════ LAYOUT ═══════════════════════ */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
}
.content { width: 100%; }
.mt-4 { margin-top: 24px; }
.mb-4 { margin-bottom: 24px; }
.text-center { text-align: center; }

/* ═══════════════════════ NAVBAR ═══════════════════════ */
.fancy-navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 24px;
  height: 56px;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--nav-border);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background 0.25s ease;
}

.fancy-navbar h2 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  background: none !important;
  -webkit-text-fill-color: var(--text) !important;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.88rem;
  padding: 6px 10px;
  border-radius: 8px;
  transition: color 0.15s, background 0.15s;
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--surface-3);
  opacity: 1;
}

.nav-links a.active {
  color: var(--accent);
  background: rgba(0,113,227,0.08);
  font-weight: 600;
}

[data-theme="dark"] .nav-links a.active {
  background: rgba(41,151,255,0.12);
}

/* Theme toggle button in navbar */
.theme-toggle {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.15s;
  margin-left: 6px;
  padding: 0;
  flex-shrink: 0;
}
.theme-toggle:hover { background: var(--surface-3); opacity: 1; }

.lh-signout {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 4px 12px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
  margin-left: 6px;
  white-space: nowrap;
  flex-shrink: 0;
}
.lh-signout:hover { background: #fee2e2; border-color: #fca5a5; color: #dc2626; }

/* ═══════════════════════ HAMBURGER MENU ═══════════════════════ */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  flex-direction: column;
  gap: 5px;
  z-index: 200;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2.5px;
  background: var(--text);
  border-radius: 3px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  transform-origin: center;
}
.hamburger.active span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.active span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

@media (max-width: 768px) {
  .hamburger { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 12px 20px;
    gap: 2px;
    box-shadow: var(--shadow-lg);
    z-index: 150;
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: 12px 16px;
    width: 100%;
    font-size: 0.95rem;
  }
  .nav-links .theme-toggle {
    margin: 8px 0 0 0;
    align-self: flex-start;
  }
  .fancy-navbar { position: relative; }
}

/* ═══════════════════════ CARDS / PANELS ═══════════════════════ */
.glass-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  transition: background 0.25s ease, border-color 0.25s ease;
}

.generator-section { margin-bottom: 24px; }
.library-section   { margin-bottom: 24px; }

/* ═══════════════════════ BUTTONS ═══════════════════════ */
button, .btn, [class*="btn-"] {
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: none;
  transition: transform 0.12s ease, opacity 0.12s ease, background 0.15s ease, box-shadow 0.15s ease;
}

button:hover:not(:disabled), .btn:hover:not(:disabled) { opacity: 0.86; }

button:active:not(:disabled), .btn:active:not(:disabled),
[class*="btn-"]:active:not(:disabled) {
  transform: scale(0.96) !important;
  opacity: 0.72 !important;
  transition: transform 0.06s, opacity 0.06s !important;
}

button:disabled, .btn:disabled {
  opacity: 0.38;
  cursor: not-allowed;
}

/* Click ripple */
button::after, .btn::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: rgba(255,255,255,0.2);
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}
button:active::after, .btn:active::after { opacity: 1; transition: opacity 0s; }

.btn {
  padding: 10px 20px;
  font-size: 0.93rem;
  gap: 7px;
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(0,113,227,0.3);
}
.btn-primary:hover:not(:disabled) { opacity: 1; background: var(--accent-pressed); }

.btn-secondary {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover:not(:disabled) { opacity: 1; background: var(--surface-3); }

.btn-success {
  background: var(--accent-2);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(52,199,89,0.3);
}
.btn-success:hover:not(:disabled) { opacity: 1; }

.btn-accent {
  background: var(--accent-orange);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(255,159,10,0.3);
}

.btn-danger {
  background: var(--danger);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(255,59,48,0.3);
}

.btn-glow {
  border-radius: var(--radius-sm);
  font-weight: 600;
}

/* ═══════════════════════ FORMS ═══════════════════════ */
label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
  letter-spacing: 0.01em;
}

input, select, textarea {
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-family: inherit;
  font-size: 0.93rem;
  transition: border-color 0.15s, box-shadow 0.15s, background 0.25s;
  width: 100%;
  box-sizing: border-box;
  margin-top: 4px;
  appearance: none;
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 10 10'%3E%3Cpath fill='%236e6e73' d='M5 7L0 2h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
  cursor: pointer;
}
[data-theme="dark"] select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 10 10'%3E%3Cpath fill='%23ababaf' d='M5 7L0 2h10z'/%3E%3C/svg%3E");
}

textarea { resize: vertical; }

input::placeholder, textarea::placeholder { color: var(--text-muted); }

input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--input-focus);
  background: var(--surface);
}

/* Ensure text is readable in select options on dark mode */
[data-theme="dark"] option {
  background: var(--surface-2);
  color: var(--text);
}

.form-group { margin-bottom: 16px; }
.form-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 16px; }

/* ═══════════════════════ UPLOAD ZONE ═══════════════════════ */
.upload-zone, .file-upload {
  border: 2px dashed var(--border-strong);
  background: var(--input-bg);
  padding: 32px;
  border-radius: var(--radius);
  text-align: center;
  transition: all 0.2s ease;
  cursor: pointer;
  color: var(--text-secondary);
}
.upload-zone:hover, .file-upload:hover {
  background: rgba(0,113,227,0.05);
  border-color: var(--accent);
  color: var(--accent);
}
[data-theme="dark"] .upload-zone:hover, [data-theme="dark"] .file-upload:hover {
  background: rgba(41,151,255,0.08);
}

/* ═══════════════════════ ALERTS ═══════════════════════ */
.alert {
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  border: 1px solid transparent;
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--text);
}
.alert-info {
  background: rgba(0,113,227,0.08);
  border-color: rgba(0,113,227,0.2);
  color: var(--accent);
}
.alert-success {
  background: rgba(52,199,89,0.08);
  border-color: rgba(52,199,89,0.25);
  color: #1a8f3a;
}
.alert-error {
  background: rgba(255,59,48,0.08);
  border-color: rgba(255,59,48,0.25);
  color: var(--danger);
}
[data-theme="dark"] .alert-success { color: #30d158; }
[data-theme="dark"] .alert-info    { color: #64b5ff; }
[data-theme="dark"] .alert-error   { color: #ff6b6b; }

/* ═══════════════════════ LOADING SPINNER ═══════════════════════ */
.loading {
  display: inline-block;
  width: 17px;
  height: 17px;
  border: 2.5px solid var(--border-strong);
  border-radius: 50%;
  border-top-color: var(--accent);
  animation: spin 0.75s linear infinite;
  vertical-align: middle;
  margin-right: 6px;
  flex-shrink: 0;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ═══════════════════════ STATUS INDICATORS ═══════════════════════ */
.status-indicator {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  margin-right: 6px;
  vertical-align: middle;
}
.status-connected    { background: var(--accent-2); box-shadow: 0 0 6px var(--accent-2); }
.status-disconnected { background: var(--danger);   box-shadow: 0 0 6px var(--danger); }

/* ═══════════════════════ TABLES ═══════════════════════ */
table { width: 100%; border-collapse: collapse; }

th {
  background: var(--surface-2);
  color: var(--text-secondary);
  text-transform: uppercase;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

td {
  padding: 13px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  vertical-align: middle;
  font-size: 0.92rem;
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--surface-2); }

/* ═══════════════════════ QUIZ ═══════════════════════ */
.quiz-container {
  max-width: 820px;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin: 0 auto 24px auto;
  width: 100%;
  position: relative;
}

.progress-bar {
  width: 100%;
  height: 5px;
  background: var(--surface-2);
  border-radius: 3px;
  margin-bottom: 28px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--accent-2);
  width: 0%;
  transition: width 0.3s ease;
  border-radius: 3px;
}

.question-counter {
  text-align: center;
  margin-bottom: 18px;
  font-size: 0.9em;
  color: var(--text-muted);
  font-weight: 500;
}

.question {
  font-size: 1.22em;
  margin-bottom: 22px;
  line-height: 1.55;
  color: var(--text);
  font-weight: 600;
}

.options { display: flex; flex-direction: column; gap: 10px; }

.options button {
  padding: 13px 18px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.94em;
  text-align: left;
  background: var(--surface);
  color: var(--text);
  position: relative;
  overflow: hidden;
  transition: all 0.15s ease;
  font-weight: 500;
}

.options button:hover:not(:disabled) {
  border-color: var(--accent);
  background: rgba(0,113,227,0.04);
  transform: none;
  opacity: 1;
}
[data-theme="dark"] .options button:hover:not(:disabled) {
  background: rgba(41,151,255,0.06);
}

.options button.correct {
  background: rgba(52,199,89,0.1);
  border-color: var(--accent-2);
  color: #1a7a30;
}
[data-theme="dark"] .options button.correct { color: #30d158; background: rgba(48,209,88,0.12); }

.options button.wrong {
  background: rgba(255,59,48,0.08);
  border-color: var(--danger);
  color: var(--danger);
}

.options button:disabled { cursor: not-allowed; }

.score-display {
  position: absolute;
  top: 20px;
  right: 24px;
  background: var(--accent);
  color: white;
  padding: 6px 16px;
  border-radius: 20px;
  font-weight: 700;
  font-size: 0.88rem;
}

.navigation { display: flex; justify-content: center; gap: 12px; margin-top: 28px; }

.results { text-align: center; padding: 40px 20px; }
.results h2 { color: var(--text); margin-bottom: 16px; font-size: 2em; }

.final-score {
  font-size: 1.3em;
  margin-bottom: 28px;
  padding: 20px;
  background: var(--accent);
  color: white;
  border-radius: var(--radius-sm);
}

/* ═══════════════════════ QUESTION PREVIEW (GENERATE PAGE) ═══════════════════════ */
.question-item {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 18px;
  margin-bottom: 12px;
}
.question-item h4 { color: var(--text-muted); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 8px; font-weight: 700; }
.question-options { display: flex; flex-direction: column; gap: 6px; margin: 10px 0; }
.option {
  padding: 9px 14px;
  border-radius: 8px;
  font-size: 0.91rem;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
}
.option.correct { background: rgba(52,199,89,0.1); border-color: var(--accent-2); color: #1a7a30; font-weight: 600; }
[data-theme="dark"] .option.correct { color: #30d158; background: rgba(48,209,88,0.12); }

/* ═══════════════════════ ADMIN ═══════════════════════ */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin-bottom: 24px; }
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 24px;
  border-radius: var(--radius-sm);
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.stat-number { font-size: 2.4em; font-weight: 800; color: var(--accent); margin-bottom: 8px; }

.admin-subnav {
  display: flex;
  gap: 6px;
  margin-bottom: 20px;
  background: var(--surface-2);
  padding: 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.admin-subnav button {
  flex: 1;
  padding: 8px 12px;
  border-radius: 7px;
  border: none;
  font-weight: 600;
  font-size: 0.86rem;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
}
.admin-subnav button:hover { background: var(--surface-3); color: var(--text); opacity: 1; }
.admin-subnav button.active {
  background: var(--surface);
  color: var(--accent);
  box-shadow: var(--shadow-sm);
}

/* ═══════════════════════ PDF / CONTENT SECTION ═══════════════════════ */
.pdf-section {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 20px;
  border-radius: var(--radius);
  margin-top: 20px;
  box-shadow: var(--shadow-sm);
}
.pdf-upload { margin-bottom: 20px; text-align: center; }
#pdfViewer { width: 100%; height: 600px; border: 1px solid var(--border); border-radius: 8px; }

/* ═══════════════════════ ACTION BUTTONS ═══════════════════════ */
.action-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

/* ═══════════════════════ FLASHCARDS ═══════════════════════ */
.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.55s cubic-bezier(0.4,0,0.2,1);
  transform-style: preserve-3d;
}
.flashcard-flipped .flashcard-inner { transform: rotateY(180deg); }

.flashcard-front, .flashcard-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  box-sizing: border-box;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow);
}
.flashcard-front { color: var(--text); font-weight: 700; font-size: 1.3rem; }
.flashcard-back  { color: var(--text-secondary); transform: rotateY(180deg); font-size: 1.05rem; line-height: 1.55; }

/* ═══════════════════════ SLIDES / VIDEO PLAYER ANIMATION ═══════════════════════ */
@keyframes slidesBarPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}
#slidesGenProgressBar.slides-gen-active,
#flashGenProgressBar.flash-gen-active {
  animation: slidesBarPulse 1.4s ease-in-out infinite;
}

/* ═══════════════════════ PODCAST TRANSCRIPT ═══════════════════════ */
.podcast-line-host {
  color: var(--accent);
  font-weight: 700;
}
.podcast-line-expert {
  color: var(--accent-2);
  font-weight: 700;
}

/* ═══════════════════════ RESPONSIVE ═══════════════════════ */
@media (max-width: 720px) {
  .fancy-navbar { padding: 0 14px; height: 52px; }
  .nav-links { gap: 2px; }
  .nav-links a { font-size: 0.8rem; padding: 5px 7px; }
  .container { padding: 16px; }
  .glass-panel { padding: 18px; border-radius: 12px; }
  .form-row { grid-template-columns: 1fr; }
  .quiz-container { padding: 20px; }
}

/* ═══════════════════════ THEME-AWARE DYNAMIC CLASSES ═══════════════════════ */
.theme-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin: 15px 0;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  color: var(--text);
  box-shadow: var(--shadow-sm);
  position: relative;
}
.theme-card:hover {
  transform: translateY(-1px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
}
.theme-card h4 {
  color: var(--text);
  margin-top: 0;
  margin-bottom: 8px;
  font-weight: 700;
}
.theme-card p {
  color: var(--text-secondary);
  margin: 8px 0;
}
.theme-card small {
  color: var(--text-muted);
}
.theme-card-success { border-left: 4px solid var(--accent-2) !important; }
.theme-card-warning { border-left: 4px solid var(--accent-orange) !important; }
.theme-card-danger { border-left: 4px solid var(--danger) !important; }

.theme-option {
  padding: 11px 15px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 0.92rem;
  margin: 8px 0;
  transition: all 0.15s ease;
}
.theme-option.correct {
  background: rgba(22, 163, 74, 0.12) !important;
  border-color: var(--accent-2) !important;
  color: var(--text) !important;
  font-weight: 600;
}
[data-theme="dark"] .theme-option.correct {
  background: rgba(74, 222, 128, 0.15) !important;
  color: #4ade80 !important;
}
.theme-option.wrong {
  background: rgba(220, 38, 38, 0.12) !important;
  border-color: var(--danger) !important;
  color: var(--text) !important;
}
[data-theme="dark"] .theme-option.wrong {
  background: rgba(248, 113, 113, 0.15) !important;
  color: #f87171 !important;
}
.theme-option.muted {
  color: var(--text-secondary);
}

.theme-explanation {
  padding: 12px 14px;
  background: rgba(37, 99, 235, 0.06);
  border-radius: 8px;
  border-left: 3px solid var(--accent);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-top: 12px;
  color: var(--text);
}
[data-theme="dark"] .theme-explanation {
  background: rgba(59, 130, 246, 0.1) !important;
}

/* ═══════════════════════ LANDING PAGE REDESIGN (STUDY.COM STYLE) ═══════════════════════ */
.landing-hero-bg {
  background: #00233e;
  color: #ffffff;
  padding: 80px 0;
  width: 100vw;
  position: relative;
  left: 50%;
  right: 50%;
  margin-left: -50vw;
  margin-right: -50vw;
  box-sizing: border-box;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
[data-theme="dark"] .landing-hero-bg {
  background: #070b13;
  border-bottom-color: rgba(255, 255, 255, 0.05);
}

.landing-hero-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
  text-align: left;
}

.landing-info-column {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.landing-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: 30px;
  margin-bottom: 24px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: 'Plus Jakarta Sans', sans-serif;
}

.landing-info-column h1 {
  font-family: 'Plus Jakarta Sans', -apple-system, sans-serif;
  font-size: clamp(2.8rem, 6.2vw, 4.4rem);
  line-height: 1.1;
  margin-top: 0;
  margin-bottom: 24px;
  letter-spacing: -2px;
  font-weight: 900;
  color: #ffffff;
}

.landing-lead {
  font-size: 1.15rem;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 36px;
  max-width: 600px;
}

.feature-bullets {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
}

.feature-bullet {
  display: flex;
  gap: 18px;
  align-items: center;
  padding: 18px 22px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-bullet:hover {
  transform: translateX(6px);
  background: rgba(255, 255, 255, 0.09);
  border-color: rgba(255, 255, 255, 0.15);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.bullet-icon {
  font-size: 1.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  flex-shrink: 0;
}

.feature-bullet h4 {
  margin: 0 0 4px 0;
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  font-family: 'Plus Jakarta Sans', sans-serif;
}

.feature-bullet p {
  margin: 0;
  font-size: 0.88rem;
  color: rgba(255, 255, 255, 0.75);
  line-height: 1.45;
}

.landing-login-column {
  display: flex;
  justify-content: center;
  width: 100%;
}

/* On-page login card style override */
#lh-login-card {
  border-radius: 24px !important;
  border: 1px solid rgba(255, 255, 255, 0.1) !important;
  background: rgba(15, 23, 42, 0.75) !important;
  backdrop-filter: blur(20px) !important;
  -webkit-backdrop-filter: blur(20px) !important;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.35) !important;
  padding: 44px 38px !important;
  color: #ffffff !important;
}

#lh-login-card h2 {
  color: #ffffff !important;
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 1.6rem;
}

#lh-login-card .lh-sub {
  color: rgba(255, 255, 255, 0.6) !important;
}

#lh-login-card label {
  color: rgba(255, 255, 255, 0.5) !important;
}

#lh-login-card input {
  border-radius: 12px !important;
  border: 1px solid rgba(255, 255, 255, 0.12) !important;
  background: rgba(255, 255, 255, 0.06) !important;
  color: #ffffff !important;
  transition: all 0.2s ease !important;
}
#lh-login-card input:focus {
  border-color: var(--accent) !important;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25) !important;
  background: rgba(255, 255, 255, 0.1) !important;
}
#lh-login-card input::placeholder {
  color: rgba(255, 255, 255, 0.35);
}

#lh-login-btn {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-pressed) 100%) !important;
  border-radius: 12px !important;
  font-weight: 700 !important;
  letter-spacing: -0.2px;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3) !important;
  transition: all 0.2s ease !important;
}
#lh-login-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4) !important;
}

/* Fancy navbar overrides */
.fancy-navbar {
  height: 72px !important;
  border-bottom: 1px solid var(--nav-border);
  transition: all 0.3s ease;
}

.nav-links a {
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 600;
  font-size: 0.9rem;
  padding: 8px 14px;
  border-radius: 10px;
}

.fancy-navbar .unauth-only {
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 700;
  border: 2px solid var(--accent);
  color: var(--accent);
  background: transparent;
  border-radius: 10px;
  padding: 6px 18px;
  transition: all 0.2s ease;
  text-decoration: none;
  font-size: 0.88rem;
}
.fancy-navbar .unauth-only:hover {
  background: var(--accent);
  color: #ffffff;
  opacity: 1;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}
[data-theme="dark"] .fancy-navbar .unauth-only {
  border-color: #60a5fa;
  color: #60a5fa;
}
[data-theme="dark"] .fancy-navbar .unauth-only:hover {
  background: #60a5fa;
  color: #0b0f19;
}

/* Mockup showcase */
.hero-mockup-wrapper {
  margin-top: 96px;
  margin-bottom: 64px;
  text-align: center;
  position: relative;
}

.hero-mockup-wrapper::before {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 80%; height: 80%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.08), transparent 70%);
  z-index: -1;
  pointer-events: none;
}
[data-theme="dark"] .hero-mockup-wrapper::before {
  background: radial-gradient(circle, rgba(96, 165, 250, 0.12), transparent 70%);
}

.mockup-header-text h3 {
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 2rem;
  font-weight: 800;
  margin: 0 0 10px 0;
  letter-spacing: -0.8px;
}

.mockup-header-text p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin: 0 auto 36px auto;
  max-width: 500px;
}

.hero-mockup {
  max-width: 960px;
  margin: 0 auto;
  border-radius: 20px;
  padding: 10px;
  background: rgba(255, 255, 255, 0.3);
  border: 1px solid rgba(15, 23, 42, 0.06);
  box-shadow: 0 30px 70px rgba(15, 23, 42, 0.12);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
[data-theme="dark"] .hero-mockup {
  background: rgba(30, 41, 59, 0.3);
  border-color: rgba(255, 255, 255, 0.06);
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.5);
}

.hero-mockup:hover {
  transform: translateY(-6px);
  box-shadow: 0 40px 90px rgba(15, 23, 42, 0.18);
}
[data-theme="dark"] .hero-mockup:hover {
  box-shadow: 0 40px 90px rgba(0, 0, 0, 0.65);
}

.hero-mockup img {
  border-radius: 12px;
}

/* Hide auth nav links by default */
.auth-only {
  display: none !important;
}

/* Adjust responsive styles */
@media (max-width: 900px) {
  .landing-hero-bg { padding: 48px 0; }
  .landing-hero-container {
    grid-template-columns: 1fr;
    gap: 36px;
    padding: 0 20px;
  }
  .landing-info-column {
    align-items: center;
    text-align: center;
  }
  .landing-info-column h1 {
    font-size: clamp(2rem, 8vw, 2.6rem);
    letter-spacing: -1px;
  }
  .landing-lead {
    font-size: 1rem;
    margin-bottom: 24px;
  }
  .feature-bullet {
    text-align: left;
    width: 100%;
    padding: 14px 16px;
  }
  .feature-bullet h4 { font-size: 0.95rem; }
  .feature-bullet p { font-size: 0.82rem; }
  .landing-login-column {
    max-width: 400px;
    margin: 0 auto;
  }
  #lh-login-card {
    padding: 32px 24px !important;
  }
  .hero-mockup-wrapper {
    margin-top: 56px;
    margin-bottom: 40px;
  }
  .mockup-header-text h3 { font-size: 1.5rem; }
  .mockup-header-text p { font-size: 0.95rem; }
  .hero-mockup {
    max-width: 100%;
    border-radius: 14px;
    padding: 6px;
  }
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .landing-hero-bg { padding: 32px 0; }
  .landing-hero-container { gap: 28px; padding: 0 16px; }
  .landing-info-column h1 { font-size: 1.9rem; }
  .landing-lead { font-size: 0.92rem; }
  .landing-badge { font-size: 0.72rem; padding: 5px 12px; }
  .bullet-icon { width: 38px; height: 38px; font-size: 1.3rem; }
  .feature-bullet { padding: 12px 14px; gap: 14px; }
  .hero-mockup-wrapper { margin-top: 40px; margin-bottom: 32px; }
  .mockup-header-text h3 { font-size: 1.25rem; }
}