/* ==========================================================================
   STET BIHAR COMPUTER SCIENCE MASTERY PLATFORM — STYLESHEET
   Design System: Calm, Paper-Comfortable Light Theme for Long Exam Sessions
   ========================================================================== */

:root {
  /* Color Palette - Soft, Low-Glare Light Theme */
  --bg-primary: #eef1f6;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f5f7fb;
  --bg-glass: rgba(255, 255, 255, 0.92);
  --bg-glass-card: rgba(255, 255, 255, 0.9);

  --text-main: #1c2434;
  --text-muted: #5b6472;
  --text-dim: #8992a3;

  --border-color: #dde3ec;
  --border-light: rgba(15, 23, 42, 0.06);
  --border-glow: rgba(37, 99, 235, 0.3);

  --accent-blue: #2563eb;
  --accent-blue-bg: rgba(37, 99, 235, 0.1);
  --accent-indigo: #4f46e5;
  --accent-indigo-bg: rgba(79, 70, 229, 0.1);
  --accent-purple: #7c3aed;
  --accent-purple-bg: rgba(124, 58, 237, 0.1);
  --accent-green: #059669;
  --accent-green-bg: rgba(5, 150, 105, 0.1);
  --accent-amber: #b45309;
  --accent-amber-bg: rgba(180, 83, 9, 0.1);
  --accent-red: #dc2626;
  --accent-red-bg: rgba(220, 38, 38, 0.1);

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Outfit', 'Inter', sans-serif;
  --font-mono: 'Fira Code', 'SF Mono', Consolas, monospace;

  /* Consistent Spacing Scale */
  --space-2xs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 26px;

  --shadow-sm: 0 1px 3px rgba(28, 36, 52, 0.06);
  --shadow-md: 0 4px 14px rgba(28, 36, 52, 0.08);
  --shadow-lg: 0 14px 32px -8px rgba(28, 36, 52, 0.14);
  --shadow-glow: 0 6px 18px rgba(37, 99, 235, 0.22);

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

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

html, body {
  width: 100%;
  min-height: 100vh;
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection {
  background: var(--accent-blue);
  color: #ffffff;
}

button, input, select, textarea {
  font-family: inherit;
  color: inherit;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
}

/* ==========================================================================
   1. AUTHENTICATION GUARD OVERLAY
   ========================================================================== */
.guard-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: radial-gradient(circle at top right, rgba(37, 99, 235, 0.1), transparent 45%),
              radial-gradient(circle at bottom left, rgba(124, 58, 237, 0.1), transparent 45%),
              var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  backdrop-filter: blur(16px);
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.guard-overlay.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.guard-card {
  width: 100%;
  max-width: 440px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.guard-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple), var(--accent-green));
}

.guard-brand {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.guard-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  background: var(--accent-blue-bg);
  color: var(--accent-blue);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--space-sm);
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.guard-title {
  font-size: 1.6rem;
  font-weight: 800;
  font-family: var(--font-display);
  letter-spacing: -0.5px;
  margin-bottom: 6px;
}

.guard-subtitle {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.guard-form {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
}

.input-field {
  width: 100%;
  padding: 12px 16px;
  min-height: 46px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-field:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.select-field {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2094a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 40px;
}

.passcode-hint-box {
  background: var(--accent-purple-bg);
  border: 1px dashed rgba(168, 85, 247, 0.4);
  padding: 10px 14px;
  border-radius: var(--radius-md);
  font-size: 0.82rem;
  color: #6b21a8;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.btn-demo-fill {
  background: rgba(168, 85, 247, 0.3);
  border: 1px solid var(--accent-purple);
  color: #ffffff;
  padding: 5px 12px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-fast);
  white-space: nowrap;
}

.btn-demo-fill:hover {
  background: var(--accent-purple);
}

.btn-primary {
  width: 100%;
  padding: 13px 20px;
  min-height: 48px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-indigo));
  color: #ffffff;
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: var(--shadow-glow);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.btn-primary:hover {
  transform: translateY(-1px);
  opacity: 0.95;
}

.btn-primary:active {
  transform: translateY(0);
}

.guard-error {
  background: var(--accent-red-bg);
  border: 1px solid rgba(239, 68, 68, 0.4);
  color: #b91c1c;
  padding: 10px 14px;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  display: none;
}

/* ==========================================================================
   2. APP HEADER & NAVIGATION
   ========================================================================== */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  padding: 14px 24px;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.brand-section {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  flex-shrink: 0;
}

.brand-info h1 {
  font-size: 1.15rem;
  font-weight: 800;
  font-family: var(--font-display);
  letter-spacing: -0.3px;
  line-height: 1.2;
}

.brand-info p {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.header-stats {
  display: flex;
  align-items: center;
  gap: 12px;
}

.stat-chip {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
}

.stat-chip b {
  color: var(--accent-blue);
}

.user-profile-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: 30px;
  cursor: pointer;
}

.user-avatar {
  width: 28px;
  height: 28px;
  background: var(--accent-purple-bg);
  color: var(--accent-purple);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  flex-shrink: 0;
}

.user-email-text {
  font-size: 0.82rem;
  font-weight: 500;
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Mobile Hamburger Button */
.mobile-hamburger-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  padding: 8px;
}

.mobile-hamburger-btn span {
  width: 22px;
  height: 2px;
  background-color: var(--text-main);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* Mobile Navigation Drawer */
.mobile-drawer-backdrop {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease;
}

.mobile-drawer-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.mobile-nav-drawer {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 290px;
  max-width: 85vw;
  z-index: 2001;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  padding: 24px 20px;
  overflow-y: auto;
}

.mobile-nav-drawer.active {
  transform: translateX(0);
}

.drawer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--border-color);
}

.drawer-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.3rem;
  cursor: pointer;
  padding: 6px;
}

.drawer-user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 14px;
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
}

.drawer-nav-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.drawer-nav-btn {
  width: 100%;
  text-align: left;
  padding: 12px 16px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: var(--transition-fast);
}

.drawer-nav-btn:hover, .drawer-nav-btn.active {
  background: var(--accent-blue-bg);
  border-color: rgba(59, 130, 246, 0.3);
  color: var(--accent-blue);
}

.drawer-footer {
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-color);
}

/* Tab Bar Desktop */
.nav-tabs-bar {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 24px;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-tabs-bar::-webkit-scrollbar {
  display: none;
}

.nav-tabs-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  gap: 6px;
}

.nav-tab-btn {
  padding: 14px 20px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-tab-btn:hover {
  color: var(--text-main);
}

.nav-tab-btn.active {
  color: var(--accent-blue);
  border-bottom-color: var(--accent-blue);
}

.tab-badge {
  background: var(--accent-blue-bg);
  color: var(--accent-blue);
  font-size: 0.72rem;
  padding: 2px 7px;
  border-radius: 10px;
  font-weight: 700;
}

/* Mobile Bottom Navigation Bar */
.mobile-bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 1500;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--border-color);
  padding: 10px 12px 14px;
  justify-content: space-around;
  align-items: center;
  box-shadow: 0 -4px 16px rgba(28, 36, 52, 0.08);
}

.bottom-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  padding: 4px 10px;
  transition: color var(--transition-fast);
}

.bottom-nav-item .icon {
  font-size: 1.25rem;
}

.bottom-nav-item.active {
  color: var(--accent-blue);
}

/* ==========================================================================
   3. MAIN APP CONTENT LAYOUT (WITH HARMONIZED SPACING)
   ========================================================================== */
.main-content-wrapper {
  max-width: 1400px;
  margin: 0 auto;
  padding: 32px 24px 120px;
}

.app-screen {
  display: none;
  animation: fadeIn 0.3s ease;
}

.app-screen.active {
  display: block;
}

.screen-header {
  margin-bottom: var(--space-xl);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.screen-title {
  font-size: 1.65rem;
  font-weight: 800;
  font-family: var(--font-display);
  letter-spacing: -0.5px;
}

.screen-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Cards Base */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-md);
}

/* ==========================================================================
   4. DASHBOARD SCREEN
   ========================================================================== */
.hero-readiness-card {
  background: linear-gradient(135deg, #ffffff, #f4f7fd),
              radial-gradient(circle at top right, rgba(37, 99, 235, 0.12), transparent 60%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 40px;
  margin-bottom: var(--space-xl);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  box-shadow: var(--shadow-lg);
}

.hero-text h2 {
  font-size: 1.55rem;
  font-weight: 800;
  font-family: var(--font-display);
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}

.hero-text p {
  color: var(--text-muted);
  font-size: 0.94rem;
  max-width: 540px;
  margin-bottom: 24px;
  line-height: 1.6;
}

.readiness-ring-wrap {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--bg-secondary) 55%, transparent 56%),
              conic-gradient(var(--accent-blue) calc(var(--pct, 0) * 1%), var(--border-color) 0);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 0 16px rgba(37, 99, 235, 0.16);
}

.readiness-ring-val {
  font-size: 1.6rem;
  font-weight: 800;
  font-family: var(--font-display);
  color: var(--accent-blue);
  text-align: center;
}

.readiness-ring-val span {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  display: block;
}

.quick-actions-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.action-btn {
  padding: 12px 22px;
  min-height: 46px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: var(--transition-fast);
}

.action-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

.action-btn.primary-action {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-indigo));
  border: none;
  color: #fff;
  box-shadow: var(--shadow-glow);
}

.action-btn.primary-action:hover {
  opacity: 0.95;
  color: #fff;
}

/* Units Grid */
.cards-grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 20px;
  margin-bottom: var(--space-xl);
}

.unit-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 12px;
}

.unit-card-title {
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.35;
}

.unit-card-count {
  font-size: 0.75rem;
  background: var(--bg-secondary);
  color: var(--text-muted);
  padding: 3px 10px;
  border-radius: 12px;
  white-space: nowrap;
}

.progress-bar-bg {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
  margin-top: 12px;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-indigo));
  border-radius: 4px;
  transition: width 0.4s ease;
}

/* ==========================================================================
   5. MOCK TESTS SCREEN
   ========================================================================== */
.mock-section-title {
  font-size: 1.2rem;
  font-weight: 800;
  font-family: var(--font-display);
  margin: 32px 0 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pyq-badge {
  background: var(--accent-purple-bg);
  color: var(--accent-purple);
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 0.72rem;
  text-transform: uppercase;
  font-weight: 800;
  letter-spacing: 0.5px;
}

.mock-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 20px;
}

.mock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
}

.mock-card.pyq-card {
  border-color: rgba(124, 58, 237, 0.3);
  background: linear-gradient(135deg, #ffffff, #f8f5fe);
}

.mock-card-meta {
  display: flex;
  gap: 14px;
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.mock-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.btn-start-mock {
  width: 100%;
  padding: 12px;
  min-height: 46px;
  background: var(--accent-blue-bg);
  border: 1px solid var(--accent-blue);
  color: var(--accent-blue);
  border-radius: var(--radius-md);
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-start-mock:hover {
  background: var(--accent-blue);
  color: #ffffff;
}

/* ==========================================================================
   PRESET 150-QUESTION FULL MOCKS — PREMIUM DESIGN STYLES
   ========================================================================== */

.mock-section-header {
  margin-top: 40px;
  margin-bottom: 24px;
}

.section-tag-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--accent-blue);
  background: var(--accent-blue-bg);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 8px;
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.mock-section-subtitle {
  font-size: 0.92rem;
  color: var(--text-muted);
  max-width: 820px;
  line-height: 1.5;
  margin-top: 4px;
  margin-bottom: 18px;
}

.mock-spec-banner {
  display: flex;
  align-items: center;
  justify-content: space-around;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.05), rgba(124, 58, 237, 0.05));
  border: 1px solid rgba(37, 99, 235, 0.15);
  border-radius: var(--radius-lg);
  padding: 16px 24px;
  margin-bottom: 24px;
  backdrop-filter: blur(8px);
}

.spec-item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.spec-icon {
  font-size: 1.4rem;
}

.spec-val {
  font-size: 1rem;
  font-weight: 800;
  color: var(--text-main);
}

.spec-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.spec-divider {
  width: 1px;
  height: 36px;
  background: var(--border-color);
}

.mock-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.mock-filter-tabs {
  display: flex;
  gap: 8px;
  background: var(--bg-card);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  flex-wrap: wrap;
}

.mock-filter-tab {
  background: transparent;
  border: none;
  padding: 8px 16px;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition-fast);
}

.mock-filter-tab:hover {
  color: var(--text-main);
  background: rgba(15, 23, 42, 0.04);
}

.mock-filter-tab.active {
  background: var(--accent-blue);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

.mock-search-wrap {
  flex: 1;
  min-width: 240px;
  max-width: 380px;
}

.mock-search-wrap input {
  padding: 9px 16px;
  font-size: 0.85rem;
  height: 40px;
}

/* Preset Mock Cards Grid */
.preset-mocks-grid {
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 22px;
}

.preset-mock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
  position: relative;
  overflow: hidden;
  transition: transform 0.22s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.22s ease, border-color 0.22s ease;
  box-shadow: var(--shadow-sm);
}

.preset-mock-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--card-accent-1, #2563eb), var(--card-accent-2, #7c3aed));
  opacity: 0.9;
}

.preset-mock-card:hover {
  transform: translateY(-4px);
  border-color: rgba(37, 99, 235, 0.35);
  box-shadow: var(--shadow-lg);
}

.preset-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.preset-idx-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.12), rgba(124, 58, 237, 0.12));
  color: var(--accent-blue);
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.preset-tier-pill {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.tier-foundational {
  background: rgba(5, 150, 105, 0.1);
  color: #059669;
  border: 1px solid rgba(5, 150, 105, 0.25);
}

.tier-standard {
  background: rgba(37, 99, 235, 0.1);
  color: #2563eb;
  border: 1px solid rgba(37, 99, 235, 0.25);
}

.tier-high-yield {
  background: rgba(124, 58, 237, 0.1);
  color: #7c3aed;
  border: 1px solid rgba(124, 58, 237, 0.25);
}

.tier-mega {
  background: rgba(217, 119, 6, 0.1);
  color: #d97706;
  border: 1px solid rgba(217, 119, 6, 0.25);
}

.preset-card-title {
  font-size: 1.18rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.35;
  margin-bottom: 6px;
  letter-spacing: -0.2px;
}

.preset-card-desc {
  font-size: 0.83rem;
  color: var(--text-muted);
  line-height: 1.45;
  margin-bottom: 14px;
}

/* Distribution bar */
.preset-dist-bar-wrap {
  margin-bottom: 14px;
}

.preset-dist-bar {
  display: flex;
  height: 6px;
  border-radius: 999px;
  overflow: hidden;
  background: var(--border-color);
  margin-bottom: 6px;
}

.dist-seg-cs {
  width: 66.67%;
  background: #2563eb;
}

.dist-seg-pedagogy {
  width: 20.0%;
  background: #7c3aed;
}

.dist-seg-gk {
  width: 13.33%;
  background: #059669;
}

.preset-dist-legend {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 600;
}

.dist-leg-item {
  display: flex;
  align-items: center;
  gap: 5px;
}

.dist-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
}

.dot-cs { background: #2563eb; }
.dot-pedagogy { background: #7c3aed; }
.dot-gk { background: #059669; }

/* Specs Grid */
.preset-specs-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin-bottom: 16px;
}

.preset-spec-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-primary);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-main);
  border: 1px solid var(--border-light);
}

.preset-spec-pill span:first-child {
  font-size: 0.95rem;
}

/* Attempt status */
.preset-history-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
  padding-top: 10px;
  border-top: 1px dashed var(--border-color);
  margin-bottom: 14px;
}

.status-badge-unattempted {
  color: var(--text-dim);
  font-weight: 500;
}

.status-badge-completed {
  color: var(--accent-green);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.btn-start-preset-mock {
  width: 100%;
  padding: 13px 18px;
  min-height: 48px;
  background: linear-gradient(135deg, #2563eb, #3b82f6);
  border: none;
  color: #ffffff;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.btn-start-preset-mock:hover {
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.38);
  transform: translateY(-1px);
}

.btn-start-preset-mock:active {
  transform: translateY(1px);
}

.btn-start-preset-mock .btn-arrow {
  transition: transform 0.2s ease;
}

.btn-start-preset-mock:hover .btn-arrow {
  transform: translateX(4px);
}

/* Custom Builder Card */
.custom-builder-card {
  background: var(--bg-card);
  border: 1px dashed var(--accent-blue);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-bottom: 32px;
}

.builder-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.builder-controls-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

/* ==========================================================================
   6. QUESTION BANK (SUBJECT BROWSER)
   ========================================================================== */
.mobile-unit-select-bar {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  margin-bottom: 20px;
  flex-direction: column;
  gap: 8px;
}

.mobile-unit-select-bar label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-blue);
}

.qbank-layout {
  display: grid;
  grid-template-columns: 290px 1fr;
  gap: 28px;
}

.qbank-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  max-height: calc(100vh - 180px);
  overflow-y: auto;
  position: sticky;
  top: 90px;
}

.unit-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.unit-nav-btn {
  width: 100%;
  text-align: left;
  padding: 10px 14px;
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 0.86rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  transition: var(--transition-fast);
}

.unit-nav-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-main);
}

.unit-nav-btn.active {
  background: var(--accent-blue-bg);
  color: var(--accent-blue);
  font-weight: 700;
}

.unit-nav-count {
  font-size: 0.72rem;
  background: var(--bg-secondary);
  padding: 2px 8px;
  border-radius: 8px;
}

.qbank-main {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.filter-bar {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
}

.search-input-wrap {
  flex: 1;
  min-width: 240px;
  position: relative;
}

#qbankQuestionsList,
#savedItemsContent,
#solutionsReviewContainer {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.question-item-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 26px 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 24px;
}

.question-item-card:last-child {
  margin-bottom: 0;
}

.q-meta-tags {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.q-unit-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-blue);
  background: var(--accent-blue-bg);
  padding: 4px 12px;
  border-radius: 12px;
}

.q-stem-text {
  font-size: 1.08rem;
  font-weight: 600;
  line-height: 1.6;
}

.opts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.opt-btn {
  text-align: left;
  padding: 14px 18px;
  min-height: 50px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: var(--transition-fast);
  width: 100%;
}

.opt-btn:hover {
  border-color: var(--accent-blue);
  background: var(--bg-card-hover);
}

.opt-btn.correct {
  background: var(--accent-green-bg) !important;
  border-color: var(--accent-green) !important;
  color: #047857 !important;
  font-weight: 600;
}

.opt-btn.wrong {
  background: var(--accent-red-bg) !important;
  border-color: var(--accent-red) !important;
  color: #b91c1c !important;
}

.explanation-box {
  background: var(--bg-secondary);
  border-left: 4px solid var(--accent-blue);
  padding: 16px 20px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  display: none;
  margin-top: 6px;
}

.explanation-box.show {
  display: block;
}

/* Dynamic Drill Hero Card */
.drill-hero-card {
  text-align: center;
  padding: 44px 28px;
  max-width: 680px;
  margin: 0 auto;
}

/* ==========================================================================
   7. EXAM SIMULATION MODAL (FULLSCREEN EXAM ROOM)
   ========================================================================== */
.exam-modal {
  position: fixed;
  inset: 0;
  z-index: 3000;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.exam-modal.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.exam-topbar {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 14px 24px;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.exam-title-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: 45%;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.exam-timer {
  background: var(--accent-amber-bg);
  color: var(--accent-amber);
  border: 1px solid rgba(245, 158, 11, 0.4);
  padding: 6px 18px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.exam-timer.danger {
  background: var(--accent-red-bg);
  color: var(--accent-red);
  animation: pulse 1s infinite;
}

.exam-topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn-palette-toggle {
  display: none;
}

.exam-body {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 320px;
  overflow: hidden;
}

.exam-question-area {
  padding: 36px 48px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
}

.exam-nav-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--border-color);
  gap: 14px;
}

.exam-palette-sidebar {
  background: var(--bg-card);
  border-left: 1px solid var(--border-color);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  overflow-y: auto;
}

.palette-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.palette-legend span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.palette-legend b {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: inline-block;
}

.palette-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

.palette-btn {
  aspect-ratio: 1;
  min-height: 42px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-main);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast);
}

.palette-btn.current {
  border: 2px solid var(--accent-blue);
  box-shadow: 0 0 10px var(--accent-blue);
}

.palette-btn.answered {
  background: var(--accent-green);
  color: #fff;
  border-color: var(--accent-green);
}

.palette-btn.review {
  background: var(--accent-amber);
  color: #fff;
  border-color: var(--accent-amber);
}

.palette-btn.ans-review {
  background: var(--accent-purple);
  color: #fff;
  border-color: var(--accent-purple);
}

/* Mobile CBT Palette Drawer */
.exam-palette-drawer-backdrop {
  position: fixed;
  inset: 0;
  z-index: 3100;
  background: rgba(0, 0, 0, 0.6);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease;
}

.exam-palette-drawer-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.exam-palette-drawer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  max-height: 75vh;
  z-index: 3101;
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: 24px;
  overflow-y: auto;
  transform: translateY(100%);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: var(--shadow-lg);
}

.exam-palette-drawer.active {
  transform: translateY(0);
}

.drawer-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
  font-weight: 700;
}

/* ==========================================================================
   8. RESULTS MODAL & SCORECARD
   ========================================================================== */
.results-content-wrap {
  padding: 36px 24px;
  max-width: 880px;
  margin: 0 auto;
  width: 100%;
  overflow-y: auto;
}

.scorecard-banner {
  background: linear-gradient(135deg, var(--accent-blue-bg), var(--accent-purple-bg));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  text-align: center;
  margin-bottom: 28px;
}

.score-big {
  font-size: 3.6rem;
  font-weight: 900;
  font-family: var(--font-display);
  color: var(--accent-blue);
  line-height: 1;
  margin: 14px 0;
}

.pass-badge {
  display: inline-block;
  padding: 6px 22px;
  border-radius: 20px;
  font-size: 0.88rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.pass-badge.pass {
  background: var(--accent-green-bg);
  color: var(--accent-green);
  border: 1px solid var(--accent-green);
}

.pass-badge.fail {
  background: var(--accent-red-bg);
  color: var(--accent-red);
  border: 1px solid var(--accent-red);
}

.results-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  text-align: center;
  margin-bottom: 28px;
}

.stat-result-card {
  padding: 20px 14px;
}

/* ==========================================================================
   9. MEDIA QUERIES FOR RESPONSIVE SPACING (PIXEL-PERFECT MOBILE BREAKPOINTS)
   ========================================================================== */
@media (max-width: 1024px) {
  .qbank-layout {
    grid-template-columns: 250px 1fr;
    gap: 20px;
  }
}

@media (max-width: 900px) {
  .mobile-hamburger-btn {
    display: flex;
  }

  .nav-tabs-bar {
    display: none;
  }

  .mobile-bottom-nav {
    display: flex;
  }

  .stat-chip {
    display: none;
  }

  .user-profile-badge {
    display: none;
  }

  .main-content-wrapper {
    padding: 20px 16px 110px;
  }

  /* Question Bank Layout on Mobile */
  .mobile-unit-select-bar {
    display: flex;
  }

  .qbank-layout {
    grid-template-columns: 1fr;
  }

  .qbank-sidebar {
    display: none;
  }

  /* Exam Modal on Mobile */
  .exam-body {
    grid-template-columns: 1fr;
  }

  .exam-palette-sidebar {
    display: none;
  }

  .btn-palette-toggle {
    display: inline-flex;
  }

  .exam-question-area {
    padding: 20px 16px 95px;
  }

  .exam-nav-controls {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 14px 18px;
    margin-top: 0;
    border-top: 1px solid var(--border-color);
    z-index: 100;
  }
}

@media (max-width: 768px) {
  .hero-readiness-card {
    flex-direction: column-reverse;
    text-align: center;
    padding: 28px 20px;
    gap: 20px;
  }

  .hero-text p {
    margin-left: auto;
    margin-right: auto;
  }

  .quick-actions-row {
    justify-content: center;
  }

  .readiness-ring-wrap {
    margin: 0 auto 8px;
  }

  .opts-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .results-stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .exam-topbar {
    padding: 10px 14px;
  }

  .exam-title-wrap {
    max-width: 35%;
  }

  .btn-submit-exam span {
    font-size: 0.82rem;
  }

  .question-item-card {
    padding: 18px 16px;
  }

  .custom-builder-card {
    padding: 20px 16px;
  }
}

@media (max-width: 480px) {
  .brand-info h1 {
    font-size: 0.98rem;
  }
  .brand-info p {
    font-size: 0.68rem;
  }
  .screen-title {
    font-size: 1.3rem;
  }
  .card {
    padding: 18px 14px;
  }
  .cards-grid-4 {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .mock-cards-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .builder-controls-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
}

/* Keyframes */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}