/* ==========================================================================
   SSC CGL AIR 1 REVISION PORTAL - OPERATION SELECTION 🎯
   Clean Google Light Theme with Inter Font & Strict 2px Corner Radius
   ========================================================================== */

:root {
  /* Google Light Palette System */
  --g-bg-base: #f8f9fa;
  --g-surface-1: #ffffff;
  --g-surface-2: #f1f3f4;
  --g-surface-3: #e8eaed;
  
  --g-border: #dadce0;
  --g-border-subtle: #e8eaed;

  --g-text-primary: #202124;
  --g-text-secondary: #5f6368;
  --g-text-muted: #70757a;

  /* Google Light Accent Palette */
  --g-blue: #1a73e8;
  --g-blue-dark: #1557b0;
  --g-blue-bg: #e8f0fe;
  --g-blue-border: #aecbfa;

  --g-green: #137333;
  --g-green-bg: #e6f4ea;
  --g-green-border: #a8dab5;

  --g-yellow: #b06000;
  --g-yellow-bg: #fef7e0;
  --g-yellow-border: #fde293;
  --g-yellow-solid: #f9ab00;

  --g-red: #c5221f;
  --g-red-bg: #fce8e6;
  --g-red-border: #fad2cf;

  --g-purple: #6b21a8;
  --g-purple-bg: #f3e8ff;
  --g-purple-border: #d8b4fe;

  /* Typography */
  --font-inter: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', Consolas, monospace;

  /* STRICT 2PX CORNER RADIUS EVERYWHERE */
  --radius-xs: 2px;
  --radius-sm: 2px;
  --radius-md: 2px;
  --radius-lg: 2px;
  --radius-xl: 2px;
  --radius-pill: 2px;

  /* Subtle Clean Shadows */
  --g-shadow-1: 0 1px 2px 0 rgba(60, 64, 67, 0.1), 0 1px 3px 1px rgba(60, 64, 67, 0.05);
  --g-shadow-2: 0 1px 3px 0 rgba(60, 64, 67, 0.15), 0 4px 8px 3px rgba(60, 64, 67, 0.1);
  --g-shadow-3: 0 4px 12px 0 rgba(60, 64, 67, 0.2);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--g-bg-base);
  color: var(--g-text-primary);
  font-family: var(--font-inter);
  line-height: 1.6;
  min-height: 100vh;
  padding-bottom: 60px;
}

/* App Container */
.app-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header - Clean Google Workspace Style (Light) */
.top-header {
  background: var(--g-surface-1);
  border-bottom: 1px solid var(--g-border);
  padding: 16px 0;
  margin-bottom: 24px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.header-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

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

.brand-badge {
  background: #f9ab00;
  color: #202124;
  font-weight: 700;
  font-size: 0.75rem;
  padding: 4px 10px;
  border-radius: 2px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.brand-title h1 {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--g-text-primary);
  letter-spacing: -0.3px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.target-pills {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.target-pill {
  background: var(--g-surface-2);
  border: 1px solid var(--g-border);
  padding: 6px 14px;
  border-radius: 2px;
  font-size: 0.85rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--g-text-secondary);
}

.target-pill strong {
  color: var(--g-text-primary);
  font-weight: 700;
}

.target-pill.math strong { color: var(--g-blue); }
.target-pill.gs strong { color: var(--g-green); }

/* Dashboard Summary Cards - Google System Light */
.dashboard-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: var(--g-shadow-1);
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.stat-card:hover {
  border-color: var(--g-blue);
  transform: translateY(-1px);
}

.stat-icon {
  width: 44px;
  height: 44px;
  border-radius: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.stat-icon.gold { color: var(--g-yellow); background: var(--g-yellow-bg); border: 1px solid var(--g-yellow-border); }
.stat-icon.blue { color: var(--g-blue); background: var(--g-blue-bg); border: 1px solid var(--g-blue-border); }
.stat-icon.emerald { color: var(--g-green); background: var(--g-green-bg); border: 1px solid var(--g-green-border); }
.stat-icon.purple { color: var(--g-purple); background: var(--g-purple-bg); border: 1px solid var(--g-purple-border); }

.stat-info .val {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--g-text-primary);
  line-height: 1.2;
}

.stat-info .lbl {
  font-size: 0.78rem;
  color: var(--g-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
  margin-top: 2px;
}

/* Navigation & Controls Wrapper */
.controls-wrapper {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 16px 20px;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  box-shadow: var(--g-shadow-1);
}

@media (min-width: 900px) {
  .controls-wrapper {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.day-selector {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.day-badge {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  color: var(--g-text-secondary);
  padding: 8px 16px;
  border-radius: 2px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.day-badge.active {
  background: var(--g-blue);
  color: #ffffff;
  border-color: var(--g-blue);
  font-weight: 600;
}

.day-badge.disabled {
  opacity: 0.4;
  cursor: not-allowed;
  background: var(--g-surface-2);
}

/* Subject Chips (2px Corner Radius) */
.subject-filters {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  color: var(--g-text-secondary);
  padding: 8px 16px;
  border-radius: 2px;
  font-size: 0.85rem;
  font-weight: 500;
  font-family: var(--font-inter);
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.filter-btn:hover {
  background: var(--g-surface-2);
  color: var(--g-text-primary);
}

.filter-btn.active {
  background: var(--g-blue-bg);
  color: var(--g-blue-dark);
  border-color: var(--g-blue);
  font-weight: 600;
}

.filter-btn[data-subject="math"].active {
  background: var(--g-blue-bg);
  color: var(--g-blue-dark);
  border-color: var(--g-blue);
}

.filter-btn[data-subject="gs"].active {
  background: var(--g-green-bg);
  color: var(--g-green);
  border-color: var(--g-green);
}

.filter-btn[data-subject="english"].active {
  background: var(--g-purple-bg);
  color: var(--g-purple);
  border-color: var(--g-purple);
}

.filter-btn[data-subject="traps"].active {
  background: var(--g-red-bg);
  color: var(--g-red);
  border-color: var(--g-red);
}

/* Google Light Search Bar */
.search-box {
  position: relative;
  min-width: 240px;
}

.search-input {
  width: 100%;
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 9px 16px 9px 38px;
  color: var(--g-text-primary);
  font-family: var(--font-inter);
  font-size: 0.88rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input:focus {
  border-color: var(--g-blue);
  box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.15);
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--g-text-muted);
  font-size: 0.88rem;
}

/* Main Content Grid */
.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

/* Topic Module Card - Clean White Surface */
.topic-module {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 28px;
  box-shadow: var(--g-shadow-1);
  transition: border-color 0.2s ease;
}

.topic-module:hover {
  border-color: #b0b5ba;
}

.module-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--g-border-subtle);
}

.module-title-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.subject-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 2px;
  letter-spacing: 0.5px;
}

.subject-tag.math { background: var(--g-blue-bg); color: var(--g-blue-dark); border: 1px solid var(--g-blue-border); }
.subject-tag.gs { background: var(--g-green-bg); color: var(--g-green); border: 1px solid var(--g-green-border); }
.subject-tag.english { background: var(--g-purple-bg); color: var(--g-purple); border: 1px solid var(--g-purple-border); }

.module-title-group h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--g-text-primary);
  letter-spacing: -0.2px;
}

.module-actions {
  display: flex;
  gap: 8px;
}

.btn-bookmark, .btn-complete {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  color: var(--g-text-secondary);
  padding: 6px 14px;
  border-radius: 2px;
  font-size: 0.82rem;
  font-weight: 500;
  font-family: var(--font-inter);
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-bookmark:hover, .btn-complete:hover {
  background: var(--g-surface-2);
  color: var(--g-text-primary);
}

.btn-complete.completed {
  background: var(--g-green-bg);
  border-color: var(--g-green);
  color: var(--g-green);
  font-weight: 600;
}

/* Callout Box: TCS Traps (Clean Light Red) */
.trap-box {
  background: var(--g-red-bg);
  border-left: 4px solid var(--g-red);
  border-top: 1px solid var(--g-red-border);
  border-right: 1px solid var(--g-red-border);
  border-bottom: 1px solid var(--g-red-border);
  border-radius: 2px;
  padding: 18px 20px;
  margin: 20px 0;
}

.trap-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--g-red);
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.trap-content {
  color: #5c0f0d;
  font-size: 0.9rem;
  line-height: 1.55;
}

.trap-content ul {
  margin-left: 20px;
  margin-top: 6px;
}

.trap-content li {
  margin-bottom: 6px;
}

/* High-Yield Tip Box (Clean Light Green) */
.tip-box {
  background: var(--g-green-bg);
  border-left: 4px solid var(--g-green);
  border-top: 1px solid var(--g-green-border);
  border-right: 1px solid var(--g-green-border);
  border-bottom: 1px solid var(--g-green-border);
  border-radius: 2px;
  padding: 18px 20px;
  margin: 20px 0;
}

.tip-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--g-green);
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.tip-content {
  color: #0d401c;
  font-size: 0.9rem;
  line-height: 1.55;
}

.tip-content ul {
  margin-left: 20px;
  margin-top: 6px;
}

.tip-content li {
  margin-bottom: 4px;
}

/* Formula & Quick Reference Grid */
.formula-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.formula-card {
  background: var(--g-bg-base);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 16px 20px;
}

.formula-card .title {
  font-size: 0.8rem;
  text-transform: uppercase;
  color: var(--g-yellow);
  font-weight: 700;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.formula-card .math-expr {
  font-family: var(--font-mono);
  font-size: 0.98rem;
  color: var(--g-blue-dark);
  background: var(--g-blue-bg);
  border: 1px solid var(--g-blue-border);
  padding: 6px 10px;
  border-radius: 2px;
  display: inline-block;
  margin-bottom: 8px;
  font-weight: 600;
}

.formula-card .desc {
  font-size: 0.85rem;
  color: var(--g-text-secondary);
  line-height: 1.45;
}

/* KaTeX Formatting Enhancements */
.katex {
  font-size: 1.05em;
  color: #1557b0;
}

.math-expr .katex {
  font-size: 1.08em;
  color: #1557b0;
  font-weight: 600;
}

.ssc-table .katex {
  font-size: 1.02em;
  color: #1967d2;
}

/* Clean Google Table Design (Light) */
.table-wrapper {
  overflow-x: auto;
  margin: 20px 0;
  border-radius: 2px;
  border: 1px solid var(--g-border);
  background: var(--g-surface-1);
}

.ssc-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.88rem;
}

.ssc-table th {
  background: var(--g-surface-2);
  color: var(--g-text-primary);
  font-weight: 700;
  padding: 14px 18px;
  border-bottom: 1px solid var(--g-border);
  white-space: nowrap;
}

.ssc-table td {
  padding: 12px 18px;
  border-bottom: 1px solid var(--g-border-subtle);
  color: var(--g-text-secondary);
}

.ssc-table tr:hover td {
  background: #f8f9fa;
  color: var(--g-text-primary);
}

.highlight-val {
  color: var(--g-blue-dark);
  font-weight: 600;
}

.trap-val {
  color: var(--g-red);
  font-weight: 600;
}

/* Diagrams Box (Light Mode) */
.diagram-box {
  background: #ffffff;
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 24px;
  margin: 24px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.diagram-box svg {
  max-width: 100%;
  height: auto;
}

.diagram-caption {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--g-text-muted);
  text-align: center;
  font-style: italic;
}

/* Sectional Quiz & Practice Questions */
.quiz-section {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 32px;
  margin-top: 36px;
  box-shadow: var(--g-shadow-2);
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--g-border);
}

.quiz-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--g-blue-dark);
}

.q-card {
  background: var(--g-bg-base);
  border: 1px solid var(--g-border);
  border-radius: 2px;
  padding: 22px;
  margin-bottom: 20px;
}

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

.q-num {
  background: var(--g-blue);
  color: #fff;
  font-weight: 700;
  font-size: 0.75rem;
  padding: 4px 8px;
  border-radius: 2px;
}

.q-text {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--g-text-primary);
  line-height: 1.5;
  flex: 1;
}

.options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 10px;
  margin-top: 16px;
}

.option-btn {
  background: var(--g-surface-1);
  border: 1px solid var(--g-border);
  color: var(--g-text-secondary);
  padding: 12px 16px;
  border-radius: 2px;
  font-size: 0.88rem;
  font-family: var(--font-inter);
  text-align: left;
  cursor: pointer;
  transition: all 0.2s ease;
}

.option-btn:hover {
  background: var(--g-surface-2);
  color: var(--g-text-primary);
  border-color: var(--g-blue);
}

.option-btn.selected {
  border-color: var(--g-blue);
  background: var(--g-blue-bg);
  color: var(--g-blue-dark);
}

.option-btn.correct {
  border-color: var(--g-green) !important;
  background: var(--g-green-bg) !important;
  color: var(--g-green) !important;
  font-weight: 700;
}

.option-btn.wrong {
  border-color: var(--g-red) !important;
  background: var(--g-red-bg) !important;
  color: var(--g-red) !important;
}

.q-explanation {
  display: none;
  margin-top: 16px;
  padding: 16px 20px;
  background: var(--g-surface-1);
  border: 1px solid var(--g-blue-border);
  border-radius: 2px;
  font-size: 0.88rem;
  color: var(--g-text-secondary);
  line-height: 1.55;
}

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

.q-explanation strong {
  color: var(--g-blue-dark);
}

/* Floating Navigation Action Button */
.floating-actions {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  gap: 12px;
  z-index: 100;
}

.fab-btn {
  background: var(--g-blue);
  color: #ffffff;
  border: none;
  width: 48px;
  height: 48px;
  border-radius: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--g-shadow-2);
  cursor: pointer;
  transition: transform 0.2s ease, background-color 0.2s ease;
}

.fab-btn:hover {
  transform: translateY(-2px);
  background: var(--g-blue-dark);
}

/* Typography & Utility Helpers */
.text-gold { color: var(--g-yellow); }
.text-cyan { color: var(--g-blue); }
.text-emerald { color: var(--g-green); }
.text-rose { color: var(--g-red); }
.text-purple { color: var(--g-purple); }
.font-bold { font-weight: 700; }
.mb-10 { margin-bottom: 10px; }
.mb-20 { margin-bottom: 20px; }
.mt-10 { margin-top: 10px; }
.mt-20 { margin-top: 20px; }

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

.animate-fade-in {
  animation: fadeIn 0.25s ease-out forwards;
}