/* Base & Tokens */
:root {
  --bg-color: #0f172a;
  --panel-bg: rgba(30, 41, 59, 0.7);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --secondary: #64748b;
  --secondary-hover: #475569;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --info: #0ea5e9;
  
  --palette-answered: #10b981;
  --palette-marked-answered: #3b82f6;
  --palette-marked-unanswered: #f59e0b;
  --palette-unanswered: #f8fafc;

  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --radius: 12px;
  --radius-sm: 8px;
  
  --transition: all 0.3s ease;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg-color);
  background-image: 
    radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
    radial-gradient(circle at 85% 30%, rgba(16, 185, 129, 0.15), transparent 25%);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3 {
  font-weight: 700;
  margin-bottom: 1rem;
}
p {
  line-height: 1.6;
}

/* Utilities */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.hidden { display: none !important; }
.full-width { width: 100%; }

/* Buttons */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  color: white;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}
.btn:active {
  transform: translateY(0);
}
.primary { background: var(--primary); }
.primary:hover { background: var(--primary-hover); }
.secondary { background: var(--secondary); }
.secondary:hover { background: var(--secondary-hover); }
.success { background: var(--success); }
.warning { background: var(--warning); color: #fff; }
.danger { background: var(--danger); }
.danger:hover { background: var(--danger-hover); }

/* Glass Panel */
.glass-panel {
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  padding: 2rem;
}

/* Home Layout */
.container {
  max-width: 800px;
  margin: auto;
  padding: 2rem;
  width: 100%;
}
.selection-container {
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 2rem;
  margin-top: 2rem;
  animation: fadeIn 0.5s ease-out;
}
.button-group {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}
.test-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1rem;
}
.test-card {
  padding: 1.5rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}
.test-card:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Test Interface Layout */
.test-body {
  height: 100vh;
  overflow: hidden;
}
.test-header {
  height: 70px;
  background: var(--panel-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}
.test-header h1 {
  margin: 0;
  font-size: 1.5rem;
  background: linear-gradient(90deg, #3b82f6, #10b981);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.timer-container {
  font-size: 1.25rem;
  font-weight: bold;
  color: var(--success);
  background: rgba(16, 185, 129, 0.1);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.test-container {
  display: flex;
  height: calc(100vh - 70px);
}

.question-main {
  flex: 1;
  padding: 2rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--glass-border);
}
.question-header h2 {
  margin: 0;
  color: var(--info);
}
.subject-badge {
  background: rgba(59, 130, 246, 0.2);
  color: #60a5fa;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.question-content {
  font-size: 1.25rem;
  line-height: 1.6;
  margin-bottom: 2rem;
  min-height: 100px;
}

.options-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
}

.option-label {
  display: flex;
  align-items: center;
  padding: 1rem 1.5rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}
.option-label:hover {
  background: rgba(255, 255, 255, 0.08);
}
.option-label input[type="radio"] {
  margin-right: 1rem;
  transform: scale(1.2);
  cursor: pointer;
}
.option-label.selected {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--primary);
  box-shadow: 0 0 10px rgba(59, 130, 246, 0.3);
}

.action-buttons {
  display: flex;
  gap: 1rem;
  margin-top: auto;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--glass-border);
}

.submit-container {
  margin-top: 1rem;
}

/* Sidebar Palette */
.palette-sidebar {
  width: 320px;
  background: var(--panel-bg);
  backdrop-filter: blur(10px);
  border-left: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
}
.palette-sidebar h3 {
  padding: 1.5rem;
  margin: 0;
  border-bottom: 1px solid var(--glass-border);
}
.legend {
  padding: 1rem 1.5rem;
  font-size: 0.875rem;
  border-bottom: 1px solid var(--glass-border);
  display: grid;
  gap: 0.5rem;
}
.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.legend-box {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  border: 1px solid rgba(0,0,0,0.2);
}
.legend-box.answered { background: var(--palette-answered); }
.legend-box.marked-answered { background: var(--palette-marked-answered); }
.legend-box.marked-unanswered { background: var(--palette-marked-unanswered); }
.legend-box.unanswered { background: var(--palette-unanswered); }

.palette-grid {
  padding: 1.5rem;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  overflow-y: auto;
}
.palette-btn {
  aspect-ratio: 1;
  border-radius: 4px;
  border: 1px solid rgba(0,0,0,0.3);
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s;
  color: #1a1a1a;
}
.palette-btn:hover {
  transform: scale(1.1);
}

/* Colors for palette buttons */
.pb-default { background: var(--palette-unanswered); }
.pb-answered { background: var(--palette-answered); color: #fff;}
.pb-marked-answered { background: var(--palette-marked-answered); color: #fff;}
.pb-marked-unanswered { background: var(--palette-marked-unanswered); color: #fff;}
.pb-active { border: 2px solid white; box-shadow: 0 0 8px white; transform: scale(1.1); z-index: 10; }

/* Modals */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 1;
  transition: opacity 0.3s;
}
.modal.hidden {
  opacity: 0;
  pointer-events: none;
}
.modal-content {
  background: var(--bg-color);
  padding: 2rem;
  border-radius: var(--radius);
  border: 1px solid var(--glass-border);
  text-align: center;
  max-width: 400px;
  width: 90%;
}
.modal-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 1.5rem;
}

/* Results Page */
.result-body {
  justify-content: center;
  align-items: center;
}
.result-container {
  width: 100%;
  max-width: 600px;
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 2rem;
  animation: fadeIn 0.5s ease-out;
}
.score-card {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 2rem;
  border-radius: var(--radius);
  margin: 1.5rem 0;
}
.score {
  font-size: 3rem;
  font-weight: 800;
  color: var(--success);
  margin: 1rem 0;
}
.subject-scores {
  display: grid;
  gap: 1rem;
}
.subject-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  padding: 1rem;
  border-radius: var(--radius-sm);
  text-align: left;
}

/* Scrollbar styling */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: rgba(0,0,0,0.1); }
::-webkit-scrollbar-thumb { background: var(--secondary); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--secondary-hover); }

/* Responsive tweaks */
@media (max-width: 768px) {
  .test-container {
    flex-direction: column;
    height: auto;
  }
  .test-body {
    overflow: auto;
  }
  .palette-sidebar {
    width: 100%;
    height: auto;
    max-height: 400px;
    border-left: none;
    border-top: 1px solid var(--glass-border);
  }
  .action-buttons {
    flex-direction: column;
  }
  .btn { width: 100%; justify-content: center; }
}