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

:root {
    --bg-color: #020617;
    --card-bg: rgba(30, 41, 59, 0.7);
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --success: #10b981;
    --error: #ef4444;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --glass-border: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    background-image: 
        radial-gradient(circle at 20% 20%, rgba(59, 130, 246, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 80% 80%, rgba(16, 185, 129, 0.1) 0%, transparent 40%);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
}

h1, h2, h3 {
    font-family: 'Outfit', sans-serif;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInDown 0.8s ease-out;
}

.logo {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #60a5fa, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Dashboard */
.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 2rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.card:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.card i {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.5rem;
}

.card p {
    color: var(--text-muted);
    line-height: 1.6;
}

/* Quiz UI */
#app-content {
    min-height: 60vh;
}

.quiz-container {
    animation: fadeIn 0.5s ease-out;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
    margin-bottom: 2rem;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary);
    width: 0%;
    transition: width 0.4s ease;
}

.question-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 2.5rem;
    margin-bottom: 2rem;
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
}

.question-text {
    font-size: 1.3rem;
    line-height: 1.6;
    margin-bottom: 2rem;
    font-weight: 500;
}

.options-grid {
    display: grid;
    gap: 1rem;
}

.option {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 1.25rem 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 1rem;
    text-align: left;
    font-size: 1rem;
}

.option:hover:not(.disabled) {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
}

.option.selected {
    border-color: var(--primary);
    background: rgba(59, 130, 246, 0.1);
}

.option.correct {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.15);
    color: #4ade80;
}

.option.wrong {
    border-color: var(--error);
    background: rgba(239, 68, 68, 0.15);
    color: #f87171;
}

.option-letter {
    width: 32px;
    height: 32px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.option.selected .option-letter {
    background: var(--primary);
}

.option.correct .option-letter {
    background: var(--success);
}

.option.wrong .option-letter {
    background: var(--error);
}

/* Explanation */
.explanation {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(16, 185, 129, 0.05);
    border-left: 4px solid var(--success);
    border-radius: 0.5rem;
    display: none;
    animation: slideDown 0.4s ease-out;
}

.explanation h4 {
    color: var(--success);
    margin-bottom: 0.5rem;
}

.explanation p {
    line-height: 1.6;
    color: #cbd5e1;
}

/* Controls */
.quiz-controls {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}

.btn {
    padding: 0.8rem 2rem;
    border-radius: 1rem;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: scale(1.05);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Syllabus View */
.syllabus-container {
    animation: fadeIn 0.5s ease-out;
}

.chapter-card {
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.chapter-card h3 {
    color: var(--primary);
    margin-bottom: 1rem;
}

.chapter-card ul {
    list-style: none;
}

.chapter-card li {
    margin-bottom: 0.75rem;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.6;
}

.chapter-card li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--success);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 600px) {
    .container { padding: 1rem; }
    .logo { font-size: 2rem; }
    .question-card { padding: 1.5rem; }
}