:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #0f172a;
    --light: #f8fafc;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --radius: 12px;
    --radius-sm: 8px;
}

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

body {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--light);
    color: var(--dark);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-dark);
}

/* Header */
.header {
    background: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav a {
    font-weight: 500;
    color: var(--secondary);
}

.nav a:hover {
    color: var(--primary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.25rem;
    font-size: 0.95rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

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

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

.btn-sm {
    padding: 0.4rem 0.9rem;
    font-size: 0.85rem;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: box-shadow 0.2s;
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-body {
    padding: 1.5rem;
}

/* Alerts */
.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
}

.alert-warning {
    background: #fef3c7;
    color: #92400e;
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Landing Hero */
.hero {
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #3b82f6 100%);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
}

.hero h1 {
    font-size: 2.75rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.95;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero .btn {
    padding: 0.9rem 1.75rem;
    font-size: 1.05rem;
}

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

.hero .btn-primary:hover {
    background: var(--light);
}

.hero .btn-secondary {
    border-color: white;
    color: white;
}

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

/* Category Grid */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    padding: 3rem 0;
}

.category-card {
    background: white;
    border-radius: var(--radius);
    padding: 1.75rem;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border: 2px solid transparent;
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.category-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.category-card .count {
    font-size: 0.9rem;
    color: var(--secondary);
    margin-bottom: 1rem;
}

/* Auth Pages */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.auth-card {
    width: 100%;
    max-width: 420px;
    padding: 2.5rem;
}

.auth-card h1 {
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
}

/* Admin Sidebar */
.admin-wrapper {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: 260px;
    background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
    color: white;
    padding: 1.5rem 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.admin-sidebar .logo {
    padding: 0 1.5rem 1.5rem;
    font-size: 1.35rem;
    color: white;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 1rem;
}

.admin-sidebar nav a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1.5rem;
    color: rgba(255,255,255,0.8);
    transition: all 0.2s;
}

.admin-sidebar nav a:hover,
.admin-sidebar nav a.active {
    background: rgba(255,255,255,0.1);
    color: white;
}

.admin-main {
    flex: 1;
    margin-left: 260px;
    padding: 1.5rem 2rem;
    background: #f1f5f9;
}

.admin-header {
    background: white;
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-header h2 {
    font-size: 1.35rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.stat-card h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-card p {
    color: var(--secondary);
    font-size: 0.9rem;
    margin-top: 0.25rem;
}

/* Tables */
.table-wrap {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 1rem 1.25rem;
    text-align: left;
}

.table th {
    background: #f8fafc;
    font-weight: 600;
    color: var(--dark);
}

.table tr:hover {
    background: #f8fafc;
}

.table .actions {
    display: flex;
    gap: 0.5rem;
}

/* Quiz Attempt */
.quiz-container {
    max-width: 800px;
    margin: 2rem auto;
}

.question-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.question-card h3 {
    margin-bottom: 1.5rem;
    font-size: 1.15rem;
}

.option-list {
    list-style: none;
}

.option-item {
    padding: 1rem 1.25rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
}

.option-item:hover {
    border-color: var(--primary);
}

.option-item.selected {
    border-color: var(--primary);
    background: #eff6ff;
}

.option-item.correct {
    border-color: var(--success);
    background: #d1fae5;
}

.option-item.wrong {
    border-color: var(--danger);
    background: #fee2e2;
}

/* Result */
.result-summary {
    text-align: center;
    padding: 3rem 2rem;
}

.result-summary .score {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary);
}

.result-summary .passed {
    color: var(--success);
}

.result-summary .failed {
    color: var(--danger);
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--secondary);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .admin-sidebar {
        width: 100%;
        position: relative;
    }
    
    .admin-main {
        margin-left: 0;
    }
    
    .admin-wrapper {
        flex-direction: column;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
}