/* ========================================
   Bank Soal AI - Modern Responsive Styles
   ======================================== */

:root {
    /* Color Palette */
    --primary-color: #4f46e5;
    --primary-dark: #4338ca;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --gray-color: #6b7280;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-ai: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-base: all 0.3s ease;
}

/* ========================================
   Global Styles
   ======================================== */

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(to bottom right, #f9fafb, #e5e7eb);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

/* ========================================
   Navigation
   ======================================== */

.navbar {
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
}

.bg-gradient-primary {
    background: var(--gradient-primary) !important;
}

.navbar-brand {
    font-size: 1.5rem;
    letter-spacing: -0.5px;
}

.nav-link {
    transition: var(--transition-base);
    border-radius: 0.5rem;
    margin: 0 0.25rem;
    padding: 0.5rem 1rem !important;
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.nav-link.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 600;
}

/* ========================================
   Cards
   ======================================== */

.card {
    border: none;
    border-radius: 1rem;
    transition: var(--transition-base);
    overflow: hidden;
}

.hover-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl) !important;
}

.card-header {
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    padding: 1.25rem 1.5rem;
}

.card-body {
    padding: 1.5rem;
}

/* ========================================
   Statistics Cards
   ======================================== */

.stat-card {
    background: white;
    border-radius: 1rem;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
}

.stat-card-primary .stat-icon {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.stat-card-success .stat-icon {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.stat-card-warning .stat-icon {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
}

.stat-card-info .stat-icon {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: white;
}

.stat-content h3 {
    font-size: 2rem;
    font-weight: bold;
    margin: 0;
    color: var(--dark-color);
}

.stat-content p {
    margin: 0;
    color: var(--gray-color);
    font-size: 0.875rem;
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    border-radius: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-weight: 500;
    transition: var(--transition-base);
    border: none;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-gradient-ai {
    background: var(--gradient-ai);
    color: white;
    border: none;
}

.btn-gradient-ai:hover {
    background: linear-gradient(135deg, #f5576c 0%, #f093fb 100%);
    color: white;
}

.btn-ai-generate {
    position: relative;
    overflow: hidden;
}

.btn-ai-generate::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-ai-generate:hover::before {
    width: 300px;
    height: 300px;
}

/* ========================================
   AI Card
   ======================================== */

.ai-card {
    background: white;
    position: relative;
    overflow: hidden;
}

.ai-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: var(--gradient-ai);
}

.bg-gradient-ai {
    background: var(--gradient-ai) !important;
}

/* ========================================
   Question Options
   ======================================== */

.option-box {
    padding: 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 0.75rem;
    transition: var(--transition-base);
    background: white;
}

.option-box:hover {
    border-color: var(--primary-color);
    background: rgba(79, 70, 229, 0.05);
}

.option-correct {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.1);
    font-weight: 500;
}

/* ========================================
   Forms
   ======================================== */

.form-control,
.form-select {
    border-radius: 0.5rem;
    border: 1px solid #d1d5db;
    padding: 0.625rem 1rem;
    transition: var(--transition-base);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

/* ========================================
   Badges
   ======================================== */

.badge {
    padding: 0.375rem 0.75rem;
    border-radius: 0.5rem;
    font-weight: 500;
}

/* ========================================
   Alerts
   ======================================== */

.alert {
    border-radius: 0.75rem;
    border: none;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background: white;
    box-shadow: 0 -4px 6px -1px rgba(0, 0, 0, 0.1);
    margin-top: 4rem;
}

/* ========================================
   Loading State
   ======================================== */

.spinner-border {
    animation: spinner-border 0.75s linear infinite;
}

@keyframes spinner-border {
    to {
        transform: rotate(360deg);
    }
}

/* ========================================
   Animations
   ======================================== */

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

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

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
    .stat-card {
        flex-direction: column;
        text-align: center;
    }
    
    .stat-icon {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }
    
    .stat-content h3 {
        font-size: 1.5rem;
    }
    
    .navbar-brand {
        font-size: 1.25rem;
    }
}

@media (max-width: 576px) {
    .card-body {
        padding: 1rem;
    }
    
    .btn {
        font-size: 0.875rem;
    }
}

/* ========================================
   Utilities
   ======================================== */

.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.shadow-glass {
    background: rgba(255, 255, 255, 0.25);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.18);
}