/* style.css - SolveX Main Styles */
:root {
    /* Blue & Navy Color Palette */
    --primary: #2563eb;
    --primary-dark: #1e3a8a;
    --primary-light: #3b82f6;
    --secondary: #0f172a;
    --accent: #06b6d4;
    --background: #ffffff;
    --surface: #f8fafc;
    --text: #0f172a;
    --text-light: #64748b;
    --border: #e2e8f0;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --card-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --primary: #3b82f6;
    --primary-dark: #1d4ed8;
    --background: #0f172a;
    --surface: #1e293b;
    --text: #f1f5f9;
    --text-light: #94a3b8;
    --border: #334155;
    --card-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--background);
    color: var(--text);
    transition: var(--transition);
    line-height: 1.6;
}

/* Header & Navigation */
.header {
    background: linear-gradient(135deg, var(--primary-dark), var(--secondary));
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 2rem;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff, #93c5fd);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-light), var(--accent));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.nav-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.icon-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    color: white;
    transition: var(--transition);
    font-size: 1.25rem;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.05);
}

.language-selector {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    color: white;
    cursor: pointer;
    font-weight: 500;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--secondary) 100%);
    padding: 4rem 2rem;
    text-align: center;
    color: white;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), var(--primary-light));
    border: none;
    padding: 1rem 2rem;
    font-size: 1.125rem;
    font-weight: 600;
    border-radius: 2rem;
    color: white;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* Cards Grid */
.cards-grid {
    max-width: 1400px;
    margin: 3rem auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--surface);
    border-radius: 1.5rem;
    padding: 1.5rem;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    cursor: pointer;
    border: 1px solid var(--border);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-light), var(--accent));
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin-bottom: 1rem;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.card p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.card-btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    cursor: pointer;
    transition: var(--transition);
}

/* Progress Bar */
.progress-container {
    background: var(--border);
    border-radius: 1rem;
    height: 8px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-bar {
    background: linear-gradient(90deg, var(--primary), var(--accent));
    height: 100%;
    width: 0%;
    transition: width 0.3s ease;
}

/* Activity Page Styles */
.activity-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
}

.question-card {
    background: var(--surface);
    border-radius: 2rem;
    padding: 2rem;
    box-shadow: var(--card-shadow);
}

.question-text {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    text-align: center;
}

.options-grid {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

.option {
    background: var(--background);
    border: 2px solid var(--border);
    border-radius: 1rem;
    padding: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.option:hover {
    border-color: var(--primary);
    transform: translateX(5px);
}

.option.correct {
    background: var(--success);
    color: white;
    border-color: var(--success);
}

.option.wrong {
    background: var(--error);
    color: white;
    border-color: var(--error);
}

.number-input {
    width: 100%;
    padding: 1rem;
    font-size: 1.25rem;
    border: 2px solid var(--border);
    border-radius: 1rem;
    background: var(--background);
    color: var(--text);
}

.stars {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    margin: 1rem 0;
}

.star {
    font-size: 2rem;
    color: var(--border);
    cursor: pointer;
}

.star.active {
    color: var(--warning);
}

/* Footer */
.footer {
    background: var(--secondary);
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
        padding: 0 1rem;
    }
    
    .activity-container {
        padding: 1rem;
    }
    
    .question-text {
        font-size: 1.25rem;
    }
}