/* Battery Guide - Main Stylesheet */

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #059669;
    --accent: #dc2626;
    --bg: #f8fafc;
    --bg-white: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.1);
    --radius: 8px;
}

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 40px 0;
    text-align: center;
}

.logo {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.tagline {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation */
.nav {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.nav-list {
    display: flex;
    justify-content: center;
    gap: 8px;
    list-style: none;
    padding: 16px 0;
    flex-wrap: wrap;
}

.nav-list a {
    color: var(--text);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: var(--radius);
    transition: background-color 0.2s, color 0.2s;
    font-weight: 500;
}

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

/* Main Content */
.main {
    padding: 40px 0;
}

.hero {
    text-align: center;
    padding: 40px 0;
    max-width: 700px;
    margin: 0 auto;
}

.hero h2 {
    font-size: 2rem;
    margin-bottom: 16px;
    color: var(--primary);
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* Sections */
.section {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 32px;
    margin-bottom: 32px;
    box-shadow: var(--shadow);
}

.section h2 {
    font-size: 1.75rem;
    margin-bottom: 12px;
    color: var(--text);
    border-bottom: 3px solid var(--primary);
    padding-bottom: 12px;
    display: inline-block;
}

.section > p {
    color: var(--text-light);
    margin-bottom: 24px;
}

/* Tables */
.table-wrapper {
    overflow-x: auto;
    margin: 20px 0;
}

.battery-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.battery-table th,
.battery-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.battery-table th {
    background-color: var(--primary);
    color: white;
    font-weight: 600;
    white-space: nowrap;
}

.battery-table tbody tr:hover {
    background-color: #f1f5f9;
}

.battery-table td strong {
    color: var(--primary);
}

/* Info Box */
.info-box {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-left: 4px solid var(--primary);
    padding: 20px;
    border-radius: 0 var(--radius) var(--radius) 0;
    margin-top: 24px;
}

.info-box h3 {
    color: var(--primary);
    margin-bottom: 8px;
}

/* Card Grid */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.card h3 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1.1rem;
}

.card ul {
    list-style: none;
}

.card li {
    padding: 6px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.95rem;
}

.card li:last-child {
    border-bottom: none;
}

/* Comparison Boxes */
.comparison-box {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
    border-left: 4px solid var(--secondary);
}

.comparison-box h3 {
    color: var(--secondary);
    margin-bottom: 8px;
}

.comparison-box p {
    color: var(--text);
    margin: 0;
}

/* Tips Section */
.tips-section {
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.tip {
    background: var(--bg-white);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.tip h4 {
    color: var(--secondary);
    margin-bottom: 8px;
}

.tip p {
    font-size: 0.95rem;
    color: var(--text-light);
    margin: 0;
}

/* Product Grid (Affiliate) */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.product-card {
    display: block;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.product-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.product-card h3 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1rem;
    line-height: 1.4;
}

.product-card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0;
}

/* Footer */
.footer {
    background: var(--text);
    color: white;
    text-align: center;
    padding: 24px 0;
    margin-top: 40px;
}

.footer p {
    opacity: 0.8;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 30px 0;
    }

    .logo {
        font-size: 2rem;
    }

    .section {
        padding: 20px;
    }

    .section h2 {
        font-size: 1.4rem;
    }

    .battery-table {
        font-size: 0.85rem;
    }

    .battery-table th,
    .battery-table td {
        padding: 8px 12px;
    }

    .hero h2 {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .nav-list {
        gap: 4px;
    }

    .nav-list a {
        padding: 6px 12px;
        font-size: 0.9rem;
    }

    .card-grid {
        grid-template-columns: 1fr;
    }
}