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

:root {
    --primary: #1a56db;
    --primary-dark: #1e429f;
    --secondary: #0f172a;
    --accent: #f59e0b;
    --text: #334155;
    --text-light: #64748b;
    --bg: #ffffff;
    --bg-gray: #f8fafc;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

/* ========== Header & Navigation ========== */
.header {
    background: #fff;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.5px;
}

.logo span {
    color: var(--secondary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    font-weight: 500;
    color: var(--text);
    transition: color 0.2s;
    position: relative;
}

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

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: -24px;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text);
    border-radius: 2px;
}

/* ========== Hero Section ========== */
.hero {
    background: linear-gradient(135deg, #1e3a8a 0%, #1a56db 50%, #3b82f6 100%);
    color: #fff;
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 700px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    line-height: 1.8;
}

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

.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
}

.btn-primary:hover {
    background: #d97706;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.btn-outline:hover {
    background: #fff;
    color: var(--primary);
}

/* ========== Section Common ========== */
.section {
    padding: 80px 0;
}

.section-gray {
    background: var(--bg-gray);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.2rem;
    color: var(--secondary);
    margin-bottom: 1rem;
}

.section-header p {
    color: var(--text-light);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ========== Product Categories ========== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.product-card {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border: 1px solid var(--border);
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.product-image {
    height: 200px;
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
}

.product-info {
    padding: 1.5rem;
}

.product-info h3 {
    font-size: 1.25rem;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.product-info p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ========== Why Choose Us ========== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.feature-item {
    text-align: center;
    padding: 2rem 1.5rem;
}

.feature-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary) 0%, #3b82f6 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: #fff;
}

.feature-item h3 {
    font-size: 1.15rem;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.feature-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ========== About Preview ========== */
.about-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    font-size: 2rem;
    color: var(--secondary);
    margin-bottom: 1.5rem;
}

.about-text p {
    color: var(--text);
    margin-bottom: 1.25rem;
    line-height: 1.8;
}

.about-image {
    height: 400px;
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
}

/* ========== CTA Section ========== */
.cta-section {
    background: linear-gradient(135deg, var(--secondary) 0%, #1e293b 100%);
    color: #fff;
    text-align: center;
    padding: 80px 0;
}

.cta-section h2 {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.cta-section p {
    font-size: 1.1rem;
    opacity: 0.8;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ========== Footer ========== */
.footer {
    background: var(--secondary);
    color: #94a3b8;
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.footer-col ul {
    list-style: none;
}

.footer-col li {
    margin-bottom: 0.75rem;
}

.footer-col a {
    color: #94a3b8;
    transition: color 0.2s;
}

.footer-col a:hover {
    color: #fff;
}

.footer-brand p {
    margin-bottom: 1rem;
    line-height: 1.7;
}

.footer-brand .logo {
    color: #fff;
    margin-bottom: 1rem;
    display: block;
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 2rem;
    text-align: center;
    font-size: 0.9rem;
}

/* ========== Page Header ========== */
.page-header {
    background: linear-gradient(135deg, #1e3a8a 0%, #1a56db 100%);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    opacity: 0.9;
    font-size: 1.1rem;
}

.breadcrumb {
    margin-top: 1rem;
    font-size: 0.9rem;
    opacity: 0.8;
}

.breadcrumb a {
    color: #fff;
}

/* ========== Products Detail Page ========== */
.product-category-section {
    padding: 60px 0;
}

.product-category-section:nth-child(even) {
    background: var(--bg-gray);
}

.category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.category-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary) 0%, #3b82f6 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: #fff;
    flex-shrink: 0;
}

.category-header h2 {
    font-size: 1.8rem;
    color: var(--secondary);
}

.product-items-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.product-item {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.product-item:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.product-item-img {
    height: 160px;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
}

.product-item-info {
    padding: 1rem;
}

.product-item-info h4 {
    font-size: 0.95rem;
    color: var(--secondary);
    margin-bottom: 0.25rem;
}

.product-item-info p {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* ========== Contact Page ========== */
.contact-wrap {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 4rem;
}

.contact-info h3 {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    align-items: flex-start;
}

.contact-item-icon {
    width: 45px;
    height: 45px;
    background: #eff6ff;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.contact-item-text h4 {
    font-size: 1rem;
    color: var(--secondary);
    margin-bottom: 0.25rem;
}

.contact-item-text p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.contact-form {
    background: #fff;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.contact-form h3 {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 1.5rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--secondary);
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .product-items-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    .mobile-toggle {
        display: flex;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .hero {
        padding: 60px 0;
    }
    .section {
        padding: 50px 0;
    }
    .section-header h2 {
        font-size: 1.7rem;
    }
    .about-wrap {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .contact-wrap {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .product-items-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .form-row {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .hero-buttons {
        flex-direction: column;
    }
    .btn {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .products-grid {
        grid-template-columns: 1fr;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .product-items-grid {
        grid-template-columns: 1fr;
    }
}