/* Iron Fitness - 工业力量风格 */
:root {
    --metal-gray: #78909C;
    --power-red: #D32F2F;
    --pure-black: #000000;
    --dark-bg: #1a1a1a;
    --light-gray: #f5f5f5;
    --text-color: #333333;
    --white: #ffffff;
    --border-color: #e0e0e0;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.8;
    background: var(--white);
}

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

/* Header & Navigation */
.site-header {
    background: var(--pure-black);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    gap: 10px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--power-red);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    color: var(--white);
    font-size: 18px;
}

.logo-text {
    color: var(--white);
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo-text span {
    color: var(--power-red);
}

.main-nav {
    display: flex;
    list-style: none;
    gap: 0;
}

.main-nav li a {
    color: #ccc;
    text-decoration: none;
    padding: 10px 16px;
    font-size: 14px;
    transition: all 0.3s;
    display: block;
}

.main-nav li a:hover,
.main-nav li a.active {
    color: var(--white);
    background: var(--power-red);
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 24px;
    cursor: pointer;
}

/* Hero Section */
.hero {
    position: relative;
    height: 600px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--dark-bg);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--white);
    padding: 20px;
}

.hero-content h1 {
    font-size: 48px;
    font-weight: 900;
    margin-bottom: 20px;
    text-shadow: 2px 2px 8px rgba(0,0,0,0.6);
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.9;
}

.btn-primary {
    display: inline-block;
    background: var(--power-red);
    color: var(--white);
    padding: 14px 36px;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    border-radius: 4px;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: #b71c1c;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(211,47,47,0.4);
}

.btn-outline {
    display: inline-block;
    border: 2px solid var(--white);
    color: var(--white);
    padding: 12px 34px;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    border-radius: 4px;
    transition: all 0.3s;
    margin-left: 15px;
}

.btn-outline:hover {
    background: var(--white);
    color: var(--pure-black);
}

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

.section-dark {
    background: var(--dark-bg);
    color: var(--white);
}

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

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title h2 {
    font-size: 36px;
    font-weight: 800;
    color: var(--pure-black);
    margin-bottom: 15px;
}

.section-dark .section-title h2 {
    color: var(--white);
}

.section-title p {
    font-size: 16px;
    color: var(--metal-gray);
    max-width: 600px;
    margin: 0 auto;
}

.section-title .red-line {
    width: 60px;
    height: 4px;
    background: var(--power-red);
    margin: 15px auto 0;
}

/* Product Grid */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.product-card {
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.product-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

.product-card .card-body {
    padding: 20px;
}

.product-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--pure-black);
}

.product-card p {
    font-size: 14px;
    color: #666;
    line-height: 1.6;
}

.product-card .card-link {
    display: inline-block;
    margin-top: 15px;
    color: var(--power-red);
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
}

.product-card .card-link:hover {
    text-decoration: underline;
}

/* Stats Section */
.stats-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    text-align: center;
}

.stat-item .stat-number {
    font-size: 48px;
    font-weight: 900;
    color: var(--power-red);
    display: block;
}

.stat-item .stat-label {
    font-size: 14px;
    color: #aaa;
    margin-top: 8px;
}

/* Case Studies */
.case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.case-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    height: 300px;
}

.case-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.case-card:hover img {
    transform: scale(1.05);
}

.case-card .case-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 30px 20px 20px;
    background: linear-gradient(transparent, rgba(0,0,0,0.85));
    color: var(--white);
}

.case-card .case-overlay h3 {
    font-size: 18px;
    margin-bottom: 5px;
}

.case-card .case-overlay p {
    font-size: 13px;
    opacity: 0.8;
}

/* Certification */
.cert-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.cert-item {
    text-align: center;
    padding: 20px;
}

.cert-item img {
    height: 80px;
    margin-bottom: 10px;
}

.cert-item p {
    font-size: 13px;
    color: #666;
}

/* Video Section */
.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* Contact Form */
.contact-form {
    max-width: 700px;
    margin: 0 auto;
    background: var(--white);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    font-size: 14px;
    color: var(--text-color);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
    transition: border-color 0.3s;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--power-red);
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

/* Footer */
.site-footer {
    background: var(--pure-black);
    color: #aaa;
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 {
    color: var(--white);
    font-size: 16px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--power-red);
    display: inline-block;
}

.footer-col p {
    font-size: 14px;
    line-height: 2;
}

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

.footer-col ul li {
    margin-bottom: 8px;
}

.footer-col ul li a {
    color: #aaa;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-col ul li a:hover {
    color: var(--power-red);
}

.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 20px;
    text-align: center;
    font-size: 13px;
}

.footer-bottom a {
    color: #aaa;
    text-decoration: none;
}

/* Page Header */
.page-header {
    background: var(--dark-bg);
    padding: 80px 0 60px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(211,47,47,0.1), transparent);
}

.page-header h1 {
    color: var(--white);
    font-size: 36px;
    font-weight: 800;
    position: relative;
}

.page-header .breadcrumb {
    color: #aaa;
    font-size: 14px;
    margin-top: 10px;
    position: relative;
}

.page-header .breadcrumb a {
    color: var(--metal-gray);
    text-decoration: none;
}

/* Content Sections */
.content-block {
    padding: 40px 0;
}

.content-block h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: var(--pure-black);
}

.content-block h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--pure-black);
}

.content-block p {
    margin-bottom: 15px;
    font-size: 15px;
    line-height: 1.8;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    padding: 10px 0 10px 30px;
    position: relative;
    font-size: 15px;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--power-red);
    font-weight: 700;
}

/* Two Column Layout */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.two-col img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

/* Solutions Cards */
.solution-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
    margin-bottom: 30px;
    transition: all 0.3s;
}

.solution-card:hover {
    border-color: var(--power-red);
    box-shadow: 0 4px 20px rgba(211,47,47,0.1);
}

.solution-card h3 {
    color: var(--power-red);
    margin-bottom: 15px;
}

/* Table Styles */
.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.data-table th,
.data-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 14px;
}

.data-table th {
    background: var(--dark-bg);
    color: var(--white);
    font-weight: 600;
}

.data-table tr:hover {
    background: var(--light-gray);
}

/* Lazy Load */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s;
}

img[loading="lazy"].loaded,
img.loaded {
    opacity: 1;
}

/* Responsive */
@media (max-width: 768px) {
    .mobile-toggle {
        display: block;
    }

    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--pure-black);
        flex-direction: column;
        padding: 10px 0;
    }

    .main-nav.active {
        display: flex;
    }

    .hero {
        height: 400px;
    }

    .hero-content h1 {
        font-size: 28px;
    }

    .hero-content p {
        font-size: 16px;
    }

    .stats-row {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .two-col {
        grid-template-columns: 1fr;
    }

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

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

    .section {
        padding: 50px 0;
    }

    .section-title h2 {
        font-size: 26px;
    }

    .btn-outline {
        margin-left: 0;
        margin-top: 10px;
    }
}

@media (max-width: 480px) {
    .header-inner {
        padding: 10px 15px;
    }

    .logo-text {
        font-size: 16px;
    }

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