/* ============================================================
   湖北省赛麟科技有限公司 — 三语外贸官网 样式表
   Hubei Sailin Technology — Trilingual Website Stylesheet
   ============================================================ */

/* --- CSS Variables --- */
:root {
    --primary: #0d2b4a;
    --primary-light: #1a4270;
    --primary-lighter: #26588a;
    --accent: #c8963e;
    --accent-light: #e0b866;
    --cta: #E67E22;
    --cta-hover: #F0A030;
    --cta-dark: #d35400;
    --white: #ffffff;
    --gray-50: #f8f9fb;
    --gray-100: #eef0f4;
    --gray-200: #d1d5dc;
    --gray-400: #8b95a5;
    --gray-600: #4a5568;
    --gray-800: #1e293b;
    --text: #1e293b;
    --text-light: #64748b;
    --radius: 8px;
    --radius-lg: 16px;
    --shadow: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 24px rgba(0,0,0,0.10);
    --shadow-lg: 0 12px 48px rgba(0,0,0,0.12);
    --transition: 0.3s ease;
    --max-width: 1200px;
    --header-h: 72px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    color: var(--text);
    background: var(--white);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

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

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--primary);
    text-align: center;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-light);
    text-align: center;
    margin-bottom: 48px;
}

/* --- Header / Navigation --- */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--header-h);
    background: rgba(13,43,74,0.96);
    backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    transition: var(--transition);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.3px;
}

.logo-icon {
    width: 36px; height: 36px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 800;
}

.nav-links {
    display: flex;
    gap: 6px;
    align-items: center;
}

.nav-links a {
    color: rgba(255,255,255,0.75);
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.92rem;
    font-weight: 500;
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--white);
    background: rgba(255,255,255,0.08);
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    gap: 2px;
    background: rgba(255,255,255,0.06);
    border-radius: 8px;
    padding: 3px;
    margin-left: 12px;
}

.lang-btn {
    padding: 6px 12px;
    border: none;
    background: transparent;
    color: rgba(255,255,255,0.7);
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.82rem;
    font-weight: 500;
    transition: var(--transition);
    white-space: nowrap;
}

.lang-btn:hover { color: var(--white); background: rgba(255,255,255,0.06); }

.lang-btn.active {
    background: var(--accent);
    color: var(--primary);
    font-weight: 600;
}

/* Mobile Menu Button */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    color: var(--white);
    font-size: 1.5rem;
}

/* --- Hero Section --- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: url('../img/hero-refinery-bg.png') center/cover no-repeat;
    position: relative;
    overflow: hidden;
    padding: 120px 24px 80px;
}

/* Dark overlay for hero background image */
.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(13,43,74,0.88) 0%, rgba(13,43,74,0.78) 40%, rgba(13,43,74,0.70) 100%);
    z-index: 0;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background: radial-gradient(circle at 30% 60%, rgba(230,126,34,0.10) 0%, transparent 50%),
                radial-gradient(circle at 70% 20%, rgba(230,126,34,0.06) 0%, transparent 40%);
    animation: heroBg 20s ease-in-out infinite alternate;
    z-index: 1;
}

@keyframes heroBg {
    0% { transform: translate(0, 0); }
    100% { transform: translate(20px, -20px); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    padding: 6px 20px;
    background: rgba(230,126,34,0.12);
    border: 1px solid rgba(230,126,34,0.25);
    border-radius: 50px;
    color: var(--cta-hover);
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 28px;
}

.hero-title {
    font-size: 3.2rem;
    font-weight: 800;
    color: var(--white);
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: rgba(255,255,255,0.65);
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
}

.btn-primary {
    background: var(--cta);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--cta-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(230,126,34,0.35);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255,255,255,0.2);
}

.btn-outline:hover {
    border-color: var(--white);
    background: rgba(255,255,255,0.05);
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255,255,255,0.4);
    font-size: 0.8rem;
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

/* --- About Section --- */
.about {
    background: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 16px;
    font-size: 1rem;
    line-height: 1.8;
}

.about-text p:last-child { margin-bottom: 0; }

.about-image {
    position: relative;
}

.about-image-placeholder {
    width: 100%;
    aspect-ratio: 4/3;
    background: url('../img/about-facility.png') center/cover no-repeat;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.stat-card {
    text-align: center;
    padding: 24px 12px;
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.stat-num {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 6px;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 500;
}

/* --- Products Section --- */
.products {
    background: var(--gray-50);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.product-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid transparent;
}

.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

/* --- Product Card Image --- */
.product-img-wrap {
    width: 100%;
    aspect-ratio: 4/3;
    border-radius: var(--radius);
    overflow: hidden;
    margin-bottom: 20px;
    background: var(--gray-50);
}

.product-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

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

/* --- Product Icon (fallback) --- */
.product-icon {
    width: 56px; height: 56px;
    background: var(--gray-50);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    margin-bottom: 20px;
}

.product-name {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 12px;
}

.product-desc {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 20px;
}

.product-features {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.feature-tag {
    padding: 4px 12px;
    background: var(--gray-50);
    border-radius: 20px;
    font-size: 0.8rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Product Specs Toggle */
.btn-spec-toggle {
    display: inline-block;
    margin-top: 16px;
    padding: 6px 18px;
    background: transparent;
    border: 1px solid var(--gray-200);
    border-radius: 6px;
    color: var(--primary-light);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.btn-spec-toggle:hover {
    border-color: var(--cta);
    color: var(--cta);
    background: rgba(230,126,34,0.05);
}

.btn-spec-toggle.active {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--white);
}

.product-specs {
    margin-top: 14px;
    padding: 14px;
    background: var(--gray-50);
    border-radius: var(--radius);
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-6px); }
    to { opacity: 1; transform: translateY(0); }
}

.spec-table {
    width: 100%;
    border-collapse: collapse;
}

.spec-table td {
    padding: 6px 0;
    font-size: 0.85rem;
    border-bottom: 1px solid var(--gray-100);
}

.spec-table tr:last-child td {
    border-bottom: none;
}

.spec-label {
    color: var(--text-light);
    font-weight: 500;
    width: 40%;
}

.spec-value {
    color: var(--primary);
    font-weight: 600;
    text-align: right;
}

/* --- Advantages Section --- */
.advantages {
    background: var(--white);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.advantage-card {
    padding: 32px 24px;
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.advantage-card:hover {
    border-left-color: var(--accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.advantage-icon-symbol {
    font-size: 1.8rem;
    margin-bottom: 14px;
}

.advantage-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.advantage-desc {
    font-size: 0.92rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* --- Contact Section --- */
.contact {
    background: var(--primary);
    color: var(--white);
}

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

.contact .section-subtitle {
    color: rgba(255,255,255,0.55);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 48px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 14px;
}

.contact-item-icon {
    width: 44px; height: 44px;
    background: rgba(255,255,255,0.06);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.contact-item-text h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: rgba(255,255,255,0.9);
    margin-bottom: 2px;
}

.contact-item-text p {
    font-size: 0.9rem;
    color: rgba(255,255,255,0.55);
}

/* Contact Form */
.contact-form {
    background: var(--primary-light);
    border-radius: var(--radius-lg);
    padding: 32px;
    border: 1px solid rgba(255,255,255,0.06);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 0.88rem;
    font-weight: 500;
    color: rgba(255,255,255,0.7);
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius);
    color: var(--white);
    font-size: 0.95rem;
    font-family: inherit;
    transition: var(--transition);
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255,255,255,0.08);
}

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

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: rgba(255,255,255,0.25);
}

/* --- Certifications Section --- */
.certifications {
    background: var(--gray-50);
}

.certs-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.cert-card {
    text-align: center;
    padding: 28px 20px;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.cert-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.cert-icon {
    font-size: 2.2rem;
    margin-bottom: 12px;
}

.cert-card h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
}

.cert-card p {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* --- Footer --- */
.footer {
    background: var(--primary);
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
}

.footer-col-title {
    color: rgba(255,255,255,0.9);
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: 0.3px;
}

/* Footer Logo */
.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo-icon {
    width: 36px; height: 36px;
    background: var(--cta);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--white);
    font-weight: 800;
}

.footer-logo-text {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.3px;
}

.footer-desc {
    color: rgba(255,255,255,0.45);
    font-size: 0.88rem;
    line-height: 1.7;
    margin-bottom: 12px;
    max-width: 360px;
}

.footer-domain {
    color: rgba(255,255,255,0.25);
    font-size: 0.82rem;
    font-family: monospace;
}

/* Footer Nav */
.footer-nav {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-nav li a {
    color: rgba(255,255,255,0.45);
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-nav li a:hover {
    color: var(--cta);
    padding-left: 4px;
}

/* Footer Contact */
.footer-contact {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-contact li {
    color: rgba(255,255,255,0.45);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Footer Bottom */
.footer-bottom {
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255,255,255,0.3);
    font-size: 0.82rem;
}

/* --- Scroll Animations --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

.stagger-1 { transition-delay: 0s; }
.stagger-2 { transition-delay: 0.1s; }
.stagger-3 { transition-delay: 0.2s; }
.stagger-4 { transition-delay: 0.3s; }
.stagger-5 { transition-delay: 0.4s; }
.stagger-6 { transition-delay: 0.5s; }

/* --- Mobile Menu --- */
@media (max-width: 768px) {
    :root { --header-h: 60px; }

    .menu-toggle {
        display: block;
    }

    .nav-links {
        position: fixed;
        top: var(--header-h);
        left: 0; right: 0;
        background: var(--primary);
        flex-direction: column;
        padding: 16px;
        gap: 4px;
        display: none;
        border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links a {
        padding: 12px 16px;
        font-size: 1rem;
    }

    .lang-switcher {
        margin: 8px 0 0;
        align-self: center;
    }

    .hero-title { font-size: 2rem; }
    .hero-subtitle { font-size: 0.95rem; }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

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

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

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

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

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
        text-align: center;
    }

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

    .footer-desc { max-width: 100%; margin: 0 auto 12px; }
    .footer-logo { justify-content: center; }
    .footer-contact li { justify-content: center; }

    .section-title { font-size: 1.7rem; }
    .section { padding: 56px 0; }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .advantages-grid { grid-template-columns: repeat(2, 1fr); }
    .about-grid { grid-template-columns: 1fr; gap: 32px; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 40px; }
}