/* ==========================================================
   Huami Auto Parts — North American Premium Industrial Style
   ========================================================== */

:root {
    --primary: #1a1a2e;
    --primary-light: #16213e;
    --accent: #c8a84e;
    --accent-hover: #d4b85e;
    --accent-dark: #a88830;
    --dark: #0f0f1a;
    --text: #2c2c3a;
    --text-light: #6b7280;
    --bg-light: #f8f7f4;
    --bg-white: #ffffff;
    --border: #e5e7eb;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text);
    line-height: 1.7;
    background: var(--bg-light);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* === Typography === */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--primary);
}

.text-accent {
    color: var(--accent);
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 15px;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    letter-spacing: 0.3px;
}

.btn-primary {
    background: var(--accent);
    color: var(--dark);
    border-color: var(--accent);
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(200,168,78,0.35);
}

.btn-outline {
    background: transparent;
    color: var(--bg-white);
    border-color: rgba(255,255,255,0.4);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: var(--bg-white);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* === Navigation === */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: transparent;
    padding: 16px 0;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(15,15,26,0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 10px 0;
    box-shadow: 0 2px 30px rgba(0,0,0,0.3);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.logo-mark {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    background: var(--accent);
    color: var(--dark);
    font-weight: 800;
    font-size: 22px;
    border-radius: 8px;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-name {
    font-weight: 800;
    font-size: 20px;
    letter-spacing: 3px;
    color: var(--bg-white);
    line-height: 1.1;
}

.logo-tagline {
    font-size: 11px;
    letter-spacing: 2px;
    color: rgba(255,255,255,0.6);
    text-transform: uppercase;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-links a {
    text-decoration: none;
    color: rgba(255,255,255,0.8);
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 0.5px;
    transition: var(--transition);
    position: relative;
    padding-bottom: 4px;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--bg-white);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 28px;
    height: 2px;
    background: var(--bg-white);
    transition: var(--transition);
    border-radius: 2px;
}

/* === Section Common === */
.section {
    padding: 100px 0;
}

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

.section-label {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
    background: rgba(200,168,78,0.1);
    padding: 6px 16px;
    border-radius: 20px;
}

.section-header h2 {
    font-size: 40px;
    margin-bottom: 16px;
    font-family: 'Playfair Display', serif;
    font-weight: 600;
}

.divider {
    width: 60px;
    height: 3px;
    background: var(--accent);
    margin: 0 auto 20px;
    border-radius: 2px;
}

.section-desc {
    max-width: 640px;
    margin: 0 auto;
    color: var(--text-light);
    font-size: 17px;
}

/* === Hero === */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: var(--dark);
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(200,168,78,0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(255,255,255,0.03) 0%, transparent 50%),
        linear-gradient(135deg, var(--dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.03'/%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 120px 0 60px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--accent);
    background: rgba(200,168,78,0.12);
    border: 1px solid rgba(200,168,78,0.2);
    padding: 8px 20px;
    border-radius: 50px;
    margin-bottom: 32px;
}

.hero h1 {
    font-size: clamp(36px, 6vw, 68px);
    color: var(--bg-white);
    font-family: 'Playfair Display', serif;
    font-weight: 600;
    line-height: 1.1;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: clamp(16px, 2vw, 19px);
    color: rgba(255,255,255,0.6);
    max-width: 640px;
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 64px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    padding: 32px 0;
    border-top: 1px solid rgba(255,255,255,0.08);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-number {
    font-size: 36px;
    font-weight: 800;
    color: var(--bg-white);
    font-family: 'Playfair Display', serif;
}

.stat-plus {
    font-size: 24px;
    color: var(--accent);
    font-weight: 700;
}

.stat-label {
    font-size: 13px;
    color: rgba(255,255,255,0.5);
    letter-spacing: 1px;
    text-transform: uppercase;
}

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

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.about-intro {
    font-size: 18px;
    font-weight: 500;
    color: var(--primary);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-content p {
    margin-bottom: 16px;
    color: var(--text-light);
}

.about-highlights {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 32px;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    background: var(--bg-light);
    padding: 12px 16px;
    border-radius: var(--radius-sm);
}

.highlight-icon {
    font-size: 18px;
}

.about-img-wrapper {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.about-img-wrapper img {
    width: 100%;
    height: 450px;
    object-fit: cover;
    display: block;
}

.about-img-badge {
    position: absolute;
    bottom: 20px;
    left: 20px;
    background: var(--accent);
    color: var(--dark);
    font-weight: 700;
    font-size: 14px;
    padding: 8px 20px;
    border-radius: 6px;
    letter-spacing: 1px;
}

/* === Products === */
.products {
    background: var(--bg-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

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

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

.product-icon {
    font-size: 36px;
    margin-bottom: 16px;
}

.product-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--primary);
    font-family: 'Playfair Display', serif;
}

.product-card p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.7;
}

.product-specs {
    list-style: none;
    padding: 0;
}

.product-specs li {
    font-size: 13px;
    color: var(--text);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.product-specs li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 600;
}

.products-cta {
    text-align: center;
    padding: 40px;
    background: var(--primary);
    border-radius: var(--radius);
    color: var(--bg-white);
}

.products-cta p {
    font-size: 18px;
    margin-bottom: 24px;
    color: rgba(255,255,255,0.8);
}

/* === Quality === */
.quality {
    background: var(--bg-white);
}

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

.quality-card {
    display: flex;
    gap: 20px;
    background: var(--bg-light);
    padding: 24px;
    border-radius: var(--radius);
    transition: var(--transition);
}

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

.quality-icon {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    flex-shrink: 0;
}

.quality-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.quality-info h3 {
    font-size: 16px;
    margin-bottom: 6px;
    color: var(--primary);
}

.quality-info p {
    font-size: 13px;
    color: var(--text-light);
    line-height: 1.6;
}

/* === Factory Tour === */
.factory {
    background: var(--bg-light);
}

.factory-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.factory-item {
    position: relative;
    border-radius: var(--radius-sm);
    overflow: hidden;
    aspect-ratio: 4/3;
    cursor: pointer;
}

.factory-item-wide {
    grid-column: span 2;
    grid-row: span 2;
    aspect-ratio: auto;
}

.factory-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.factory-item:hover img {
    transform: scale(1.08);
}

.factory-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(transparent 60%, rgba(15,15,26,0.9));
    display: flex;
    align-items: flex-end;
    padding: 16px;
    opacity: 0;
    transition: var(--transition);
}

.factory-item:hover .factory-overlay {
    opacity: 1;
}

.factory-overlay span {
    color: var(--bg-white);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

/* === Why Us === */
.why-us {
    background: var(--primary);
    color: var(--bg-white);
}

.why-us .section-header h2 {
    color: var(--bg-white);
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.why-card {
    padding: 32px;
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: var(--radius);
    transition: var(--transition);
}

.why-card:hover {
    background: rgba(255,255,255,0.04);
    border-color: rgba(200,168,78,0.3);
}

.why-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--accent);
    font-family: 'Playfair Display', serif;
    line-height: 1;
    margin-bottom: 16px;
    opacity: 0.6;
}

.why-card h3 {
    font-size: 20px;
    color: var(--bg-white);
    margin-bottom: 12px;
}

.why-card p {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
    line-height: 1.7;
}

/* === Contact === */
.contact {
    background: var(--bg-white);
}

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

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-card {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 20px;
    background: var(--bg-light);
    border-radius: var(--radius-sm);
}

.contact-icon {
    font-size: 24px;
    margin-top: 2px;
}

.contact-card h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--primary);
}

.contact-card p {
    font-size: 14px;
    color: var(--text-light);
}

.contact-card a {
    color: var(--accent-dark);
    text-decoration: none;
    font-weight: 500;
}

.contact-card a:hover {
    color: var(--accent);
}

.contact-note {
    background: rgba(200,168,78,0.1);
    border-left: 3px solid var(--accent);
    padding: 16px 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.contact-note p {
    font-size: 14px;
    color: var(--text);
}

.contact-form {
    background: var(--bg-light);
    padding: 36px;
    border-radius: var(--radius);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

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

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 6px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    font-family: inherit;
    background: var(--bg-white);
    color: var(--text);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(200,168,78,0.15);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #b0b0b0;
}

/* === Footer === */
.footer {
    background: var(--dark);
    color: rgba(255,255,255,0.6);
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand p {
    font-size: 14px;
    margin-top: 16px;
    line-height: 1.8;
}

.footer-links h4,
.footer-contact h4 {
    color: var(--bg-white);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: 1px;
    text-transform: uppercase;
}

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

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

.footer-links a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-contact p {
    font-size: 14px;
    margin-bottom: 8px;
}

.footer-contact a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    transition: var(--transition);
}

.footer-contact a:hover {
    color: var(--accent);
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.06);
    padding: 20px 0;
    text-align: center;
}

.footer-bottom p {
    font-size: 13px;
    color: rgba(255,255,255,0.3);
}

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(15,15,26,0.98);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        backdrop-filter: blur(20px);
    }

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

    .nav-toggle {
        display: flex;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

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

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

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

    .factory-item-wide {
        grid-column: span 2;
    }

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

    .section-header h2 {
        font-size: 28px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .hero-actions .btn {
        width: 100%;
        justify-content: center;
    }

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

    .contact-form {
        padding: 24px;
    }

    .about-highlights {
        grid-template-columns: 1fr;
    }

    .quality-card {
        flex-direction: column;
    }

    .quality-icon {
        width: 100%;
        height: 180px;
    }
}

@media (max-width: 480px) {
    .factory-grid {
        grid-template-columns: 1fr;
    }

    .factory-item-wide {
        grid-column: span 1;
    }

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

/* === Scroll Animation === */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}