/* -------------------------------------------------------------
 * CSS DESIGN SYSTEM & STYLING
 * HONGKONG XIANGLU TRADING CO., LTD
 * ------------------------------------------------------------- */

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

:root {
    /* Color Palette (Luxury Dark & Gold) */
    --bg-900: hsl(220, 25%, 8%);
    --bg-800: hsl(220, 22%, 11%);
    --bg-700: hsl(220, 18%, 15%);
    --bg-600: hsl(220, 15%, 22%);
    --text-primary: hsl(220, 15%, 92%);
    --text-secondary: hsl(220, 10%, 68%);
    --text-muted: hsl(220, 8%, 48%);
    
    --accent-gold: hsl(38, 55%, 58%);
    --accent-gold-hover: hsl(38, 65%, 48%);
    --accent-gold-glow: hsla(38, 55%, 58%, 0.15);
    --accent-gold-light: hsl(38, 60%, 85%);
    
    --glass-bg: rgba(14, 18, 24, 0.75);
    --glass-border: rgba(255, 255, 255, 0.06);
    --card-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    --gold-gradient: linear-gradient(135deg, hsl(38, 55%, 58%) 0%, hsl(28, 65%, 50%) 100%);
    
    /* Typography */
    --font-title: 'Playfair Display', Georgia, serif;
    --font-body: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    
    /* Transitions & Layout */
    --transition-smooth: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: all 0.2s ease;
    --border-radius-sm: 8px;
    --border-radius-md: 16px;
    --border-radius-lg: 24px;
    --container-width: 1200px;
    --header-height: 80px;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    background-color: var(--bg-900);
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-900);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Typography elements */
h1, h2, h3, h4 {
    font-family: var(--font-title);
    font-weight: 600;
    line-height: 1.25;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

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

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-900);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-700);
    border-radius: 5px;
    border: 2px solid var(--bg-900);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-gold);
}

/* Layout Utilities */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

section {
    padding: 100px 0;
    position: relative;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: var(--border-radius-sm);
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.95rem;
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.btn-primary {
    background: var(--gold-gradient);
    color: var(--bg-900);
    border: none;
    box-shadow: 0 4px 15px rgba(212, 163, 89, 0.3);
    font-weight: 600;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(212, 163, 89, 0.45);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-gold);
    transform: translateY(-2px);
}

.btn-block {
    display: flex;
    width: 100%;
}

.btn-text {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--accent-gold);
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 12px;
}

.btn-text .arrow-icon {
    width: 16px;
    height: 16px;
    transition: var(--transition-smooth);
}

.btn-text:hover {
    color: var(--accent-gold-light);
}

.btn-text:hover .arrow-icon {
    transform: translateX(6px);
}

/* Header & Navbar */
.header {
    height: var(--header-height);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    transition: var(--transition-smooth);
}

.header.scrolled {
    height: 70px;
    background: hsl(220, 25%, 6%);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    font-family: var(--font-body);
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: 2px;
    color: var(--text-primary);
}

.logo-accent {
    color: var(--accent-gold);
    background: var(--gold-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 400;
    padding: 8px 0;
    position: relative;
}

.nav-link:hover {
    color: var(--text-primary);
}

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

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

.nav-link.active {
    color: var(--text-primary);
    font-weight: 500;
}

.btn-nav {
    border: 1px solid var(--accent-gold);
    padding: 8px 20px;
    border-radius: var(--border-radius-sm);
    color: var(--accent-gold);
}

.btn-nav:hover {
    background: var(--accent-gold);
    color: var(--bg-900);
}

.btn-nav::after {
    display: none;
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.mobile-nav-toggle .bar {
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition-smooth);
}

/* Mobile Menu Active State (Hamburger to X) */
.mobile-nav-toggle.open .bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-nav-toggle.open .bar:nth-child(2) {
    opacity: 0;
}

.mobile-nav-toggle.open .bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Mobile Nav Overlay */
.mobile-nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--bg-900);
    z-index: 999;
    display: flex;
    justify-content: center;
    align-items: center;
    transform: translateY(-100%);
    transition: var(--transition-smooth);
    opacity: 0;
}

.mobile-nav-overlay.open {
    transform: translateY(0);
    opacity: 1;
}

.mobile-nav-list {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 32px;
}

.mobile-nav-link {
    font-size: 1.8rem;
    font-family: var(--font-title);
    color: var(--text-secondary);
}

.mobile-nav-link:hover {
    color: var(--accent-gold);
}

/* Hero Section */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: calc(var(--header-height) + 40px);
    overflow: hidden;
}

.hero-bg-accent {
    position: absolute;
    top: -10%;
    right: -10%;
    width: 50%;
    height: 70%;
    background: radial-gradient(circle, rgba(212, 163, 89, 0.08) 0%, rgba(0,0,0,0) 70%);
    z-index: 1;
    pointer-events: none;
}

.hero-container {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 48px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-badge {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(212, 163, 89, 0.1);
    color: var(--accent-gold);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    border-radius: 50px;
    border: 1px solid rgba(212, 163, 89, 0.2);
    margin-bottom: 24px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--text-primary) 50%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 550px;
    font-weight: 300;
}

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

/* Hero Visual Graphic */
.hero-visual-wrapper {
    display: flex;
    justify-content: center;
    position: relative;
}

.hero-visual-card {
    position: relative;
    width: 100%;
    max-width: 420px;
    aspect-ratio: 1;
    background: var(--bg-800);
    border-radius: var(--border-radius-lg);
    padding: 16px;
    border: 1px solid var(--glass-border);
    box-shadow: var(--card-shadow);
}

.hero-image-frame {
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius-md);
    overflow: hidden;
    position: relative;
}

.hero-image-frame::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(14, 18, 24, 0.5) 0%, transparent 50%);
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-smooth);
}

.visual-badge {
    position: absolute;
    bottom: -24px;
    left: -24px;
    background: var(--bg-800);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.4);
    backdrop-filter: blur(10px);
}

.badge-icon {
    width: 32px;
    height: 32px;
    color: var(--accent-gold);
}

.badge-title {
    display: block;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

.badge-subtitle {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Float Animation */
.float-anim {
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
    100% { transform: translateY(0px); }
}

/* Sections Header */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 64px auto;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    color: var(--accent-gold);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.section-tag.text-light {
    color: var(--accent-gold-light);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 20px;
    font-weight: 500;
}

.section-title.text-light {
    color: #fff;
}

.section-description {
    color: var(--text-secondary);
    font-size: 1.05rem;
    font-weight: 300;
}

/* Overview / Pillars */
.pillars-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.pillar-card {
    background: var(--bg-800);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-md);
    padding: 40px;
    transition: var(--transition-smooth);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.pillar-card:hover {
    transform: translateY(-8px);
    border-color: rgba(212, 163, 89, 0.3);
    box-shadow: 0 20px 40px rgba(212, 163, 89, 0.05);
}

.pillar-icon-wrapper {
    width: 60px;
    height: 60px;
    border-radius: var(--border-radius-sm);
    background: rgba(212, 163, 89, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    color: var(--accent-gold);
    transition: var(--transition-smooth);
}

.pillar-icon {
    width: 28px;
    height: 28px;
}

.pillar-card:hover .pillar-icon-wrapper {
    background: var(--accent-gold);
    color: var(--bg-900);
}

.pillar-title {
    font-size: 1.4rem;
    font-weight: 500;
    margin-bottom: 16px;
}

.pillar-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
}

/* Products Section */
.products-section {
    background-color: var(--bg-800);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.product-card {
    background: var(--bg-900);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: var(--transition-smooth);
}

.product-card:hover {
    transform: translateY(-6px);
    border-color: rgba(212, 163, 89, 0.25);
    box-shadow: var(--card-shadow);
}

.product-image-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16/10;
    overflow: hidden;
}

.product-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.product-overlay {
    position: absolute;
    top: 20px;
    left: 20px;
}

.product-tag {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
    padding: 6px 12px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--accent-gold);
}

.product-info {
    padding: 32px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.product-title {
    font-size: 1.75rem;
    font-weight: 500;
    margin-bottom: 12px;
}

.product-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
    margin-bottom: 24px;
}

/* Product Specifications Table */
.product-specs {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 24px;
    font-size: 0.85rem;
    margin-top: auto;
}

.product-specs tr {
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.product-specs tr:last-child {
    border-bottom: none;
}

.product-specs th {
    text-align: left;
    padding: 8px 0;
    color: var(--text-muted);
    font-weight: 400;
    width: 35%;
}

.product-specs td {
    text-align: right;
    padding: 8px 0;
    color: var(--text-primary);
    font-weight: 500;
}

/* Contact Section */
.contact-section {
    background: radial-gradient(circle at 10% 20%, rgba(212, 163, 89, 0.05) 0%, rgba(0,0,0,0) 60%), var(--bg-900);
}

.contact-container {
    display: grid;
    grid-template-columns: 0.95fr 1.05fr;
    gap: 64px;
    align-items: center;
}

.contact-info-block {
    display: flex;
    flex-direction: column;
}

.contact-info-description {
    color: var(--text-secondary);
    font-size: 1.05rem;
    font-weight: 300;
    margin-bottom: 40px;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.contact-detail-item {
    display: flex;
    align-items: center;
    gap: 20px;
}

.contact-detail-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(212, 163, 89, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-gold);
    flex-shrink: 0;
    border: 1px solid rgba(212, 163, 89, 0.15);
}

.contact-detail-icon svg {
    width: 20px;
    height: 20px;
}

.contact-detail-label {
    font-family: var(--font-body);
    font-size: 0.8rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.contact-detail-value {
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
}

a.contact-detail-value:hover {
    color: var(--accent-gold);
    text-decoration: underline;
}

/* Contact Form Block */
.contact-form-block {
    background: var(--bg-800);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-lg);
    padding: 48px;
    box-shadow: var(--card-shadow);
}

.form-title {
    font-size: 1.8rem;
    font-weight: 500;
    margin-bottom: 8px;
}

.form-subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
    margin-bottom: 32px;
}

.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.form-input {
    width: 100%;
    background: var(--bg-700);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    padding: 12px 16px;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: var(--transition-smooth);
}

.form-input::placeholder {
    color: var(--text-muted);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-gold);
    box-shadow: 0 0 0 3px rgba(212, 163, 89, 0.15);
    background: var(--bg-600);
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23d4a359' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 16px;
    padding-right: 48px;
}

.form-textarea {
    resize: vertical;
}

.form-status {
    margin-top: 16px;
    font-size: 0.9rem;
    text-align: center;
    font-weight: 500;
}

.form-status.success {
    color: #4caf50;
}

.form-status.error {
    color: #f44336;
}

/* Footer Section */
.footer {
    background: hsl(220, 25%, 5%);
    border-top: 1px solid var(--glass-border);
    padding-top: 80px;
}

.footer-container {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1.5fr;
    gap: 64px;
    padding-bottom: 60px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
}

.footer-logo {
    font-size: 1.4rem;
    margin-bottom: 20px;
}

.footer-tagline {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
    max-width: 320px;
}

.footer-title {
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent-gold);
    margin-bottom: 24px;
}

.footer-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.footer-link:hover {
    color: var(--text-primary);
    transform: translateX(4px);
    display: inline-block;
}

.footer-contact {
    display: flex;
    flex-direction: column;
}

.footer-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 12px;
}

.footer-link-value {
    color: var(--text-primary);
    font-weight: 500;
}

.footer-link-value:hover {
    color: var(--accent-gold);
}

.footer-bottom {
    border-top: 1px solid var(--glass-border);
    padding: 30px 0;
}

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

.copyright-text, .footer-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Intersection Observer Animations */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Media Queries */

@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: 64px;
        text-align: center;
    }
    
    .hero-subtitle {
        margin-inline: auto;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-visual-wrapper {
        margin-top: 20px;
    }
    
    .pillars-grid {
        grid-template-columns: 1fr;
        gap: 24px;
        max-width: 600px;
        margin: 0 auto;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
        gap: 32px;
        max-width: 600px;
        margin: 0 auto;
    }
    
    .contact-container {
        grid-template-columns: 1fr;
        gap: 64px;
    }
    
    .footer-container {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
    
    .footer-brand {
        grid-column: span 2;
        margin-bottom: 20px;
    }
}

@media (max-width: 768px) {
    section {
        padding: 60px 0;
    }
    
    .mobile-nav-toggle {
        display: flex;
    }
    
    .nav {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .contact-form-block {
        padding: 32px 24px;
    }
    
    .footer-container {
        grid-template-columns: 1fr;
    }
    
    .footer-brand {
        grid-column: span 1;
    }
    
    .footer-bottom-container {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    
    .visual-badge {
        bottom: -16px;
        left: 0;
        right: 0;
        margin: 0 auto;
        width: max-content;
    }
}