/* ============================================
   JY ChemSource — Main Stylesheet
   Chemical Foreign Trade Website
   ============================================ */

/* --- CSS Variables / Design Tokens --- */
:root {
    --primary: #0d47a1;
    --primary-light: #1565c0;
    --primary-lighter: #1976d2;
    --primary-soft: #e3f2fd;
    --accent: #00897b;
    --accent-light: #00acc1;
    --accent-soft: #e0f2f1;

    --bg: #f8fafc;
    --bg-white: #ffffff;
    --bg-dark: #0f172a;
    --bg-card: #ffffff;

    --text: #1e293b;
    --text-light: #475569;
    --text-muted: #94a3b8;
    --text-white: #f1f5f9;

    --border: #e2e8f0;
    --border-light: #f1f5f9;

    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.10), 0 4px 10px rgba(0,0,0,0.06);
    --shadow-xl: 0 20px 50px rgba(0,0,0,0.12);

    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);

    --max-width: 1200px;
    --nav-height: 72px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

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

ul { list-style: none; }

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

/* --- Section Container --- */
.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section-header {
    text-align: center;
    margin-bottom: 56px;
}

.section-badge {
    display: inline-block;
    padding: 6px 16px;
    background: var(--primary-soft);
    color: var(--primary);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: 50px;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.8rem, 3.5vw, 2.6rem);
    font-weight: 800;
    color: var(--bg-dark);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.section-desc {
    max-width: 640px;
    margin: 0 auto;
    color: var(--text-light);
    font-size: 1.05rem;
    line-height: 1.7;
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height);
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--bg-dark);
}

.logo-icon { font-size: 1.5rem; }

.nav-logo strong { color: var(--primary); }

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

.nav-link {
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-light);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

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

.nav-link.active { color: var(--primary); font-weight: 600; }

.nav-link.cta-nav {
    background: var(--primary);
    color: white !important;
    padding: 8px 20px;
    border-radius: 50px;
    margin-left: 8px;
}

.nav-link.cta-nav:hover { background: var(--primary-light); }

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

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2.5px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ============================================
   HERO
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #0a1929 0%, #0d47a1 40%, #00897b 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 20% 50%, rgba(0,137,123,0.25) 0%, transparent 70%),
        radial-gradient(ellipse 60% 80% at 80% 30%, rgba(13,71,161,0.30) 0%, transparent 70%);
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 200px;
    background: linear-gradient(to top, var(--bg), transparent);
    pointer-events: none;
}

/* Grid pattern overlay */
.hero-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none;
}

.hero-container {
    position: relative;
    z-index: 1;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 120px 24px 80px;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(255,255,255,0.12);
    color: rgba(255,255,255,0.9);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 28px;
    letter-spacing: 0.04em;
}

.hero-title {
    font-size: clamp(2.2rem, 5vw, 3.8rem);
    font-weight: 800;
    color: white;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
}

.gradient-text {
    background: linear-gradient(135deg, #64b5f6, #4dd0e1, #80cbc4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1rem, 1.8vw, 1.15rem);
    color: rgba(255,255,255,0.75);
    max-width: 640px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 56px;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 50px;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-family: inherit;
}

.btn-primary {
    background: white;
    color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid rgba(255,255,255,0.35);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.6);
}

.hero-stats {
    display: flex;
    gap: 48px;
    justify-content: center;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.2rem;
    font-weight: 800;
    color: white;
    letter-spacing: -0.02em;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.65);
    margin-top: 4px;
}

/* ============================================
   PRODUCTS SECTION
   ============================================ */
.products {
    padding: 100px 0;
    background: var(--bg-white);
}

/* --- Product Tabs --- */
.product-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-bottom: 40px;
}

.tab-btn {
    padding: 10px 20px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-light);
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    white-space: nowrap;
}

.tab-btn:hover {
    background: var(--primary-soft);
    color: var(--primary);
    border-color: transparent;
}

.tab-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    font-weight: 600;
    box-shadow: var(--shadow-md);
}

/* --- Product Panels --- */
.product-panels { position: relative; }

.product-panel {
    display: none;
    animation: fadeSlideIn 0.4s ease;
}

.product-panel.active { display: block; }

@keyframes fadeSlideIn {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.panel-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 28px;
    padding: 20px 24px;
    background: var(--bg);
    border-radius: var(--radius);
    border-left: 4px solid var(--primary);
}

.panel-icon { font-size: 2rem; flex-shrink: 0; }

.panel-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--bg-dark);
}

.panel-header h3 em {
    font-style: normal;
    font-weight: 400;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-left: 6px;
}

.panel-header p {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 2px;
}

/* --- Product Grid --- */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
}

.product-card {
    position: relative;
    padding: 18px 20px;
    background: var(--bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.product-card:hover {
    border-color: var(--primary-lighter);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.product-card .formula {
    font-family: 'Courier New', monospace;
    font-size: 0.75rem;
    color: var(--accent);
    font-weight: 600;
    letter-spacing: 0.04em;
}

.product-card strong {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--bg-dark);
    margin-bottom: 2px;
}

.product-card small {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.product-card .tag {
    display: inline-block;
    margin-top: 6px;
    padding: 3px 10px;
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--primary);
    background: var(--primary-soft);
    border-radius: 50px;
    align-self: flex-start;
}

/* ============================================
   SERVICES
   ============================================ */
.services {
    padding: 100px 0;
    background: var(--bg);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 24px;
}

.service-card {
    padding: 32px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.service-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: transparent;
    transform: translateY(-3px);
}

.service-icon { font-size: 2.2rem; margin-bottom: 16px; }

.service-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--bg-dark);
}

.service-card p {
    font-size: 0.92rem;
    color: var(--text-light);
    line-height: 1.65;
}

/* ============================================
   ADVANTAGES
   ============================================ */
.advantages {
    padding: 100px 0;
    background: var(--bg-white);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 32px;
}

.advantage-item {
    padding-left: 20px;
    border-left: 3px solid var(--border);
    transition: var(--transition);
}

.advantage-item:hover { border-left-color: var(--primary); }

.advantage-number {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
    letter-spacing: 0.08em;
}

.advantage-item h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--bg-dark);
}

.advantage-item p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* ============================================
   PROJECTS
   ============================================ */
.projects {
    padding: 100px 0;
    background: var(--bg);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 24px;
}

.project-card {
    padding: 32px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.project-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.project-tag {
    display: inline-block;
    padding: 4px 12px;
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--accent-soft);
    color: var(--accent);
    border-radius: 4px;
    margin-bottom: 14px;
}

.project-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 10px;
    line-height: 1.4;
}

.project-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.65;
    margin-bottom: 16px;
}

.project-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ============================================
   ABOUT
   ============================================ */
.about {
    padding: 100px 0;
    background: var(--bg-white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: start;
}

.about-text h2 {
    font-size: clamp(1.6rem, 2.8vw, 2.2rem);
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.25;
    letter-spacing: -0.02em;
}

.about-text p {
    font-size: 0.98rem;
    color: var(--text-light);
    line-height: 1.75;
    margin-bottom: 16px;
}

.about-highlights {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 24px;
}

.highlight {
    font-size: 0.9rem;
    color: var(--text);
    font-weight: 500;
}

.highlight span { color: var(--accent); margin-right: 6px; font-weight: 700; }

.about-card {
    padding: 32px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    text-align: center;
    position: sticky;
    top: calc(var(--nav-height) + 24px);
}

.about-avatar { margin-bottom: 16px; }

.avatar-placeholder {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    font-size: 1.6rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.about-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.about-title {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.about-location {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 16px;
}

.about-contact-links {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.about-contact-links a {
    font-size: 0.88rem;
    color: var(--primary);
    font-weight: 500;
    transition: var(--transition);
}

.about-contact-links a:hover { color: var(--primary-light); }

/* ============================================
   CONTACT FORM
   ============================================ */
.contact {
    padding: 100px 0;
    background: var(--bg);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
    align-items: start;
}

.contact-form {
    background: var(--bg-white);
    padding: 36px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
}

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

.form-row-3 { grid-template-columns: 1fr 1fr 1fr; }

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

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.92rem;
    font-family: inherit;
    color: var(--text);
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-lighter);
    box-shadow: 0 0 0 3px var(--primary-soft);
    background: white;
}

.form-group textarea { resize: vertical; min-height: 100px; }

.btn-submit {
    width: 100%;
    padding: 16px;
    font-size: 1rem;
    font-weight: 600;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    margin-top: 4px;
}

.btn-submit:hover { background: var(--primary-light); }

.form-note {
    text-align: center;
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-top: 12px;
}

/* --- Contact Info Cards --- */
.contact-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-card {
    padding: 28px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.contact-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-light);
}

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

.contact-icon { font-size: 1.15rem; flex-shrink: 0; margin-top: 2px; }

.contact-item strong {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: 2px;
}

.contact-item a,
.contact-item span {
    font-size: 0.92rem;
    color: var(--text);
    font-weight: 500;
}

.contact-item a:hover { color: var(--primary); }

.contact-card p {
    font-size: 0.88rem;
    color: var(--text-light);
    line-height: 1.6;
}

.contact-response {
    margin-top: 12px;
    padding: 10px 14px;
    background: var(--accent-soft);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--accent);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: var(--bg-dark);
    color: var(--text-white);
    padding: 64px 0 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand p {
    font-size: 0.88rem;
    color: #94a3b8;
    line-height: 1.7;
    margin-top: 12px;
    max-width: 280px;
}

.footer-logo {
    font-size: 1.2rem;
    color: white;
}

.footer-logo strong { color: #64b5f6; }

.footer-links h4 {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 16px;
    color: #94a3b8;
}

.footer-links ul { display: flex; flex-direction: column; gap: 8px; }

.footer-links a {
    font-size: 0.9rem;
    color: #cbd5e1;
    transition: var(--transition);
}

.footer-links a:hover { color: white; }

.footer-links li { font-size: 0.9rem; color: #cbd5e1; }

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid #1e293b;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.82rem;
    color: #64748b;
    line-height: 1.8;
}

/* ============================================
   FORM SUCCESS MESSAGE
   ============================================ */
.form-success {
    display: none;
    text-align: center;
    padding: 48px 24px;
}

.form-success.active { display: block; }

.form-success .success-icon { font-size: 3rem; margin-bottom: 16px; }

.form-success h3 { font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; }

.form-success p { color: var(--text-light); }

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: 1fr; gap: 32px; }
    .about-card { position: static; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .form-row-3 { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
        transform: translateY(-120%);
        transition: var(--transition-slow);
        z-index: -1;
    }

    .nav-menu.active { transform: translateY(0); }

    .nav-toggle { display: flex; }

    .hero-stats { gap: 28px; }

    .stat-number { font-size: 1.6rem; }

    .product-grid { grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); }

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

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

    .form-row { grid-template-columns: 1fr; }
    .form-row-3 { grid-template-columns: 1fr; }

    .product-tabs { gap: 6px; }
    .tab-btn { padding: 8px 14px; font-size: 0.78rem; }

    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}

@media (max-width: 480px) {
    .hero-container { padding: 100px 16px 60px; }
    .hero-cta { flex-direction: column; align-items: center; }
    .hero-stats { flex-direction: column; gap: 20px; }
    .section-container { padding: 0 16px; }
    .contact-form { padding: 24px; }
}