/* ==========================================================================
   Main Styles — GOS Chemicals
   All styles reference tokens.css variables — no raw hex or font names.
   ========================================================================== */

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 1rem;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-accent); }

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

/* --- Typography --- */
h1, h2, h3, h4 { font-family: var(--font-heading); color: var(--color-primary); line-height: 1.25; }
h1 { font-size: 2.5rem; font-weight: 700; }
h2 { font-size: 1.75rem; font-weight: 600; }
h3 { font-size: 1.25rem; font-weight: 600; }

.section-eyebrow {
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: 0.5rem;
}

/* --- Layout --- */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: var(--spacing-section) 0;
}

.section--alt {
    background: var(--color-surface);
}

/* --- Header / Nav --- */
.site-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.site-logo {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: 0.02em;
    text-decoration: none;
}

.site-logo-img {
    height: 42px;
    width: auto;
    max-width: 44px;
    border-radius: var(--radius-base);
    object-fit: contain;
    display: block;
}

.site-logo-text {
    font-family: var(--font-heading);
    font-weight: 700;
}

.site-logo--footer {
    margin-bottom: 0.75rem;
}

.site-nav { display: flex; align-items: center; gap: 2rem; }
.site-nav a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
    transition: color var(--transition-fast);
    position: relative;
}
.site-nav a:hover,
.site-nav a.active { color: var(--color-primary); }
.site-nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-base);
}
.site-nav a:hover::after,
.site-nav a.active::after { width: 100%; }

.nav-cta {
    background: var(--color-primary) !important;
    color: var(--color-surface) !important;
    padding: 0.5rem 1.25rem;
    border-radius: var(--radius-base);
    font-size: 0.85rem !important;
    font-weight: 500 !important;
    transition: background var(--transition-fast) !important;
}
.nav-cta:hover { background: var(--color-primary-dark) !important; }
.nav-cta::after { display: none !important; }

/* Mobile nav toggle */
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 0.5rem; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); margin: 5px 0; transition: var(--transition-fast); }

/* --- Hero --- */
.hero {
    padding: 5rem 0 4rem;
    text-align: center;
}

.hero h1 { margin-bottom: 1rem; max-width: 700px; margin-left: auto; margin-right: auto; }

.hero-sub {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    margin-bottom: 1rem;
    font-weight: 400;
}

.hero-intro {
    font-size: 1rem;
    color: var(--color-text-muted);
    max-width: 650px;
    margin: 0 auto 2rem;
    line-height: 1.7;
}

.hero-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 0.75rem 1.75rem;
    border-radius: var(--radius-base);
    font-size: 0.9rem;
    font-weight: 500;
    font-family: var(--font-body);
    cursor: pointer;
    border: none;
    transition: background var(--transition-fast), transform var(--transition-fast);
    text-decoration: none;
}
.btn:hover { transform: translateY(-1px); }

.btn-primary {
    background: var(--color-primary);
    color: var(--color-surface);
}
.btn-primary:hover { background: var(--color-primary-dark); color: var(--color-surface); }

.btn-accent {
    background: var(--color-accent);
    color: var(--color-surface);
}
.btn-accent:hover { background: var(--color-accent-hover); color: var(--color-surface); }

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
}
.btn-outline:hover { background: var(--color-primary); color: var(--color-surface); }

/* --- Cards --- */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    padding: 2rem;
    transition: box-shadow var(--transition-base), transform var(--transition-base);
}
.card:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

.card h3 { margin-bottom: 0.75rem; }
.card p { color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.6; }

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.card-link { display: block; text-decoration: none; color: inherit; }
.card-link:hover { color: inherit; }

/* --- Product Detail --- */
.product-detail { padding: var(--spacing-section) 0; }

.product-detail h1 { margin-bottom: 1.5rem; }

.product-meta {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.product-meta-item h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--color-accent);
}

.product-meta-item p,
.product-meta-item ul { color: var(--color-text-muted); font-size: 0.95rem; }

.product-meta-item ul { list-style: none; padding: 0; }
.product-meta-item ul li { padding: 0.25rem 0; padding-left: 1rem; position: relative; }
.product-meta-item ul li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-size: 0.85rem;
}

.product-image {
    width: 100%;
    max-width: 500px;
    border-radius: var(--radius-base);
    border: 1px solid var(--color-border);
}

/* --- Why Source Section --- */
.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

.why-item { padding: 1.5rem; }
.why-item h3 { font-size: 1rem; margin-bottom: 0.5rem; }
.why-item p { color: var(--color-text-muted); font-size: 0.9rem; }

/* --- FAQ Accordion --- */
.faq-list { max-width: 800px; margin: 0 auto; }

.faq-item {
    border-bottom: 1px solid var(--color-border);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    padding: 1.25rem 0;
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: color var(--transition-fast);
}
.faq-question:hover { color: var(--color-primary); }

.faq-question .faq-icon {
    font-size: 1.25rem;
    transition: transform var(--transition-base);
    color: var(--color-accent);
    flex-shrink: 0;
    margin-left: 1rem;
}

.faq-item.open .faq-icon { transform: rotate(45deg); }

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    color: var(--color-text-muted);
    font-size: 0.95rem;
    line-height: 1.7;
}

.faq-item.open .faq-answer {
    max-height: 500px;
    padding-bottom: 1.25rem;
}

/* --- Contact Form --- */
.contact-form {
    max-width: 700px;
    margin: 0 auto;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group { margin-bottom: 1rem; }
.form-group.full-width { grid-column: 1 / -1; }

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--color-text-muted);
    margin-bottom: 0.3rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    font-family: var(--font-body);
    font-size: 0.9rem;
    background: var(--color-surface);
    color: var(--color-text);
    transition: border-color var(--transition-fast);
}

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

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

.form-status {
    padding: 1rem;
    border-radius: var(--radius-base);
    margin-top: 1rem;
    font-size: 0.9rem;
    display: none;
}
.form-status.success { display: block; background: #eafaf1; color: #27ae60; border: 1px solid #a3dfbf; }
.form-status.error { display: block; background: #fdedec; color: #c0392b; border: 1px solid #f5b7b1; }

/* --- Custom Manufacturing --- */
.custom-categories {
    list-style: none;
    padding: 0;
    columns: 2;
    column-gap: 2rem;
}

.custom-categories li {
    padding: 0.6rem 0;
    padding-left: 1.25rem;
    position: relative;
    font-size: 0.95rem;
    color: var(--color-text);
    break-inside: avoid;
}

.custom-categories li::before {
    content: '●';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-size: 0.6rem;
    top: 0.85rem;
}

/* --- Industries Grid --- */
.industries-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
}

.industry-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    padding: 1.5rem;
    transition: border-color var(--transition-base);
}
.industry-card:hover { border-color: var(--color-accent); }
.industry-card h3 { font-size: 1rem; margin-bottom: 0.4rem; }
.industry-card p { color: var(--color-text-muted); font-size: 0.9rem; }

/* --- Footer --- */
.site-footer {
    background: var(--color-primary);
    color: rgba(255,255,255,0.7);
    padding: 3rem 0 2rem;
    font-size: 0.875rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: start;
    gap: 2rem;
    flex-wrap: wrap;
}

.footer-brand { max-width: 350px; }
.footer-brand .site-logo { color: var(--color-surface); font-size: 1.1rem; margin-bottom: 0.5rem; display: block; }
.footer-brand p { line-height: 1.6; }

.footer-links h4 { color: var(--color-surface); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 0.75rem; }
.footer-links a { display: block; color: rgba(255,255,255,0.6); padding: 0.2rem 0; font-size: 0.85rem; }
.footer-links a:hover { color: var(--color-surface); }

.footer-contact p { margin-bottom: 0.3rem; }

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-top: 2rem;
    padding-top: 1.5rem;
    text-align: center;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.4);
}

/* --- Loading & Empty States --- */
.loading-state, .empty-state, .error-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--color-text-muted);
}

.loading-spinner {
    width: 28px;
    height: 28px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
    margin: 0 auto 1rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* --- Section Titles --- */
.section-title { text-align: center; margin-bottom: 3rem; }
.section-title h2 { margin-bottom: 0.5rem; }
.section-title p { color: var(--color-text-muted); max-width: 550px; margin: 0 auto; }

/* --- Page Header (for inner pages) --- */
.page-header {
    padding: 3rem 0;
    text-align: center;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-surface);
}
.page-header h1 { font-size: 2rem; margin-bottom: 0.5rem; }
.page-header p { color: var(--color-text-muted); }

/* --- Not Found --- */
.not-found { text-align: center; padding: 5rem 1rem; }
.not-found h2 { margin-bottom: 1rem; }
.not-found p { color: var(--color-text-muted); margin-bottom: 2rem; }

/* --- Responsive --- */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    .section { padding: calc(var(--spacing-section) * 0.6) 0; }

    .site-nav { display: none; position: absolute; top: 72px; left: 0; right: 0; background: var(--color-surface); flex-direction: column; padding: 1rem; border-bottom: 1px solid var(--color-border); gap: 0.5rem; }
    .site-nav.open { display: flex; }
    .site-nav a { padding: 0.5rem 0; }
    .nav-toggle { display: block; }

    .product-meta { grid-template-columns: 1fr; }
    .form-grid { grid-template-columns: 1fr; }
    .footer-content { flex-direction: column; }
    .custom-categories { columns: 1; }
}