/* Periodic Table Store — Light Grayscale Theme */

:root {
    --pt-white: #ffffff;
    --pt-bg: #f8f9fa;
    --pt-surface: #ffffff;
    --pt-card: #ffffff;
    --pt-border: #e2e5e9;
    --pt-border-hover: #c8ccd0;
    --pt-text: #1a1a1a;
    --pt-text-secondary: #4a4a4a;
    --pt-text-muted: #6e7681;
    --pt-accent: #111111;
    --pt-accent-hover: #333333;
    --pt-blue: #4a6fa5;
    --pt-purple: #7c6ea5;
    --pt-orange: #b87333;
    --pt-red: #a05252;
    --pt-green: #528060;
}

/* Reset & Base */
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: var(--pt-bg);
    color: var(--pt-text-secondary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

main { flex: 1; }

a { color: var(--pt-text); font-weight: 500; }
a:hover { color: var(--pt-accent); }

/* Top Alert Banner */
.top-banner {
    background: #1a1a1a;
    color: #ccc;
    padding: 0.55rem 0;
    font-size: 0.85rem;
    text-align: center;
}
.top-banner a {
    color: #fff;
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 2px;
}
.top-banner a:hover { color: #fff; opacity: 0.85; }
.top-banner .btn-close {
    filter: invert(1);
    opacity: 0.45;
    font-size: 0.6rem;
    padding: 0.5rem;
}

/* Navbar */
.navbar {
    background: var(--pt-white) !important;
    border-bottom: 1px solid var(--pt-border);
    padding: 0.75rem 0;
}
.navbar-brand {
    font-weight: 700;
    color: var(--pt-text) !important;
    font-size: 1.1rem;
    letter-spacing: -0.02em;
}
.navbar-brand span { color: var(--pt-text-muted); }
.navbar .nav-link {
    color: var(--pt-text-muted) !important;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.5rem 0.85rem !important;
    transition: color 0.15s;
}
.navbar .nav-link:hover,
.navbar .nav-link.active { color: var(--pt-text) !important; }
.navbar-toggler { border-color: var(--pt-border); }

/* Cart badge */
.cart-link { position: relative; }
.cart-link .badge {
    font-size: 0.6rem;
    padding: 0.2em 0.45em;
    position: absolute;
    top: 2px;
    right: -4px;
    background: var(--pt-text) !important;
}

/* Dropdown */
.dropdown-menu {
    max-height: 300px;
    overflow-y: auto;
    background: var(--pt-white);
    border-color: var(--pt-border);
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}
.dropdown-item { color: var(--pt-text-secondary); font-size: 0.85rem; }
.dropdown-item:hover { background: var(--pt-bg); color: var(--pt-text); }

/* Hero Section */
.hero {
    padding: 5rem 0 4rem;
    text-align: center;
    background: var(--pt-white);
    border-bottom: 1px solid var(--pt-border);
}
.hero h1 {
    font-size: 3.2rem;
    font-weight: 800;
    color: var(--pt-text);
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 1.25rem;
}
.hero h1 .accent { color: var(--pt-text-muted); }
.hero .lead {
    font-size: 1.15rem;
    color: var(--pt-text-muted);
    max-width: 520px;
    margin: 0 auto 2rem;
    line-height: 1.6;
}

/* Buttons */
.btn-accent {
    background: var(--pt-text);
    color: var(--pt-white);
    font-weight: 600;
    border: none;
    padding: 0.65rem 1.8rem;
    border-radius: 8px;
    transition: all 0.15s;
}
.btn-accent:hover {
    background: var(--pt-accent-hover);
    color: var(--pt-white);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.btn-accent-outline {
    background: transparent;
    color: var(--pt-text);
    font-weight: 600;
    border: 2px solid var(--pt-text);
    padding: 0.6rem 1.8rem;
    border-radius: 8px;
    transition: all 0.15s;
}
.btn-accent-outline:hover {
    background: var(--pt-text);
    color: var(--pt-white);
}
.btn-ghost {
    background: transparent;
    color: var(--pt-text-secondary);
    border: 1px solid var(--pt-border);
    font-weight: 500;
    padding: 0.65rem 1.8rem;
    border-radius: 8px;
    transition: all 0.15s;
}
.btn-ghost:hover {
    background: var(--pt-bg);
    color: var(--pt-text);
    border-color: var(--pt-border-hover);
}

/* Cards */
.product-card {
    background: var(--pt-card);
    border: 1px solid var(--pt-border);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.2s;
}
.product-card:hover {
    border-color: var(--pt-border-hover);
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
}
.product-card .card-body { padding: 1.25rem; }
.product-card .card-title {
    color: var(--pt-text);
    font-weight: 600;
    font-size: 1rem;
}
.product-card .card-text { color: var(--pt-text-muted); font-size: 0.85rem; }
.product-card .price { color: var(--pt-text); font-weight: 700; font-size: 1.35rem; }
.product-card .compare-price {
    color: var(--pt-text-muted);
    text-decoration: line-through;
    font-size: 0.9rem;
}

.product-placeholder {
    height: 220px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f0f1f3;
    font-size: 3.5rem;
    border-bottom: 1px solid var(--pt-border);
    color: #c0c4c8;
}

/* Category badges */
.cat-badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}
.cat-poster { background: #e8edf4; color: var(--pt-blue); }
.cat-framed { background: #edeaf4; color: var(--pt-purple); }
.cat-canvas { background: #f4ede4; color: var(--pt-orange); }
.cat-tshirt { background: #f4e8e8; color: var(--pt-red); }
.cat-digital { background: #e8f0ea; color: var(--pt-green); }

/* Category filter pills */
.filter-pills {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}
.filter-pill {
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    text-decoration: none;
    border: 1px solid var(--pt-border);
    color: var(--pt-text-muted);
    background: var(--pt-white);
    transition: all 0.15s;
}
.filter-pill:hover { color: var(--pt-text); border-color: var(--pt-border-hover); }
.filter-pill.active {
    background: var(--pt-text);
    color: var(--pt-white);
    border-color: var(--pt-text);
}

/* Feature grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}
.feature-item {
    background: var(--pt-white);
    border: 1px solid var(--pt-border);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    transition: all 0.15s;
}
.feature-item:hover {
    border-color: var(--pt-border-hover);
    box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}
.feature-icon { font-size: 2rem; margin-bottom: 0.75rem; }
.feature-item h3 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--pt-text);
    margin-bottom: 0.4rem;
}
.feature-item p {
    color: var(--pt-text-muted);
    font-size: 0.8rem;
    margin: 0;
    line-height: 1.5;
}

/* Stats bar */
.stats-bar {
    background: var(--pt-white);
    border: 1px solid var(--pt-border);
    border-radius: 12px;
    padding: 2rem;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
}
.stat-item strong {
    display: block;
    font-size: 1.5rem;
    color: var(--pt-text);
    font-weight: 700;
}
.stat-item span {
    font-size: 0.8rem;
    color: var(--pt-text-muted);
}

/* Section headers */
.section-header {
    text-align: center;
    margin-bottom: 2.5rem;
}
.section-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--pt-text);
    margin-bottom: 0.5rem;
}
.section-header p {
    color: var(--pt-text-muted);
    max-width: 500px;
    margin: 0 auto;
}

/* CTA Section */
.cta-section {
    background: var(--pt-white);
    border: 1px solid var(--pt-border);
    border-radius: 16px;
    padding: 3rem;
    text-align: center;
}
.cta-section h2 { color: var(--pt-text); font-weight: 700; }
.cta-section p { color: var(--pt-text-muted); }

/* Cart page */
.cart-table { color: var(--pt-text-secondary); }
.cart-table th {
    color: var(--pt-text-muted);
    font-weight: 500;
    font-size: 0.85rem;
    border-bottom-color: var(--pt-border);
}
.cart-table td {
    border-bottom-color: var(--pt-border);
    vertical-align: middle;
}
.cart-summary {
    background: var(--pt-white);
    border: 1px solid var(--pt-border);
    border-radius: 12px;
    padding: 1.5rem;
}

/* Product detail */
.product-detail-img {
    background: #f0f1f3;
    border-radius: 12px;
    border: 1px solid var(--pt-border);
    height: 450px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    color: #c0c4c8;
}
.detail-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.detail-list li {
    padding: 0.4rem 0;
    color: var(--pt-text-muted);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.detail-list li::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--pt-text-muted);
    border-radius: 50%;
    flex-shrink: 0;
}

/* Footer */
footer {
    background: var(--pt-white);
    border-top: 1px solid var(--pt-border);
    padding: 2.5rem 0;
}
footer a {
    color: var(--pt-text-muted);
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.15s;
}
footer a:hover { color: var(--pt-text); }
.footer-brand {
    color: var(--pt-text);
    font-weight: 700;
    font-size: 1rem;
}
.footer-brand span { color: var(--pt-text-muted); }

/* Content pages */
.content-page {
    max-width: 700px;
    margin: 0 auto;
    padding: 2rem 1rem;
}
.content-page h1 {
    color: var(--pt-text);
    font-weight: 700;
    margin-bottom: 1.5rem;
    text-align: center;
}
.content-page h3 {
    color: var(--pt-text);
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: 2rem;
    margin-bottom: 0.75rem;
}
.content-page p, .content-page li {
    color: var(--pt-text-secondary);
    line-height: 1.7;
}

/* Form cards */
.form-card {
    background: var(--pt-white);
    border: 1px solid var(--pt-border);
    border-radius: 12px;
    padding: 2rem;
}
.form-card .form-control {
    background: var(--pt-bg);
    border-color: var(--pt-border);
    color: var(--pt-text);
}
.form-card .form-control:focus {
    background: var(--pt-white);
    border-color: var(--pt-text-muted);
    box-shadow: 0 0 0 0.2rem rgba(0,0,0,0.06);
    color: var(--pt-text);
}
.form-card .form-label { color: var(--pt-text-secondary); font-size: 0.85rem; font-weight: 500; }

/* 404 */
.page-404 {
    text-align: center;
    padding: 5rem 1rem;
}
.page-404 .element-card {
    display: inline-block;
    background: var(--pt-white);
    border: 2px solid var(--pt-text);
    border-radius: 8px;
    padding: 1.5rem 2rem;
    margin-bottom: 1.5rem;
}
.page-404 .atomic-num { font-size: 0.8rem; color: var(--pt-text-muted); }
.page-404 .symbol { font-size: 3rem; font-weight: 800; color: var(--pt-text); line-height: 1; }
.page-404 .el-name { font-size: 0.85rem; color: var(--pt-text-muted); }

/* Order complete */
.order-success-icon {
    width: 70px;
    height: 70px;
    background: #e8f0ea;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 2rem;
    color: var(--pt-green);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.2rem; }
    .hero .lead { font-size: 1rem; }
    .stats-bar { grid-template-columns: repeat(2, 1fr); }
    .product-detail-img { height: 280px; font-size: 4rem; }
}