:root {
    --primary: #0682b4;
    --primary-dark: #045b80;
    --accent: #31b7e9;
    --dark: #1d2a3b;
    --gray: #6b7280;
    --light: #f4f7fa;
    --border: #e3e8ee;
    --success: #16a34a;
    --danger: #dc2626;
    --radius: 12px;
    --shadow: 0 4px 18px rgba(29, 42, 59, 0.08);
}

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

body {
    font-family: 'Segoe UI', 'Open Sans', system-ui, sans-serif;
    color: var(--dark);
    background: var(--light);
    line-height: 1.6;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; }

.container { max-width: 1140px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
    background: #fff;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.site-header .bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 20px;
    color: var(--dark);
}
.logo .mark {
    width: 34px; height: 34px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 8px;
    display: grid; place-items: center;
    color: #fff; font-weight: 800;
}
.nav { display: flex; align-items: center; gap: 22px; }
.nav a { color: var(--dark); font-weight: 600; }
.nav a:hover { color: var(--primary); text-decoration: none; }

.cart-link {
    position: relative;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--light);
    padding: 8px 14px;
    border-radius: 999px;
    font-weight: 600;
}
.cart-count {
    background: var(--danger);
    color: #fff;
    border-radius: 999px;
    padding: 0 7px;
    font-size: 12px;
    line-height: 18px;
    min-width: 18px;
    text-align: center;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 11px 22px;
    border: none;
    border-radius: 8px;
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    transition: background .2s, transform .05s;
}
.btn:hover { background: var(--primary-dark); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn-block { display: block; width: 100%; text-align: center; }
.btn-outline { background: transparent; color: var(--primary); border: 1px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }
.btn-sm { padding: 7px 14px; font-size: 14px; }
.btn-danger { background: var(--danger); }
.btn-danger:hover { background: #b91c1c; }

/* Hero */
.hero {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    padding: 64px 0;
    text-align: center;
}
.hero h1 { font-size: 38px; margin-bottom: 14px; }
.hero p { font-size: 18px; opacity: .95; margin-bottom: 26px; }

/* Sections */
.section { padding: 50px 0; }
.section-title {
    font-size: 26px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}

/* Toolbar */
.toolbar {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 26px;
}
.toolbar input[type="search"],
.toolbar select {
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    background: #fff;
}
.toolbar input[type="search"] { flex: 1; min-width: 220px; }

/* Product grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 22px;
}
.card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: box-shadow .2s, transform .2s;
}
.card:hover { box-shadow: var(--shadow); transform: translateY(-3px); }
.thumb {
    height: 160px;
    display: grid;
    place-items: center;
    color: #fff;
    font-size: 44px;
    font-weight: 800;
}
.card-body { padding: 18px; flex: 1; display: flex; flex-direction: column; }
.card-body .cat {
    font-size: 12px;
    color: var(--gray);
    text-transform: uppercase;
    letter-spacing: .5px;
    font-weight: 700;
}
.card-body h3 { font-size: 18px; margin: 6px 0 8px; }
.card-body .desc { font-size: 14px; color: var(--gray); flex: 1; }
.price-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 14px 0;
}
.price { font-size: 19px; font-weight: 800; color: var(--primary); }
.license { font-size: 12px; color: var(--gray); }

/* Product detail */
.detail {
    display: grid;
    grid-template-columns: 360px 1fr;
    gap: 36px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 30px;
}
.detail .thumb { height: 320px; border-radius: var(--radius); font-size: 80px; }
.detail .cat { color: var(--gray); text-transform: uppercase; font-weight: 700; font-size: 13px; }
.detail h1 { font-size: 30px; margin: 8px 0 14px; }
.detail .price { font-size: 30px; }
.feature-list { list-style: none; margin: 16px 0; }
.feature-list li {
    padding: 8px 0 8px 28px;
    position: relative;
    border-bottom: 1px dashed var(--border);
}
.feature-list li::before {
    content: "\2713";
    position: absolute;
    left: 0; top: 8px;
    color: var(--success);
    font-weight: 800;
}

/* Cart & checkout */
.cart-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; }
.cart-table th, .cart-table td { padding: 14px 16px; text-align: left; border-bottom: 1px solid var(--border); }
.cart-table th { background: var(--light); font-size: 14px; }
.cart-table td.amount { font-weight: 700; }
.qty-control { display: flex; align-items: center; gap: 8px; }
.qty-control input { width: 56px; padding: 6px; text-align: center; border: 1px solid var(--border); border-radius: 6px; }

.summary {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px;
}
.summary .row {
    display: flex; justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px dashed var(--border);
}
.summary .total { font-size: 20px; font-weight: 800; color: var(--primary); border: none; margin-top: 8px; }

.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
.form-group.full { grid-column: 1 / -1; }
.form-group label { font-weight: 600; font-size: 14px; }
.form-group input, .form-group textarea, .form-group select {
    padding: 11px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus { outline: 2px solid var(--accent); border-color: var(--accent); }
.error { color: var(--danger); font-size: 14px; margin-bottom: 14px; }

/* Two column layout */
.layout { display: grid; grid-template-columns: 1fr 340px; gap: 30px; align-items: start; }

/* Messages */
.notice {
    background: #ecfdf5;
    border: 1px solid #a7f3d0;
    color: #065f46;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 16px;
}

/* Footer */
.site-footer {
    background: var(--dark);
    color: #cbd5e1;
    padding: 34px 0;
    margin-top: 40px;
    font-size: 14px;
}
.site-footer a { color: #93c5fd; }
.footer-grid { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 20px; }
.footer-grid h4 { color: #fff; margin-bottom: 10px; }

/* Admin */
.admin-wrap { max-width: 1000px; margin: 40px auto; }
.login-box { max-width: 380px; margin: 80px auto; background: #fff; padding: 32px; border-radius: var(--radius); box-shadow: var(--shadow); }
.admin-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; }
.admin-table th, .admin-table td { padding: 12px 14px; border-bottom: 1px solid var(--border); text-align: left; font-size: 14px; }
.admin-table th { background: var(--light); }

/* Empty state */
.empty {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray);
    background: #fff;
    border: 1px dashed var(--border);
    border-radius: var(--radius);
}

/* Responsive */
@media (max-width: 860px) {
    .detail, .layout { grid-template-columns: 1fr; }
    .form-grid { grid-template-columns: 1fr; }
    .nav { gap: 14px; }
}
@media (max-width: 560px) {
    .hero h1 { font-size: 28px; }
    .nav .hide-sm { display: none; }
}