/* PO REA Phase I design system — mobile first, frameworkless CSS */
:root {
    --color-ink: #101828;
    --color-navy: #14213d;
    --color-navy-2: #1f2f52;
    --color-yellow: #f7c948;
    --color-yellow-strong: #e6a900;
    --color-yellow-soft: #fff6cf;
    --color-surface: #ffffff;
    --color-surface-muted: #f8fafc;
    --color-border: #d9e0ea;
    --color-muted: #667085;
    --color-success: #166534;
    --color-success-bg: #ecfdf3;
    --color-warning: #92400e;
    --color-warning-bg: #fffbeb;
    --color-danger: #b42318;
    --color-danger-bg: #fef3f2;
    --color-info: #175cd3;
    --color-info-bg: #eff8ff;

    --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --radius-sm: .5rem;
    --radius-md: .75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --shadow-sm: 0 1px 2px rgba(16, 24, 40, .06);
    --shadow-md: 0 10px 28px rgba(20, 33, 61, .10);
    --container: 1180px;
    --transition: 160ms ease;
}

*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light; scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: var(--font-sans);
    color: var(--color-ink);
    background: linear-gradient(180deg, var(--color-yellow-soft) 0, #fffdf4 19rem, var(--color-surface-muted) 34rem);
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}
img, svg, video { max-width: 100%; height: auto; }
button, input, select, textarea { font: inherit; }
a { color: inherit; }
button { cursor: pointer; }

:focus-visible {
    outline: 3px solid rgba(23, 92, 211, .35);
    outline-offset: 2px;
}

.skip-link {
    position: fixed;
    left: 1rem;
    top: .75rem;
    z-index: 999;
    padding: .65rem .9rem;
    border-radius: var(--radius-sm);
    background: var(--color-navy);
    color: #fff;
    transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }

.container {
    width: min(100% - 2rem, var(--container));
    margin-inline: auto;
}

.section { padding: 2.25rem 0; }
.section-title { margin: 0 0 .4rem; font-size: clamp(1.45rem, 4vw, 2rem); color: var(--color-navy); }
.section-copy { margin: 0; color: var(--color-muted); max-width: 62ch; }
.stack { display: grid; gap: 1rem; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: .75rem; }
.grid { display: grid; gap: 1rem; }
.grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    border-bottom: 1px solid rgba(20, 33, 61, .12);
    background: rgba(255, 255, 255, .94);
    backdrop-filter: blur(12px);
}
.header-inner {
    min-height: 4.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}
.brand {
    display: inline-flex;
    align-items: center;
    gap: .65rem;
    text-decoration: none;
    font-weight: 800;
    color: var(--color-navy);
    letter-spacing: -.02em;
}
.brand-mark {
    display: grid;
    place-items: center;
    width: 2.25rem;
    height: 2.25rem;
    border-radius: .8rem;
    background: var(--color-yellow);
    color: var(--color-navy);
    box-shadow: inset 0 0 0 1px rgba(20, 33, 61, .12);
    font-size: .82rem;
}
.nav-toggle {
    border: 1px solid var(--color-border);
    background: #fff;
    color: var(--color-navy);
    border-radius: var(--radius-sm);
    padding: .58rem .75rem;
    font-weight: 700;
}
.primary-nav {
    display: none;
    position: absolute;
    inset: 4.25rem 1rem auto 1rem;
    padding: .75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: #fff;
    box-shadow: var(--shadow-md);
}
.primary-nav.is-open { display: grid; gap: .35rem; }
.primary-nav a {
    display: block;
    padding: .72rem .8rem;
    text-decoration: none;
    border-radius: var(--radius-sm);
    color: var(--color-navy);
    font-weight: 650;
}
.primary-nav a:hover, .primary-nav a[aria-current="page"] { background: var(--color-yellow-soft); }
.header-actions { display: none; }

.hero { padding: 3rem 0 2rem; }
.hero-panel {
    overflow: hidden;
    position: relative;
    border: 1px solid rgba(20, 33, 61, .12);
    border-radius: var(--radius-xl);
    background: linear-gradient(135deg, #fff9dc 0%, #fff 58%, #f4f7fb 100%);
    box-shadow: var(--shadow-md);
    padding: clamp(1.5rem, 5vw, 3.25rem);
}
.hero-panel::after {
    content: "";
    position: absolute;
    width: 12rem;
    height: 12rem;
    border-radius: 50%;
    right: -4rem;
    top: -4rem;
    background: rgba(247, 201, 72, .35);
}
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: .45rem;
    margin-bottom: .8rem;
    color: var(--color-navy);
    font-size: .86rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: .08em;
}
.hero h1 {
    position: relative;
    z-index: 1;
    margin: 0;
    max-width: 15ch;
    color: var(--color-navy);
    font-size: clamp(2rem, 8vw, 4rem);
    line-height: 1.03;
    letter-spacing: -.045em;
}
.hero p { max-width: 62ch; margin: 1rem 0 0; color: #475467; }
.hero-actions { margin-top: 1.35rem; display: flex; flex-wrap: wrap; gap: .75rem; }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .45rem;
    min-height: 2.75rem;
    padding: .68rem 1rem;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 760;
    transition: transform var(--transition), background var(--transition), border-color var(--transition);
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--color-navy); color: #fff; }
.btn-primary:hover { background: var(--color-navy-2); }
.btn-accent { background: var(--color-yellow); color: var(--color-navy); border-color: rgba(20, 33, 61, .12); }
.btn-accent:hover { background: #f3bc2d; }
.btn-secondary { background: #fff; color: var(--color-navy); border-color: var(--color-border); }
.btn-danger { background: var(--color-danger); color: #fff; }
.btn-sm { min-height: 2.25rem; padding: .45rem .75rem; font-size: .9rem; }
.btn-block { width: 100%; }

.card {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}
.card-body { padding: 1rem; }
.card-title { margin: 0; color: var(--color-navy); font-size: 1.05rem; }
.card-copy { margin: .4rem 0 0; color: var(--color-muted); }
.card-footer { padding: .85rem 1rem; border-top: 1px solid var(--color-border); background: #fbfcfe; }

.listing-card-media {
    aspect-ratio: 4 / 3;
    background: linear-gradient(135deg, #f4f6fa, #e9edf4);
    display: grid;
    place-items: center;
    color: #98a2b3;
    font-weight: 700;
}
.price { color: var(--color-navy); font-weight: 850; font-size: 1.08rem; }
.meta { color: var(--color-muted); font-size: .9rem; }

.chip {
    display: inline-flex;
    align-items: center;
    gap: .35rem;
    min-height: 2.2rem;
    padding: .45rem .72rem;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    background: #fff;
    text-decoration: none;
    color: var(--color-navy);
    font-weight: 700;
    font-size: .9rem;
}
.chip:hover { border-color: var(--color-yellow-strong); background: var(--color-yellow-soft); }

.form-group { display: grid; gap: .4rem; }
.label { font-weight: 720; color: var(--color-navy); }
.hint, .field-error { margin: 0; font-size: .86rem; }
.hint { color: var(--color-muted); }
.field-error { color: var(--color-danger); }
.input, .select, .textarea {
    width: 100%;
    border: 1px solid #cfd7e3;
    border-radius: var(--radius-md);
    background: #fff;
    color: var(--color-ink);
    padding: .72rem .8rem;
    min-height: 2.8rem;
    transition: border-color var(--transition), box-shadow var(--transition);
}
.textarea { min-height: 8rem; resize: vertical; }
.input:focus, .select:focus, .textarea:focus {
    border-color: #7aa7ee;
    box-shadow: 0 0 0 3px rgba(23, 92, 211, .12);
    outline: 0;
}
.input[aria-invalid="true"], .select[aria-invalid="true"], .textarea[aria-invalid="true"] { border-color: var(--color-danger); }

.alert {
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    padding: .8rem .9rem;
    font-size: .94rem;
}
.alert-success { background: var(--color-success-bg); color: var(--color-success); border-color: #abefc6; }
.alert-warning { background: var(--color-warning-bg); color: var(--color-warning); border-color: #fedf89; }
.alert-danger { background: var(--color-danger-bg); color: var(--color-danger); border-color: #fecdca; }
.alert-info { background: var(--color-info-bg); color: var(--color-info); border-color: #b2ddff; }

.state {
    min-height: 12rem;
    display: grid;
    place-items: center;
    text-align: center;
    padding: 1.5rem;
    border: 1px dashed #c7d0dd;
    border-radius: var(--radius-lg);
    background: rgba(255,255,255,.78);
}
.state h3 { margin: 0; color: var(--color-navy); }
.state p { margin: .4rem 0 0; color: var(--color-muted); max-width: 46ch; }
.skeleton {
    min-height: 1rem;
    border-radius: .45rem;
    background: linear-gradient(90deg, #eef1f5 25%, #f8fafc 50%, #eef1f5 75%);
    background-size: 200% 100%;
    animation: shimmer 1.35s linear infinite;
}
@keyframes shimmer { to { background-position: -200% 0; } }

.site-footer {
    margin-top: 3rem;
    border-top: 1px solid rgba(20, 33, 61, .12);
    background: var(--color-navy);
    color: #dbe3ef;
}
.footer-inner { padding: 2rem 0; display: grid; gap: 1rem; }
.footer-inner a { color: #fff; }

/* Authenticated / seller / admin shell */
.app-shell { min-height: 100vh; background: var(--color-surface-muted); }
.app-topbar {
    position: sticky;
    top: 0;
    z-index: 40;
    border-bottom: 1px solid var(--color-border);
    background: #fff;
}
.app-topbar-inner { min-height: 4rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.app-body { display: grid; min-height: calc(100vh - 4rem); }
.app-sidebar {
    display: none;
    border-right: 1px solid var(--color-border);
    background: #fff;
    padding: 1rem;
}
.app-sidebar nav { display: grid; gap: .35rem; }
.app-sidebar a { padding: .65rem .75rem; border-radius: var(--radius-sm); text-decoration: none; color: var(--color-navy); font-weight: 650; }
.app-sidebar a:hover, .app-sidebar a[aria-current="page"] { background: var(--color-yellow-soft); }
.app-content { min-width: 0; padding: 1rem 0 2rem; }
.page-header { display: flex; flex-direction: column; gap: .75rem; margin-bottom: 1rem; }
.page-title { margin: 0; color: var(--color-navy); font-size: clamp(1.45rem, 4vw, 2rem); }

.sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

@media (min-width: 640px) {
    .container { width: min(100% - 3rem, var(--container)); }
    .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .hero { padding-top: 4rem; }
    .card-body { padding: 1.15rem; }
    .page-header { flex-direction: row; align-items: center; justify-content: space-between; }
}

@media (min-width: 768px) {
    .nav-toggle { display: none; }
    .primary-nav {
        position: static;
        display: flex;
        align-items: center;
        gap: .2rem;
        padding: 0;
        border: 0;
        border-radius: 0;
        background: transparent;
        box-shadow: none;
    }
    .primary-nav a { padding: .55rem .65rem; }
    .header-actions { display: flex; align-items: center; gap: .5rem; }
    .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .footer-inner { grid-template-columns: 1.4fr 1fr; align-items: end; }
    .app-body { grid-template-columns: 15rem minmax(0, 1fr); }
    .app-sidebar { display: block; }
    .app-content { padding: 1.5rem 0 3rem; }
}

@media (min-width: 1024px) {
    .section { padding: 3rem 0; }
    .grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .hero-panel { padding: 3.5rem; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}