:root {
    --demo-bg: #0a0b0d;
    --demo-panel: #15181c;
    --demo-panel-strong: #1b2026;
    --demo-border: #2b333d;
    --demo-accent: #76d6ff;
    --demo-accent-strong: #b9efff;
    --demo-text: #f5f7fa;
    --demo-text-muted: #b4bcc7;
    --demo-danger: #ff8f6b;
    --demo-shadow: rgba(0, 0, 0, 0.28);
    --demo-code: #0a0c10;
}

html, body {
    margin: 0;
    min-height: 100%;
    background:
        radial-gradient(circle at top left, rgba(118, 214, 255, 0.08), transparent 32%),
        linear-gradient(160deg, #07080a 0%, #0e1014 52%, #111419 100%);
    color: var(--demo-text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body {
    min-height: 100vh;
}

.demo-shell {
    width: min(1180px, calc(100vw - 32px));
    margin: 0 auto;
    padding: 36px 0 48px;
}

.demo-hero,
.demo-panel {
    background: rgba(32, 37, 34, 0.9);
    border: 1px solid var(--demo-border);
    box-shadow: 0 18px 40px var(--demo-shadow);
    backdrop-filter: blur(10px);
}

.demo-hero {
    padding: 32px;
    margin-bottom: 20px;
}

.demo-eyebrow {
    margin: 0 0 14px;
    color: var(--demo-accent);
    font-size: 12px;
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.demo-hero-copy h1 {
    margin: 0;
    font-size: clamp(2rem, 4vw, 3.4rem);
    line-height: 0.96;
    letter-spacing: -0.04em;
}

.demo-subtitle {
    max-width: 800px;
    margin: 18px 0 0;
    color: var(--demo-text-muted);
    font-size: 1rem;
    line-height: 1.6;
}

.demo-hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 24px;
}

.demo-button {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 18px;
    border: 1px solid var(--demo-border);
    text-decoration: none;
    color: var(--demo-text);
    font-weight: 600;
    transition: transform 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
    background: transparent;
    cursor: pointer;
}

.demo-button:hover,
.demo-button:focus-visible {
    transform: translateY(-1px);
    border-color: var(--demo-accent);
    outline: none;
}

.demo-button-primary {
    background: var(--demo-accent);
    border-color: var(--demo-accent);
    color: #1f241c;
}

.demo-button-primary:hover,
.demo-button-primary:focus-visible {
    border-color: var(--demo-accent-strong);
    background: var(--demo-accent-strong);
}

.demo-button[disabled] {
    opacity: 0.65;
    cursor: progress;
    transform: none;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.demo-grid-bottom {
    align-items: start;
}

.demo-panel {
    padding: 22px;
}

.demo-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 18px;
}

.demo-panel-header h2 {
    margin: 0;
    font-size: 1rem;
    letter-spacing: 0.02em;
}

.demo-badge {
    border: 1px solid var(--demo-border);
    color: var(--demo-text-muted);
    padding: 5px 9px;
    font-size: 0.72rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.demo-badge-success {
    border-color: rgba(118, 214, 255, 0.6);
    color: var(--demo-accent);
}

.demo-badge-danger {
    border-color: rgba(255, 143, 107, 0.55);
    color: var(--demo-danger);
}

.demo-badge-muted {
    opacity: 0.85;
}

.demo-list {
    margin: 0;
    padding-left: 18px;
    color: var(--demo-text-muted);
    line-height: 1.7;
}

.demo-meta {
    display: grid;
    gap: 14px;
    margin: 0;
}

.demo-meta dt {
    margin-bottom: 4px;
    color: var(--demo-text-muted);
    font-size: 0.78rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.demo-meta dd {
    margin: 0;
    font-size: 0.98rem;
}

.demo-message {
    margin-top: 18px;
    padding: 14px 16px;
    border-left: 3px solid var(--demo-border);
    background: rgba(10, 12, 16, 0.72);
    color: var(--demo-text-muted);
    line-height: 1.5;
}

.demo-message-success {
    border-left-color: var(--demo-accent);
    color: var(--demo-text);
}

.demo-message-error {
    border-left-color: var(--demo-danger);
    color: #ffd5cb;
}

.receipt-list,
.catalog-list {
    display: grid;
    gap: 12px;
}

.receipt-card,
.catalog-card {
    border: 1px solid var(--demo-border);
    background: rgba(10, 12, 16, 0.76);
    padding: 16px;
}

.receipt-card-header,
.catalog-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 10px;
}

.receipt-card h3,
.catalog-card h3 {
    margin: 0;
    font-size: 0.95rem;
}

.receipt-summary,
.catalog-meta {
    margin: 0;
    color: var(--demo-text-muted);
    font-size: 0.92rem;
    line-height: 1.6;
}

.receipt-details {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 14px;
    margin-top: 12px;
}

.receipt-detail {
    border-top: 1px solid rgba(43, 51, 61, 0.65);
    padding-top: 10px;
}

.receipt-detail-label {
    display: block;
    color: var(--demo-text-muted);
    font-size: 0.72rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 4px;
}

.receipt-detail-value {
    font-size: 0.92rem;
    word-break: break-word;
}

.demo-code {
    margin: 0;
    padding: 16px;
    min-height: 420px;
    max-height: 620px;
    overflow: auto;
    border: 1px solid var(--demo-border);
    background: var(--demo-code);
    color: #d8e2ec;
    font-size: 0.85rem;
    line-height: 1.55;
    white-space: pre-wrap;
}

.demo-inline-link {
    color: var(--demo-accent);
    text-decoration: none;
    font-size: 0.92rem;
}

.demo-inline-link.disabled {
    color: var(--demo-text-muted);
    pointer-events: none;
}

.receipt-empty {
    padding: 18px;
    border: 1px dashed rgba(43, 51, 61, 0.8);
    color: var(--demo-text-muted);
    background: rgba(10, 12, 16, 0.45);
}

code {
    color: var(--demo-accent);
    font-size: 0.95em;
}

@media (max-width: 900px) {
    .demo-grid {
        grid-template-columns: 1fr;
    }

    .receipt-details {
        grid-template-columns: 1fr;
    }

    .demo-shell {
        width: min(100vw - 20px, 1180px);
        padding-top: 20px;
    }

    .demo-hero,
    .demo-panel {
        padding: 18px;
    }
}