/* ═══════════════════════════════════════════════════════════════
   StairMaster — The Code-Compliant Stair Stringer Calculator
   Bespoke theme: Construction yellow/amber on dark charcoal
   ═══════════════════════════════════════════════════════════════ */

:root {
    --bg-primary: #141210;
    --bg-surface: #1e1c18;
    --bg-hover: #2a2720;
    --bg-input: #252218;
    --text-primary: #f5f0e8;
    --text-secondary: #c4bba8;
    --text-muted: #8a8170;
    --accent: #f59e0b;
    --accent-hover: #d97706;
    --accent-glow: rgba(245, 158, 11, 0.15);
    --accent-glow-strong: rgba(245, 158, 11, 0.3);
    --border: rgba(196, 187, 168, 0.12);
    --border-hover: rgba(245, 158, 11, 0.4);
    --success: #22c55e;
    --success-bg: rgba(34, 197, 94, 0.12);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.12);
    --error: #ef4444;
    --error-bg: rgba(239, 68, 68, 0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
    --transition: 0.2s ease;
}

/* ── Light Mode ───────────────────────────────── */
[data-theme="light"] {
    --bg-primary: #faf8f5;
    --bg-surface: #ffffff;
    --bg-hover: #f0ece4;
    --bg-input: #f5f2ec;
    --text-primary: #1a1814;
    --text-secondary: #4a4538;
    --text-muted: #7a7468;
    --border: rgba(26, 24, 20, 0.1);
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-secondary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ── Header ───────────────────────────────────── */
.site-header {
    background: linear-gradient(135deg, #1a1710 0%, #141210 100%);
    border-bottom: 1px solid var(--border);
    padding: 2rem 0 1.5rem;
    text-align: center;
}

.header-inner { display: flex; flex-direction: column; align-items: center; gap: 0.25rem; }

.brand { display: flex; align-items: center; gap: 0.75rem; }
.brand-icon { font-size: 2rem; }
.brand-name {
    font-family: 'Outfit', sans-serif;
    font-weight: 800;
    font-size: clamp(1.8rem, 5vw, 2.5rem);
    color: var(--text-primary);
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.brand-tagline {
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    color: var(--accent);
    letter-spacing: 0.02em;
    margin-top: 0.25rem;
}

.brand-subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
    max-width: 500px;
    margin-top: 0.25rem;
}

/* ── Privacy Badge ────────────────────────────── */
.privacy-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--accent-glow);
    border: 1px solid rgba(245, 158, 11, 0.2);
    border-radius: 999px;
    padding: 0.4rem 1rem;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    margin: 1.5rem auto 1rem;
    text-align: center;
    width: fit-content;
}

.badge-icon { font-size: 0.9rem; }

/* ── App Grid ─────────────────────────────────── */
.app-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-top: 1rem;
}

@media (min-width: 768px) {
    .app-grid { grid-template-columns: 400px 1fr; }
}

/* ── Panels ───────────────────────────────────── */
.panel {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.panel-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.35rem;
    color: var(--text-primary);
    margin-bottom: 1.25rem;
    letter-spacing: -0.01em;
}

/* ── Input Groups ─────────────────────────────── */
.input-group { margin-bottom: 1.25rem; }
.input-group--half { flex: 1; min-width: 0; }

.input-row {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.4rem;
}

input[type="number"],
select {
    width: 100%;
    padding: 0.65rem 0.85rem;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    transition: border-color var(--transition), box-shadow var(--transition);
    appearance: none;
    -webkit-appearance: none;
}

select {
    font-family: 'Inter', sans-serif;
    font-size: 0.85rem;
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238a8170' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2rem;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-hint {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.3rem;
}

/* ── Preset Buttons ───────────────────────────── */
.preset-row {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.4rem;
    flex-wrap: wrap;
}

.btn-preset {
    padding: 0.4rem 0.9rem;
    font-size: 0.8rem;
    font-weight: 600;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition);
    font-family: 'JetBrains Mono', monospace;
}

.btn-preset:hover {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
}

.btn-preset.active {
    background: var(--accent-glow-strong);
    border-color: var(--accent);
    color: var(--accent);
}

/* ── Buttons ──────────────────────────────────── */
.btn-calculate {
    width: 100%;
    padding: 0.85rem;
    font-size: 1rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    border: none;
    border-radius: var(--radius-sm);
    color: #1a1200;
    cursor: pointer;
    transition: all var(--transition);
    font-family: 'Inter', sans-serif;
    letter-spacing: 0.01em;
    margin-top: 0.5rem;
}

.btn-calculate:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(245, 158, 11, 0.35);
}

.btn-calculate:active { transform: translateY(0); }

/* ── Error Message ────────────────────────────── */
.error-message {
    background: var(--error-bg);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    font-size: 0.85rem;
    color: var(--error);
    margin-bottom: 1rem;
}

.hidden { display: none !important; }

/* ── Code Compliance Banner ───────────────────── */
.code-banner {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1.1rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1.25rem;
    font-weight: 600;
    font-size: 0.9rem;
}

.code-banner--pass {
    background: var(--success-bg);
    border: 1px solid rgba(34, 197, 94, 0.3);
    color: var(--success);
}

.code-banner--fail {
    background: var(--error-bg);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--error);
}

.code-banner--warn {
    background: var(--warning-bg);
    border: 1px solid rgba(245, 158, 11, 0.3);
    color: var(--warning);
}

.code-banner__icon { font-size: 1.2rem; }

/* ── Summary Grid ─────────────────────────────── */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

@media (min-width: 600px) {
    .summary-grid { grid-template-columns: repeat(4, 1fr); }
}

.summary-card {
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.85rem 0.75rem;
    text-align: center;
    transition: border-color var(--transition);
}

.summary-card:hover { border-color: var(--border-hover); }

.summary-card--highlight {
    border-color: var(--accent);
    background: var(--accent-glow);
}

.summary-label {
    display: block;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    margin-bottom: 0.35rem;
}

.summary-value {
    display: block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* ── Compliance Grid ──────────────────────────── */
.compliance-checks {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.5rem;
}

@media (min-width: 480px) {
    .compliance-checks { grid-template-columns: 1fr 1fr; }
}

.compliance-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.65rem 0.85rem;
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    font-weight: 500;
}

.compliance-item--pass {
    background: var(--success-bg);
    border: 1px solid rgba(34, 197, 94, 0.2);
    color: var(--success);
}

.compliance-item--fail {
    background: var(--error-bg);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: var(--error);
}

.compliance-icon { font-size: 1rem; }

/* ── Export Row ────────────────────────────────── */
.export-row {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
    flex-wrap: wrap;
}

.btn-export {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    font-weight: 600;
    background: var(--bg-hover);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition);
}

.btn-export:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-glow);
}

.export-icon { font-size: 0.9rem; }

/* ── Stringer Diagram ─────────────────────────── */
.section-subtitle {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.diagram-heading { margin-top: 0.5rem; }

.stringer-diagram {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1rem;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: auto;
}

.stringer-diagram svg {
    width: 100%;
    height: auto;
    max-height: 400px;
}

.diagram-placeholder {
    color: var(--text-muted);
    font-size: 0.9rem;
    text-align: center;
}

.diagram-placeholder strong { color: var(--accent); }

/* ── Material List ────────────────────────────── */
.material-table-wrap { overflow-x: auto; }

.material-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.material-table th {
    text-align: left;
    padding: 0.6rem 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.material-table td {
    padding: 0.6rem 0.75rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
}

.material-table td:last-child {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 500;
    color: var(--accent);
}

/* ── How It Works ─────────────────────────────── */
.how-it-works {
    margin-top: 2.5rem;
    padding: 2rem 0;
}

.how-title { text-align: center; margin-bottom: 1.5rem; }

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

@media (min-width: 600px) {
    .how-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 900px) {
    .how-grid { grid-template-columns: repeat(4, 1fr); }
}

.how-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    text-align: center;
    transition: border-color var(--transition), transform var(--transition);
}

.how-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.how-icon { font-size: 1.8rem; display: block; margin-bottom: 0.75rem; }

.how-card-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.how-card p {
    font-size: 0.82rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* ── SEO Content ──────────────────────────────── */
.seo-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-top: 1.5rem;
}

.seo-card h2 {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.seo-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.seo-card strong { color: var(--text-primary); }

/* ── Footer ───────────────────────────────────── */
.site-footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 2rem;
    border-top: 1px solid var(--border);
}

.footer-privacy {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 0.4rem;
}

.footer-disclaimer {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
}

.footer-copyright {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.footer-copyright strong { color: var(--text-secondary); }

/* ── Toast ────────────────────────────────────── */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-surface);
    border: 1px solid var(--accent);
    border-radius: var(--radius-sm);
    padding: 0.7rem 1.4rem;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
    pointer-events: none;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ── Ad Placeholders ──────────────────────────── */
.ad-slot {
    text-align: center;
    padding: 0.5rem;
    border: 1px dashed var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: 0.7rem;
    margin: 1rem auto;
}

.ad-slot--desktop { max-width: 728px; height: 90px; display: none; }
.ad-slot--mobile { max-width: 320px; height: 50px; }

@media (min-width: 768px) {
    .ad-slot--desktop { display: flex; align-items: center; justify-content: center; }
    .ad-slot--mobile { display: none; }
}

/* ── Responsive ───────────────────────────────── */
@media (max-width: 480px) {
    .input-row { flex-direction: column; gap: 0; }
    .summary-grid { grid-template-columns: repeat(2, 1fr); }
}