/* ══════════════════════════════════════════════════════════════════
   StitchPredictor — Saddle Stitch Thread Calculator Theme Styles
   Domain: Leathercraft & Hand Stitching
   Palette: Saddle Tan, Roasted Walnut, Aged Cognac & Linen Gold
   ══════════════════════════════════════════════════════════════════ */

:root {
    --bg-primary: #140d09;
    --bg-surface: #1f140e;
    --bg-surface-elevated: #281a13;
    --bg-hover: #332118;
    
    --text-primary: #fef3c7;
    --text-secondary: #d97706;
    --text-muted: #a3724c;
    
    --accent: #f59e0b;
    --accent-hover: #fbbf24;
    --accent-glow: rgba(245, 158, 11, 0.18);
    
    --border: #3d2618;
    --border-highlight: #593924;
    
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    
    --needle-a-color: #f59e0b; /* Linen gold */
    --needle-b-color: #38bdf8; /* Signal blue / contrasting stitch */
    --leather-grain-1: #3b2416;
    --leather-grain-2: #2b180d;
}

/* Base resets & typography */
body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

.app-header {
    text-align: center;
    padding: 2.5rem 1rem 1.5rem;
    background: radial-gradient(circle at top, rgba(245, 158, 11, 0.08) 0%, transparent 70%);
}

.header-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    background: var(--accent-glow);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: 9999px;
    margin-bottom: 0.75rem;
}

.app-header h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    margin: 0 0 0.5rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.app-header p {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin: 0;
}

/* Main Layout Grid */
.app-main {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 1rem 3rem;
}

.calc-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

@media (min-width: 960px) {
    .calc-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.calc-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.75rem;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
}

.card-title {
    font-family: 'Outfit', sans-serif;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
    margin: 0 0 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

/* Form controls & inputs */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-row.dual-fields {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

input[type="number"],
select {
    width: 100%;
    box-sizing: border-box;
    padding: 0.75rem 1rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.readonly-input {
    background-color: var(--bg-surface-elevated);
    color: var(--text-secondary);
    border-style: dashed;
}

/* Input with Unit Group */
.input-with-unit {
    display: flex;
    align-items: center;
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.input-with-unit input {
    border: none;
    border-radius: 0;
    flex: 1;
}

.input-with-unit select,
.input-with-unit .unit-label {
    border: none;
    background-color: var(--bg-surface-elevated);
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    padding: 0.75rem 0.75rem;
    border-left: 1px solid var(--border);
    width: auto;
}

/* Preset Grids */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
}

@media (max-width: 480px) {
    .preset-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.preset-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    padding: 0.6rem 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    text-align: center;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.preset-btn .btn-sub {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 400;
    margin-top: 2px;
}

.preset-btn:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-highlight);
}

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

.preset-btn.active .btn-sub {
    color: var(--text-secondary);
}

/* Unit Tabs */
.unit-tabs {
    display: flex;
    background-color: var(--bg-primary);
    padding: 3px;
    border-radius: 8px;
    border: 1px solid var(--border);
    margin-bottom: 0.75rem;
}

.tab-btn {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-muted);
    padding: 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}

.tab-btn.active {
    background-color: var(--bg-surface-elevated);
    color: var(--accent);
}

.hidden {
    display: none !important;
}

/* Radio Mode Toggles */
.input-mode-toggle {
    display: flex;
    gap: 1rem;
    background-color: var(--bg-primary);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
}

.radio-option input[type="radio"] {
    accent-color: var(--accent);
}

/* Canvas Visualizer Card */
.canvas-wrapper {
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.canvas-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.canvas-title {
    font-weight: 600;
    color: var(--text-secondary);
}

.canvas-scale {
    font-family: 'JetBrains Mono', monospace;
}

#stitchCanvas {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
    background-color: #0d0805;
}

.canvas-legend {
    display: flex;
    gap: 1.25rem;
    justify-content: center;
    margin-top: 0.75rem;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.legend-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.legend-dot.needle-a { background-color: var(--needle-a-color); }
.legend-dot.needle-b { background-color: var(--needle-b-color); }
.legend-dot.leather-layer { background-color: #8b5cf6; }

/* Metrics Display */
.metrics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.metric-box {
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
    text-align: center;
}

.metric-box.primary-metric {
    background: radial-gradient(circle at center, rgba(245, 158, 11, 0.12) 0%, var(--bg-surface-elevated) 100%);
    border-color: rgba(245, 158, 11, 0.4);
}

.metric-label {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.metric-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent);
    line-height: 1.1;
    margin-bottom: 0.3rem;
}

.metric-sub {
    font-size: 0.85rem;
    color: var(--text-primary);
}

/* Advisory Cards */
.advisory-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.advisory-card {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1rem;
}

.advisory-icon {
    font-size: 1.5rem;
    line-height: 1;
    background: var(--bg-surface-elevated);
    padding: 0.6rem;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.advisory-content h3 {
    font-size: 0.85rem;
    font-weight: 600;
    margin: 0 0 0.25rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.advisory-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.advisory-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin: 0;
}

/* Educational & Reference Section */
.educational-section {
    margin-top: 2.5rem;
    background-color: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
}

.educational-section h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    color: var(--accent);
    margin-top: 0;
    margin-bottom: 1.5rem;
}

.edu-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

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

.edu-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
}

.edu-card h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.15rem;
    color: var(--text-primary);
    margin-top: 0;
    margin-bottom: 0.75rem;
}

.edu-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1rem;

}

.formula-box {
    background-color: var(--bg-surface-elevated);
    border: 1px solid var(--border-highlight);
    border-left: 3px solid var(--accent);
    padding: 0.75rem 1rem;
    border-radius: 6px;
    margin: 1rem 0;
}

.formula-box code {
    display: block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

.formula-box code:last-child {
    margin-bottom: 0;
}

/* Reference Table */
.table-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
}

.table-card h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.15rem;
    color: var(--text-primary);
    margin-top: 0;
    margin-bottom: 1rem;
}

.table-wrapper {
    overflow-x: auto;
}

.ref-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    text-align: left;
}

.ref-table th,
.ref-table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
}

.ref-table th {
    background-color: var(--bg-surface-elevated);
    color: var(--accent);
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
}

.ref-table tr:hover td {
    background-color: var(--bg-hover);
}

/* Ad Placeholders */
.ad-placeholder {
    background-color: var(--bg-surface);
    border: 2px dashed var(--border);
    color: var(--text-muted);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 1.5rem auto;
    border-radius: 8px;
}

.ad-desktop {
    width: 728px;
    height: 90px;
    display: none;
}

.ad-mobile {
    width: 320px;
    height: 50px;
    display: flex;
}

@media (min-width: 768px) {
    .ad-desktop { display: flex; }
    .ad-mobile { display: none; }
}