:root {
    --bg-primary: #0b0f19;
    --bg-surface: #131b2e;
    --bg-hover: #1c2842;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent: #38bdf8;
    --accent-glow: rgba(56, 189, 248, 0.15);
    --metal-gold: #f59e0b;
    --border: #23324d;
    --border-light: #2e4166;
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-body);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

.app-header {
    text-align: center;
    padding: 2.5rem 1rem 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.header-badge {
    display: inline-block;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid rgba(56, 189, 248, 0.3);
    border-radius: 20px;
    padding: 0.25rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.app-header h1 {
    font-family: var(--font-heading);
    font-size: 2.75rem;
    font-weight: 800;
    margin: 0 0 0.5rem;
    background: linear-gradient(135deg, #f1f5f9 0%, #38bdf8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

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

.app-main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem 3rem;
}

/* Calculator Main Grid Layout */
.calculator-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

@media (min-width: 900px) {
    .calculator-container {
        grid-template-columns: 460px 1fr;
    }
}

.calculator-card {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

.card-header h2 {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-primary);
}

/* Unit Toggle Buttons */
.unit-toggle {
    display: flex;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 3px;
}

.unit-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.35rem 0.75rem;
    font-size: 0.825rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.unit-btn.active {
    background: var(--accent);
    color: #0b0f19;
}

/* Form Groups */
.bend-form {
    display: flex;
    flex-direction: column;
    gap: 1.15rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.label-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

.unit-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.form-control {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.65rem 0.85rem;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 1rem;
    width: 100%;
    box-sizing: border-box;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

select.form-control {
    font-family: var(--font-body);
    cursor: pointer;
}

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

.form-row.split-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* Quick Thickness Chips */
.quick-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
    margin-top: 0.35rem;
}

.chip {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.chip:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}

.chip.active {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
    font-weight: 600;
}

/* Range Input with Numeric Input */
.range-with-input {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.form-range {
    flex: 1;
    accent-color: var(--accent);
    cursor: pointer;
}

.range-val {
    width: 80px;
    text-align: center;
}

/* Canvas Display Section */
.canvas-container {
    background: #070a12;
    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;
    margin-bottom: 0.75rem;
}

.canvas-header h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-primary);
}

.canvas-badge {
    background: rgba(34, 197, 94, 0.15);
    color: var(--success);
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    text-transform: uppercase;
}

#bendCanvas {
    width: 100%;
    height: auto;
    max-height: 320px;
    display: block;
    border-radius: 8px;
    background: #050810;
}

.canvas-legend {
    display: flex;
    justify-content: center;
    gap: 1.25rem;
    margin-top: 0.75rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

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

.color-box {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 3px;
}

.box-metal {
    background: #38bdf8;
}

.box-neutral {
    background: #f59e0b;
}

.box-dimension {
    background: #94a3b8;
}

/* Results Tiles */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}

.result-tile {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.result-tile:hover {
    border-color: var(--border-light);
}

.result-tile.highlight-tile {
    grid-column: 1 / -1;
    background: linear-gradient(135deg, rgba(56, 189, 248, 0.1) 0%, rgba(245, 158, 11, 0.1) 100%);
    border: 1.5px solid var(--accent);
    padding: 1.25rem;
}

.tile-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: 0.35rem;
}

.highlight-tile .tile-label {
    color: var(--accent);

}

.tile-value {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.highlight-tile .tile-value {
    font-size: 2.2rem;
    color: #ffffff;
}

.tile-subtext {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
    font-family: var(--font-mono);
}

/* Content Documentation Section */
.content-section {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
    margin-top: 2rem;
}

.content-section h2 {
    font-family: var(--font-heading);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 1.5rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
}

.content-section h2:first-of-type {
    margin-top: 0;
}

.content-section p {
    color: var(--text-secondary);
    font-size: 0.975rem;
    margin-bottom: 1.25rem;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin: 1.5rem 0;
}

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

.info-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
}

.info-card h3 {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    color: var(--accent);
    margin-top: 0;
    margin-bottom: 0.75rem;
}

.formula-box {
    background: #050810;
    border: 1px solid var(--border);
    border-left: 3px solid var(--metal-gold);
    padding: 0.75rem;
    border-radius: 6px;
    font-family: var(--font-mono);
    color: var(--metal-gold);
    text-align: center;
    margin: 0.75rem 0;
    overflow-x: auto;
}

.table-responsive {
    overflow-x: auto;
    margin: 1.5rem 0;
}

.spec-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    text-align: left;
}

.spec-table th, .spec-table td {
    padding: 0.85rem 1rem;
    border-bottom: 1px solid var(--border);
}

.spec-table th {
    background: var(--bg-primary);
    color: var(--accent);
    font-family: var(--font-heading);
    font-weight: 700;
}

.spec-table td code {
    font-family: var(--font-mono);
    color: var(--metal-gold);
    background: rgba(245, 158, 11, 0.1);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
}

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

@media (min-width: 768px) {
    .forming-methods {
        grid-template-columns: repeat(3, 1fr);
    }
}

.method-item {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1rem;
}

.method-item h4 {
    font-family: var(--font-heading);
    color: var(--text-primary);
    margin-top: 0;
    margin-bottom: 0.5rem;
}

.method-item p {
    font-size: 0.875rem;
    margin: 0;
}