.tool-fullwidth {
    width: 100%;
    max-width: 100%;
    margin: 0;
    padding: 0;
}

/* Tool shell */
.engineering-tool {
    max-width: 100%;
    margin: 0 auto;
}

.engineering-tool.editor-section,
.editor-section.engineering-tool {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.engineering-tool .card:not(.result-card) {
    border: 1px solid var(--color-border, #e5e7eb);
    box-shadow: var(--shadow-sm, 0 1px 3px rgba(0, 0, 0, 0.06));
    border-radius: var(--radius, 12px);
    background: var(--color-surface, #fff);
}

.engineering-tool .card-body {
    padding: 1.25rem 1.35rem;
}

.engineering-tool .card-title {
    color: var(--color-text, #1f2937);
    font-weight: 700;
    font-size: 1.05rem;
}

.engineering-tool .form-control,
.engineering-tool .form-select,
.engineering-tool .select-input,
.engineering-tool textarea {
    border-radius: 8px;
    border: 1px solid var(--color-border, #e5e7eb);
}

.engineering-tool .form-control:focus,
.engineering-tool .form-select:focus,
.engineering-tool textarea:focus {
    border-color: var(--color-primary, #0d9488);
    box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

.engineering-tool .btn-primary {
    background: var(--color-primary, #0d9488);
    border-color: var(--color-primary, #0d9488);
}

.engineering-tool .btn-primary:hover {
    background: var(--color-primary-hover, #0f766e);
    border-color: var(--color-primary-hover, #0f766e);
}

.engineering-tool .alert {
    border-radius: 10px;
}

[data-theme="dark"] .engineering-tool .card:not(.result-card) {
    background: var(--color-surface, #1f2937);
    border-color: var(--color-border, #374151);
}

[data-theme="dark"] .engineering-tool .card-title,
[data-theme="dark"] .engineering-tool .form-label,
[data-theme="dark"] .engineering-tool {
    color: var(--color-text, #f9fafb);
}

[data-theme="dark"] .engineering-tool .text-muted,
[data-theme="dark"] .engineering-tool .form-text {
    color: var(--color-text-secondary, #9ca3af) !important;
}

[data-theme="dark"] .engineering-tool .form-control,
[data-theme="dark"] .engineering-tool .form-select,
[data-theme="dark"] .engineering-tool textarea {
    background: #111827;
    color: var(--color-text, #f9fafb);
    border-color: var(--color-border, #374151);
}

/* --- tool: scale-calculator --- */
.scale-calculator {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.scale-calculator .card {
    border: none;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border-radius: 12px;
}

.scale-calculator .card-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 12px 12px 0 0 !important;
    border: none;
}

.scale-calculator .calc-type-btn {
    border-radius: 8px;
    transition: all 0.3s ease;
    border: 2px solid #e9ecef;
}

.scale-calculator .calc-type-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.scale-calculator .calc-type-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-color: #667eea;
}

.scale-calculator .calculator-section {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.scale-calculator .calculator-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.scale-calculator .form-control {
    border-radius: 8px;
    border: 2px solid #e9ecef;
    transition: all 0.3s ease;
}

.scale-calculator .form-control:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

.scale-calculator .btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
    transition: all 0.3s ease;
}

.scale-calculator .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.scale-calculator .result-box {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 8px;
    padding: 20px;
    border-left: 4px solid #667eea;
}

.scale-calculator .alert {
    border-radius: 8px;
    border: none;
}

.scale-calculator .scale-visual {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 8px;
    padding: 20px;
    color: white;
    text-align: center;
}

.scale-calculator .scale-bar {
    height: 8px;
    background: rgba(255,255,255,0.3);
    border-radius: 4px;
    margin: 10px 0;
    position: relative;
}

.scale-calculator .scale-markers {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 0.9em;
}

.scale-calculator .preset-scales {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 10px;
    margin-top: 15px;
}

.scale-calculator .preset-btn {
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    color: white;
    border-radius: 6px;
    padding: 8px 12px;
    font-size: 0.9em;
    transition: all 0.3s ease;
}

.scale-calculator .preset-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-1px);
}

.scale-calculator .unit-converter {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    margin-top: 15px;
}

.scale-calculator .history-item {
    background: white;
    border-radius: 6px;
    padding: 10px;
    margin: 5px 0;
    border-left: 3px solid #667eea;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.scale-calculator .formula-display {
    background: #e3f2fd;
    border-radius: 8px;
    padding: 15px;
    margin: 15px 0;
    border-left: 4px solid #2196f3;
}

.scale-calculator .formula-display code {
    background: rgba(33, 150, 243, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    color: #1976d2;
}