.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: gallon-liter-conversion-calculator --- */
.gallon-liter-converter {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.result-box {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border: 1px solid #dee2e6;
    border-radius: 8px;
    padding: 20px;
    margin-top: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.input-display, .result-display {
    font-size: 1.2em;
    font-weight: 600;
    color: #495057;
    padding: 10px;
    background: white;
    border-radius: 4px;
    border: 1px solid #ced4da;
    margin-top: 5px;
}

.conversion-info {
    background: #e3f2fd;
    border-left: 4px solid #2196f3;
    padding: 15px;
    border-radius: 4px;
    font-size: 0.9em;
    color: #1565c0;
}

.table th {
    background-color: #343a40;
    color: white;
    font-weight: 600;
}

.card {
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card-header {
    background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
    color: white;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
    border: none;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #0056b3 0%, #004085 100%);
    transform: translateY(-1px);
}

.form-control:focus, .form-select:focus {
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
}

.nav-tabs .nav-link {
    border: none;
    color: #6c757d;
    font-weight: 500;
    transition: all 0.3s ease;
}

.nav-tabs .nav-link.active {
    color: #007bff;
    background: none;
    border-bottom: 2px solid #007bff;
}

.nav-tabs .nav-link:hover {
    border-color: transparent;
    color: #007bff;
}

.alert-danger {
    background-color: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
}

@media (max-width: 768px) {
    .gallon-liter-converter {
        padding: 10px;
    }
    
    .result-box {
        padding: 15px;
    }
    
    .input-display, .result-display {
        font-size: 1.1em;
    }
}