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

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

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

.academic-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);
}

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

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

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

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

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

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

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

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

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

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

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

/* --- tool: cube-surface-area-calculator --- */
/* 立方体表面积计算器样式 */
.cube-calculator {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.cube-visual {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto;
    perspective: 1000px;
}

.cube-container {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    animation: rotateCube 10s infinite linear;
}

.cube-face {
    position: absolute;
    width: 100px;
    height: 100px;
    border: 2px solid #007bff;
    background: rgba(0, 123, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: #007bff;
}

.cube-face.front {
    transform: translateZ(50px);
}

.cube-face.back {
    transform: translateZ(-50px) rotateY(180deg);
}

.cube-face.right {
    transform: rotateY(90deg) translateZ(50px);
}

.cube-face.left {
    transform: rotateY(-90deg) translateZ(50px);
}

.cube-face.top {
    transform: rotateX(90deg) translateZ(50px);
}

.cube-face.bottom {
    transform: rotateX(-90deg) translateZ(50px);
}

@keyframes rotateCube {
    0% { transform: rotateX(0deg) rotateY(0deg); }
    100% { transform: rotateX(360deg) rotateY(360deg); }
}

.cube-label {
    position: absolute;
    bottom: -40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    font-weight: bold;
    color: #333;
}

.result-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 15px;
    padding: 30px;
    margin: 20px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.result-value {
    font-size: 3rem;
    font-weight: bold;
    margin: 10px 0;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.formula-display {
    background: rgba(255,255,255,0.1);
    padding: 15px;
    border-radius: 10px;
    margin-top: 20px;
    font-family: 'Courier New', monospace;
    font-size: 1.2rem;
}

.calculation-steps {
    font-size: 0.9rem;
    opacity: 0.9;
    margin-top: 10px;
}

.tools-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 15px;
    padding: 25px;
    margin-top: 30px;
}

.tool-btn {
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    color: white;
    padding: 10px 20px;
    margin: 5px;
    border-radius: 25px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.tool-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.input-group-text {
    background: #f8f9fa;
    border-color: #ced4da;
}

.form-control:focus {
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.btn-primary {
    background: linear-gradient(135deg, #007bff, #0056b3);
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-weight: bold;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 123, 255, 0.4);
}

.btn-outline-secondary {
    border-radius: 25px;
    padding: 12px 30px;
    font-weight: bold;
    transition: all 0.3s ease;
}

.btn-outline-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(108, 117, 125, 0.4);
}

.card {
    border: none;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    overflow: hidden;
}

.card-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 25px;
}

.card-body {
    padding: 30px;
}

.form-label {
    font-weight: bold;
    color: #333;
    margin-bottom: 8px;
}

.form-text {
    color: #6c757d;
    font-size: 0.875rem;
}

.alert {
    border-radius: 10px;
    border: none;
}

@media (max-width: 768px) {
    .cube-visual {
        width: 150px;
        height: 150px;
    }
    
    .cube-face {
        width: 75px;
        height: 75px;
    }
    
    .result-value {
        font-size: 2rem;
    }
    
    .tool-btn {
        display: block;
        width: 100%;
        margin: 5px 0;
    }
}