.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: triangle-area-calculator --- */
.triangle-calculator {
    max-width: 1200px;
    margin: 0 auto;
}

.method-card {
    transition: all 0.3s ease;
    border: 1px solid #dee2e6;
}

.method-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.method-card.active {
    border-color: #0d6efd;
    background-color: #f8f9ff;
}

.formula-box {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 8px;
    padding: 15px;
    margin: 15px 0;
    border-left: 4px solid #0d6efd;
}

.formula-text {
    font-family: 'Courier New', monospace;
    font-size: 1.1em;
    color: #495057;
    margin: 0;
}

.result-display {
    background: linear-gradient(135deg, #d1ecf1 0%, #bee5eb 100%);
    border-radius: 8px;
    padding: 20px;
    margin-top: 20px;
    border: 1px solid #bee5eb;
}

.step-item {
    background: #f8f9fa;
    border-radius: 6px;
    padding: 10px 15px;
    margin: 8px 0;
    border-left: 3px solid #28a745;
}

.step-number {
    background: #28a745;
    color: white;
    border-radius: 50%;
    width: 24px;
    height: 24px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
    margin-right: 10px;
}

.area-result {
    font-size: 1.5em;
    font-weight: bold;
    color: #0d6efd;
    text-align: center;
    padding: 15px;
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    border-radius: 8px;
    margin: 15px 0;
}

.input-group-custom {
    position: relative;
}

.input-group-custom .form-control {
    padding-right: 40px;
}

.input-group-custom .unit-label {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: #6c757d;
    font-size: 0.9em;
    pointer-events: none;
}

.visual-triangle {
    width: 100px;
    height: 80px;
    margin: 10px auto;
    position: relative;
}

.visual-triangle svg {
    width: 100%;
    height: 100%;
}

.triangle-label {
    position: absolute;
    font-size: 12px;
    font-weight: bold;
    color: #495057;
}

.triangle-label.a { top: 5px; left: 50%; transform: translateX(-50%); }
.triangle-label.b { bottom: 5px; left: 5px; }
.triangle-label.c { bottom: 5px; right: 5px; }
.triangle-label.h { top: 50%; right: 5px; transform: translateY(-50%); }