/* Diophantine Equation Solver - Number Theory / Algebra */
:root {
    --tool-primary: #7c3aed;
    --tool-primary-dark: #6d28d9;
    --tool-gradient: linear-gradient(135deg, #7c3aed 0%, #a78bfa 100%);
    --tool-light: #f5f3ff;
}

[data-theme="dark"] {
    --tool-light: rgba(124, 58, 237, 0.15);
}

/* ===== Mode Toggle ===== */
.dio-mode-toggle {
    display: flex;
    flex-wrap: wrap;
    gap: 0.375rem;
    margin-bottom: 1rem;
}

.dio-mode-btn {
    flex: 1 1 auto;
    min-width: 0;
    padding: 0.5rem 0.75rem;
    font-weight: 600;
    font-size: 0.8125rem;
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-full, 9999px);
    cursor: pointer;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    transition: all 0.2s ease;
    text-align: center;
    white-space: nowrap;
}

.dio-mode-btn.active {
    background: var(--tool-gradient);
    color: #fff;
    border-color: var(--tool-primary);
    box-shadow: 0 2px 8px rgba(124, 58, 237, 0.25);
}

.dio-mode-btn:hover:not(.active) {
    background: var(--tool-light);
    border-color: var(--tool-primary);
    color: var(--tool-primary);
}

/* ===== Preview ===== */
.dio-preview {
    background: var(--tool-light);
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-md, 0.5rem);
    padding: 0.75rem 1rem;
    margin: 0.75rem 0;
    text-align: center;
    min-height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: auto;
}

.dio-preview .katex-display {
    margin: 0;
}

/* ===== Action Row ===== */
.dio-action-row {
    display: flex;
    gap: 0.5rem;
    margin: 0.75rem 0;
}

.dio-compute-btn {
    flex: 1;
    background: var(--tool-gradient) !important;
    border-color: var(--tool-primary) !important;
}

.dio-compute-btn:hover {
    box-shadow: 0 4px 12px rgba(124, 58, 237, 0.3);
}

.dio-compute-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.dio-random-btn {
    padding: 0.5rem 0.875rem;
    font-size: 0.8125rem;
    font-weight: 600;
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-md, 0.5rem);
    cursor: pointer;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    transition: all 0.15s;
    white-space: nowrap;
}

.dio-random-btn:hover {
    border-color: var(--tool-primary);
    color: var(--tool-primary);
    background: var(--tool-light);
}

/* ===== Export Row ===== */
.dio-export-row {
    display: flex;
    gap: 0.375rem;
    margin: 0.5rem 0;
    flex-wrap: wrap;
}

.dio-export-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.35rem 0.625rem;
    font-size: 0.75rem;
    font-weight: 600;
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-sm, 0.375rem);
    cursor: pointer;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    transition: all 0.15s;
}

.dio-export-btn:hover {
    border-color: var(--tool-primary);
    color: var(--tool-primary);
    background: var(--tool-light);
}

/* ===== Separator ===== */
.dio-sep {
    border: none;
    border-top: 1px solid var(--border-light, #f1f5f9);
    margin: 0.75rem 0;
}

/* ===== Examples ===== */
.dio-examples {
    display: flex;
    flex-wrap: wrap;
    gap: 0.375rem;
}

.dio-example-chip {
    padding: 0.3rem 0.625rem;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--border, #e2e8f0);
    border-radius: 9999px;
    cursor: pointer;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    transition: all 0.15s;
}

.dio-example-chip:hover {
    border-color: var(--tool-primary);
    color: var(--tool-primary);
    background: var(--tool-light);
}

/* ===== Formulas Toggle ===== */
.dio-formulas-toggle,
.dio-syntax-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.625rem 0;
    cursor: pointer;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-secondary, #64748b);
    border-bottom: 1px solid var(--border-light, #f1f5f9);
}

.dio-formulas-toggle:hover,
.dio-syntax-toggle:hover {
    color: var(--tool-primary);
}

.dio-formulas-content,
.dio-syntax-content {
    animation: dio-fadeIn 0.2s ease;
}

.dio-formulas-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8125rem;
    margin: 0.5rem 0;
}

.dio-formulas-table th {
    text-align: left;
    padding: 0.4rem 0.5rem;
    font-weight: 600;
    color: var(--text-secondary, #64748b);
    border-bottom: 1.5px solid var(--border, #e2e8f0);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.dio-formulas-table td {
    padding: 0.5rem;
    border-bottom: 1px solid var(--border-light, #f1f5f9);
    color: var(--text-primary);
    vertical-align: middle;
}

/* ===== Output Tabs ===== */
.dio-output-tabs {
    display: flex;
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-md, 0.5rem);
    overflow: hidden;
    margin-bottom: 0.75rem;
}

.dio-output-tab {
    flex: 1;
    padding: 0.5rem 0.25rem;
    font-weight: 600;
    font-size: 0.8125rem;
    border: none;
    cursor: pointer;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    transition: all 0.2s;
    text-align: center;
}

.dio-output-tab.active {
    background: var(--tool-gradient);
    color: #fff;
}

.dio-output-tab:hover:not(.active) {
    background: var(--tool-light);
    color: var(--tool-primary);
}

/* ===== Panels ===== */
.dio-panel {
    display: none;
    flex: 1;
    min-height: 0;
}

.dio-panel.active {
    display: flex;
    flex-direction: column;
    animation: dio-fadeIn 0.2s ease;
}

@keyframes dio-fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Form Wraps Animation ===== */
#dio-linear-wrap,
#dio-system-wrap,
#dio-quadratic-wrap,
#dio-modular-wrap {
    animation: dio-fadeIn 0.2s ease;
}

/* ===== Empty State ===== */
.dio-empty-icon {
    font-size: 2rem;
    font-weight: 700;
    color: var(--tool-primary);
    opacity: 0.3;
    margin-bottom: 0.75rem;
    font-family: 'JetBrains Mono', monospace;
}

/* ===== Result Badges ===== */
.dio-meta-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.375rem;
    margin-bottom: 0.75rem;
}

.dio-method-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    background: var(--tool-light);
    color: var(--tool-primary);
    padding: 0.2rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.6875rem;
    font-weight: 600;
}

.dio-verified-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    background: #dcfce7;
    color: #16a34a;
    padding: 0.2rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.6875rem;
    font-weight: 600;
}

[data-theme="dark"] .dio-verified-badge {
    background: rgba(22, 163, 74, 0.15);
}

.dio-classify-badge {
    display: inline-flex;
    align-items: center;
    background: var(--bg-secondary, #f8fafc);
    color: var(--text-secondary, #64748b);
    padding: 0.2rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.6875rem;
    font-weight: 600;
    border: 1px solid var(--border-light, #f1f5f9);
}

.dio-nosolution-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
    background: #fef2f2;
    color: #dc2626;
    padding: 0.2rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.6875rem;
    font-weight: 600;
}

[data-theme="dark"] .dio-nosolution-badge {
    background: rgba(220, 38, 38, 0.15);
}

/* ===== Result Math ===== */
.dio-result-math {
    background: var(--bg-secondary, #f8fafc);
    border: 1.5px solid var(--border, #e2e8f0);
    border-radius: var(--radius-md, 0.5rem);
    padding: 1rem;
    margin-bottom: 1rem;
}

.dio-result-label {
    font-size: 0.625rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--tool-primary);
    margin-bottom: 0.5rem;
}

.dio-result-main {
    font-size: 1.125rem;
    overflow-x: auto;
    padding: 0.25rem 0;
}

.dio-result-main .katex-display {
    margin: 0;
}

/* ===== Steps ===== */
.dio-steps {
    margin-top: 0.5rem;
}

.dio-steps-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-secondary, #64748b);
    margin-bottom: 0.5rem;
}

.dio-step {
    display: flex;
    gap: 0.75rem;
    padding: 0.875rem 1rem;
    border-bottom: 1px solid var(--border-light, #f1f5f9);
    align-items: flex-start;
}

.dio-step:last-child {
    border-bottom: none;
}

.dio-step-num {
    flex: 0 0 auto;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--tool-gradient);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.6875rem;
    font-weight: 700;
}

.dio-step-body {
    flex: 1;
    min-width: 0;
}

.dio-step-title {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.dio-step-math {
    overflow-x: auto;
    font-size: 1rem;
    padding: 0.25rem 0;
}

.dio-step-math .katex-display {
    margin: 0;
    overflow-x: auto;
    display: inline-block;
    min-width: min-content;
}

/* ===== Error ===== */
.dio-error {
    background: #fef2f2;
    border: 1.5px solid #fecaca;
    border-radius: var(--radius-md, 0.5rem);
    padding: 1rem;
    color: #991b1b;
}

[data-theme="dark"] .dio-error {
    background: rgba(220, 38, 38, 0.1);
    border-color: rgba(220, 38, 38, 0.3);
    color: #fca5a5;
}

.dio-error h4 {
    margin: 0 0 0.25rem;
    font-size: 0.875rem;
}

.dio-error p {
    margin: 0;
    font-size: 0.8125rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .dio-mode-btn {
        padding: 0.4rem 0.5rem;
        font-size: 0.75rem;
    }
}

@media (max-width: 600px) {
    .dio-mode-btn {
        flex: 0 0 calc(50% - 0.25rem);
    }

    .dio-output-tab {
        font-size: 0.75rem;
        padding: 0.4rem 0.25rem;
    }

    .dio-step {
        padding: 0.625rem 0.5rem;
        gap: 0.5rem;
    }

    .dio-step-math {
        font-size: 0.875rem;
    }
}