/* IPv4 Subnet Calculator */

.ipv4SubnetCalculator-container {
    max-width: var(--app-container-max);
    margin: 0 auto;
}

.subnet-calculator {
    margin-top: var(--space-6);
}

.subnet-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-6);
}

.subnet-card,
.faq-section {
    background: var(--color-bg-card);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--space-5);
}

.subnet-card-header {
    margin-bottom: var(--space-5);
}

.subnet-card-header h2,
.faq-section h2 {
    margin: 0 0 var(--space-2);
    font-size: var(--font-size-2xl);
    line-height: var(--line-height-tight);
}

.subnet-card-header p,
.subnet-field-help,
.subnet-empty,
.subnet-status {
    color: var(--color-text-muted);
    line-height: var(--line-height-normal);
}

.subnet-card-header p,
.subnet-field-help,
.subnet-empty,
.subnet-status,
.subnet-error {
    margin: 0;
}

.subnet-field-grid {
    display: grid;
    gap: var(--space-4);
}

.subnet-field {
    display: grid;
    gap: var(--space-2);
}

.subnet-field label {
    font-weight: 600;
}

.subnet-input {
    width: 100%;
    min-height: var(--favorites-bar-height);
    padding: var(--space-3) var(--space-4);
    color: var(--color-text);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font: inherit;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.subnet-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: var(--focus-ring);
}

.subnet-input[aria-invalid="true"] {
    border-color: var(--color-error);
}

.subnet-actions,
.subnet-output-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    margin-top: var(--space-5);
}

.subnet-output-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-4);
}

.subnet-output-actions {
    margin-top: 0;
}

.subnet-results {
    display: grid;
    gap: var(--space-3);
    margin: 0;
}

.subnet-results[hidden],
.subnet-empty[hidden] {
    display: none;
}

.subnet-result-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-1);
    padding: var(--space-3);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.subnet-result-row dt {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    font-weight: 600;
}

.subnet-result-row dd {
    margin: 0;
    overflow-wrap: anywhere;
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-normal);
}

.subnet-empty {
    padding: var(--space-5);
    text-align: center;
    background: var(--color-bg-alt);
    border: 1px dashed var(--color-border);
    border-radius: var(--radius-md);
}

.subnet-error {
    margin-top: var(--space-4);
    color: var(--color-error-text);
    font-weight: 600;
    line-height: var(--line-height-normal);
}

.subnet-status {
    min-height: var(--space-6);
    margin-top: var(--space-4);
}

.btn[disabled] {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
}

.faq-section {
    margin-top: var(--space-8);
}

.faq-list {
    display: grid;
    gap: var(--space-4);
}

.faq-item {
    padding: var(--space-4);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.faq-item h3 {
    margin: 0 0 var(--space-2);
    font-size: var(--font-size-lg);
    line-height: var(--line-height-tight);
}

.faq-item p {
    margin: 0;
    color: var(--color-text-muted);
    line-height: var(--line-height-normal);
}

.help-section + .help-section {
    margin-top: var(--space-5);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--favorites-bar-height);
    height: var(--favorites-bar-height);
    color: var(--color-text-muted);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    font-size: var(--font-size-lg);
    font-weight: 600;
    transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}

.btn-icon:hover {
    color: var(--color-text);
    background: var(--color-border);
}

.btn-icon:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.btn-icon:active {
    transform: scale(0.98);
}

@media (min-width: 768px) {
    .subnet-grid {
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        align-items: start;
    }

    .subnet-result-row {
        grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
        align-items: center;
    }
}

@media (max-width: 768px) {
    .subnet-card,
    .faq-section {
        padding: var(--space-4);
    }

    .subnet-output-header,
    .subnet-actions,
    .subnet-output-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .subnet-actions .btn,
    .subnet-output-actions .btn {
        width: 100%;
    }
}