:root {
    --uksc-primary-color: #00d4a4;
    --uksc-primary-hover: #00b890;
    --uksc-light-gray: #f4f4f4;
    --uksc-medium-gray: #e0e0e0;
    --uksc-dark-gray: #555;
    --uksc-bg-color: #fff;
    --uksc-success-color: #28a745;
    --uksc-error-color: #dc3545;
    --uksc-border-radius: 8px;
}
.uksc-calculator-wrapper {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background: var(--uksc-bg-color);
    border-radius: var(--uksc-border-radius);
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.07);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--uksc-dark-gray);
    transition: all 0.3s ease-in-out;
}
.uksc-title {
    font-size: 1.8rem;
    font-weight: 300;
    margin-top: 0;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
}
.uksc-salary-input {
    flex-grow: 1;
    min-width: 150px;
    padding: 0.75rem;
    font-size: 1.5rem;
    border: 1px solid var(--uksc-medium-gray);
    border-radius: var(--uksc-border-radius);
    margin-left: 0.5rem;
    transition: border-color 0.2s;
}
.uksc-salary-input:focus {
    outline: none;
    border-color: var(--uksc-primary-color);
}
.uksc-options-row {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 1.5rem 0;
}
.uksc-checkbox-label {
    display: flex;
    align-items: center;
    cursor: pointer;
}
.uksc-checkbox-label input {
    margin-right: 0.5rem;
}
.uksc-tooltip {
    position: relative;
    display: inline-block;
    cursor: help;
    background: #ccc;
    color: #fff;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    text-align: center;
    line-height: 20px;
}
.uksc-tooltip:before {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    width: 220px;
    padding: 10px;
    background: #333;
    color: #fff;
    border-radius: 5px;
    font-size: 0.9rem;
    text-align: left;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.3s;
    z-index: 10;
}
.uksc-tooltip:hover:before {
    visibility: visible;
    opacity: 1;
}
.uksc-pay-period {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}
.uksc-tabs {
    display: flex;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--uksc-medium-gray);
}
.uksc-tab-link {
    padding: 0.75rem 1rem;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--uksc-dark-gray);
    position: relative;
    transition: color 0.3s;
}
.uksc-tab-link:hover {
    color: var(--uksc-primary-color);
}
.uksc-tab-link.active {
    color: var(--uksc-primary-color);
    font-weight: 600;
}
.uksc-tab-link.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--uksc-primary-color);
}
.uksc-tab-content {
    display: none;
    padding: 1.5rem;
    background: var(--uksc-light-gray);
    border: 1px solid var(--uksc-medium-gray);
    border-top: none;
    animation: fadeIn 0.5s;
}
.uksc-tab-content.active {
    display: block;
}
.uksc-tab-content p {
    margin-top: 0;
    margin-bottom: 1rem;
}
.uksc-tab-content input, .uksc-tab-content select {
    width: 100%;
    padding: 0.7rem;
    border: 1px solid var(--uksc-medium-gray);
    border-radius: 4px;
}
.uksc-input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}
.uksc-input-group input { flex-grow: 1; }
.uksc-input-group select { width: auto; }
.uksc-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}
.uksc-tax-year label {
    margin-right: 0.5rem;
}
.uksc-calculate-btn {
    background-color: var(--uksc-primary-color);
    color: white;
    padding: 0.8rem 2.5rem;
    border: none;
    border-radius: var(--uksc-border-radius);
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}
.uksc-calculate-btn:hover {
    background-color: var(--uksc-primary-hover);
    transform: translateY(-2px);
}
.uksc-calculate-btn:disabled {
    background-color: #aaa;
    cursor: not-allowed;
    transform: none;
}
.uksc-results-wrapper {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px dashed var(--uksc-medium-gray);
    display: none;
    animation: fadeIn 0.5s;
}
.uksc-results-main {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 2rem;
    align-items: center;
}
.uksc-results-chart-container {
    position: relative;
    height: 350px;
}
.uksc-result-box {
    padding: 1.5rem;
    border-radius: var(--uksc-border-radius);
    text-align: center;
    background: #e8f5e9;
    border: 1px solid #c8e6c9;
    margin-bottom: 1.5rem;
}
.uksc-result-box.take-home .uksc-yearly-val {
    color: var(--uksc-primary-color);
}
.uksc-result-box h4 {
    margin: 0 0 0.5rem 0;
    font-size: 1rem;
    font-weight: normal;
}
.uksc-result-box .uksc-yearly-val { font-size: 1.8rem; font-weight: bold; }
.uksc-result-box .uksc-period-val { font-size: 1.2rem; color: #777; }
.uksc-results-summary h4 {
    margin-top: 0;
    margin-bottom: 0.5rem;
}
.uksc-breakdown-list {
    list-style: none;
    padding: 0;
    margin: 0;
    border: 1px solid var(--uksc-medium-gray);
    border-radius: var(--uksc-border-radius);
    overflow: hidden;
}
.uksc-breakdown-list li {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--uksc-light-gray);
}
.uksc-breakdown-list li:last-child { border-bottom: none; }
.uksc-breakdown-list li:nth-child(even) { background: var(--uksc-light-gray); }
.uksc-breakdown-list li span:last-child { font-weight: 600; }
.uksc-deduction-item span:last-child { color: var(--uksc-error-color); }
.uksc-total-item {
    font-weight: bold;
    border-top: 2px solid var(--uksc-dark-gray);
    background: #e0e0e0 !important;
}
.uksc-error-wrapper {
    display: none;
    margin-top: 1rem;
    padding: 1rem;
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    border-radius: var(--uksc-border-radius);
}
.uksc-input-toggle {
    margin-bottom: 1.5rem;
    display: flex;
    gap: 1.5rem;
    border-bottom: 1px solid var(--uksc-medium-gray);
    padding-bottom: 1rem;
}
.uksc-overtime-panel {
    padding-top: 1rem;
}
.uksc-overtime-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.uksc-small-input {
    width: 60px !important;
    text-align: center;
    padding: 0.5rem !important;
}
#uksc-overtime-by-cash .uksc-input-group {
    flex-wrap: wrap;
}
#uksc-overtime-by-cash .uksc-input-group input {
    width: 100px !important;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}
@media (max-width: 900px) {
    .uksc-results-main {
        grid-template-columns: 1fr;
    }
}
@media (max-width: 768px) {
    .uksc-calculator-wrapper {
        padding: 1rem;
    }
    .uksc-title {
        font-size: 1.5rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    .uksc-salary-input {
        width: 100%;
        margin-left: 0;
    }
    .uksc-footer {
        flex-direction: column;
        align-items: stretch;
    }
    .uksc-calculate-btn {
        width: 100%;
        padding: 1rem;
    }
}