* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: #f5f5f7;
    min-height: 100vh;
    padding-top: 80px;
}

/* Header Styles */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    z-index: 1000;
    border-bottom: 1px solid #e5e5ea;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo img {
    height: 40px;
    width: auto;
    transition: transform 0.3s ease;
}

.logo:hover img {
    transform: scale(1.05);
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 5px;
}

.main-nav a {
    color: #1d1d1f;
    text-decoration: none;
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.main-nav a:hover {
    background: #f5f5f7;
    color: #5e5ce6;
}

.main-nav a.active {
    background: #5e5ce6;
    color: white;
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background: #1d1d1f;
    border-radius: 3px;
    transition: all 0.3s ease;
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Responsive Header */
@media (max-width: 768px) {
    body {
        padding-top: 0 !important;
    }

    .site-header {
        position: relative;
    }

    .header-container {
        padding: 12px 20px;
    }

    .logo img {
        height: 35px;
    }

    .menu-toggle {
        display: flex;
    }

    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    }

    .main-nav.active {
        max-height: 400px;
        border-bottom: 1px solid #e5e5ea;
    }

    .main-nav a {
        width: 100%;
        padding: 15px 20px;
        border-radius: 0;
        border-bottom: 1px solid #f5f5f7;
        text-align: left;
    }

    .main-nav a:last-child {
        border-bottom: none;
    }
}

.container {
    max-width: 800px;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
    margin: 40px auto;
    padding: 0 20px;
}

.calculator-card,
.info-card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.calculator-card {
    animation: slideInLeft 0.5s ease-out;
}

.info-card {
    animation: slideInRight 0.5s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

h1 {
    color: #1d1d1f;
    font-size: 28px;
    margin-bottom: 10px;
    text-align: center;
    font-weight: 700;
}

.subtitle {
    color: #86868b;
    text-align: center;
    margin-bottom: 30px;
    font-size: 14px;
}

.input-group {
    margin-bottom: 25px;
}

.input-group label {
    display: block;
    color: #1d1d1f;
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 14px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    width: 100%;
    padding: 15px 45px;
    border: 1px solid #d2d2d7;
    border-radius: 10px;
    font-size: 18px;
    transition: all 0.3s ease;
    outline: none;
    background: #fafafa;
}

.input-wrapper input:focus {
    border-color: #5e5ce6;
    box-shadow: 0 0 0 3px rgba(94, 92, 230, 0.1);
    background: white;
}

.currency-symbol,
.percent-symbol {
    position: absolute;
    color: #86868b;
    font-size: 18px;
    font-weight: 600;
}

.currency-symbol {
    left: 18px;
}

.percent-symbol {
    right: 18px;
}

.calculate-btn,
.reset-btn {
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.calculate-btn {
    background: #30d5c8;
    color: white;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(48, 213, 200, 0.3);
    background: #2bc4b8;
}

.calculate-btn:active {
    transform: translateY(0);
}

.reset-btn {
    background: #f5f5f7;
    color: #86868b;
    margin-top: 15px;
    border: 1px solid #d2d2d7;
}

.reset-btn:hover {
    background: #e8e8ed;
}

.results {
    margin-top: 20px;
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-card {
    background: #fafafa;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 15px;
    transition: all 0.3s ease;
    border: 1px solid #e5e5ea;
}

.result-card:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
}

.result-card.highlight {
    background: #5e5ce6;
    border: 1px solid #5e5ce6;
}

.result-card.highlight .result-label,
.result-card.highlight .result-value {
    color: white;
}

.result-label {
    color: #86868b;
    font-size: 14px;
    margin-bottom: 8px;
    font-weight: 500;
}

.result-value {
    color: #1d1d1f;
    font-size: 32px;
    font-weight: 700;
}

.breakdown {
    background: #f5f5f7;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
    border-left: 4px solid #5e5ce6;
    border: 1px solid #e5e5ea;
}

.breakdown h3 {
    color: #1d1d1f;
    font-size: 18px;
    margin-bottom: 15px;
}

.breakdown-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    color: #86868b;
    font-size: 15px;
}

.breakdown-item.total {
    color: #1d1d1f;
    font-weight: 700;
    font-size: 18px;
}

.breakdown-divider {
    border-top: 2px solid #d2d2d7;
    margin: 10px 0;
}

.info-card h2 {
    color: #1d1d1f;
    font-size: 24px;
    margin-bottom: 20px;
}

.info-card h3 {
    color: #1d1d1f;
    font-size: 18px;
    margin-top: 25px;
    margin-bottom: 15px;
}

.info-card ol,
.info-card ul {
    padding-left: 25px;
    color: #86868b;
    line-height: 1.8;
}

.info-card li {
    margin-bottom: 10px;
}

.formula-section {
    background: #fafafa;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
    border: 1px solid #e5e5ea;
}

.formula {
    background: white;
    padding: 15px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    color: #5e5ce6;
    font-weight: 600;
    margin: 10px 0;
    border-left: 4px solid #5e5ce6;
    border: 1px solid #e5e5ea;
}

.example-section {
    background: #f0f9ff;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
    border-left: 4px solid #30d5c8;
    border: 1px solid #e5e5ea;
}

.example-section p {
    color: #86868b;
    line-height: 1.8;
    margin-bottom: 10px;
}

@media (max-width: 968px) {
    .container {
        grid-template-columns: 1fr;
        margin: 20px auto;
    }

    body {
        padding: 10px 0;
    }

    .calculator-card,
    .info-card {
        padding: 25px;
    }
}

/* Error state */
input.error {
    border-color: #f44336 !important;
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* Loading animation */
.calculate-btn.loading {
    pointer-events: none;
    opacity: 0.7;
}

.calculate-btn.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    top: 50%;
    left: 50%;
    margin-left: -10px;
    margin-top: -10px;
    border: 3px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Accessibility - Skip to main content */
.skip-to-main {
    position: absolute;
    top: -40px;
    left: 0;
    background: #5e5ce6;
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 0 0 4px 0;
    z-index: 100;
}

.skip-to-main:focus {
    top: 0;
}

/* Screen reader only text */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Formula explanation */
.formula-explanation {
    margin-top: 15px;
    color: #86868b;
    font-size: 14px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
}

.example-note {
    margin-top: 15px;
    color: #1d1d1f;
    font-weight: 500;
    font-size: 14px;
}

/* FAQ Section */
/* Tax Tables Section */
.tax-rates-section {
    max-width: 1200px;
    margin: 60px auto 40px;
    padding: 0 20px;
}

.tax-rates-section .content-container {
    background: white;
    border-radius: 20px;
    padding: 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.tax-rates-section h2 {
    color: #1d1d1f;
    font-size: 32px;
    margin-bottom: 20px;
    font-weight: 700;
}

.tax-rates-section h3 {
    color: #1d1d1f;
    font-size: 24px;
    margin-top: 40px;
    margin-bottom: 15px;
    font-weight: 600;
}

.table-responsive {
    overflow-x: auto;
    margin: 20px 0;
}

.tax-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.tax-table thead {
    background: #5e5ce6;
    color: white;
}

.tax-table thead th {
    padding: 15px;
    text-align: left;
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.tax-table tbody tr {
    border-bottom: 1px solid #e5e5ea;
    transition: background-color 0.2s ease;
}

.tax-table tbody tr:hover {
    background-color: #f5f5f7;
}

.tax-table tbody tr:last-child {
    border-bottom: none;
}

.tax-table tbody td {
    padding: 15px;
    color: #1d1d1f;
    font-size: 15px;
}

.tax-table tbody td:first-child {
    font-weight: 600;
}

.table-note {
    font-size: 14px;
    color: #86868b;
    font-style: italic;
    margin-top: 10px;
}

/* Understanding Section */
.understanding-section {
    max-width: 1200px;
    margin: 60px auto 40px;
    padding: 0 20px;
}

.understanding-section .content-container {
    background: white;
    border-radius: 20px;
    padding: 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.understanding-section h2 {
    color: #1d1d1f;
    font-size: 32px;
    margin-bottom: 20px;
    font-weight: 700;
}

.understanding-section h3 {
    color: #1d1d1f;
    font-size: 22px;
    margin-top: 30px;
    margin-bottom: 15px;
    font-weight: 600;
}

.understanding-section p {
    color: #86868b;
    line-height: 1.8;
    margin-bottom: 15px;
}

.understanding-section ul {
    padding-left: 25px;
    color: #86868b;
    line-height: 1.8;
    margin-bottom: 20px;
}

.understanding-section li {
    margin-bottom: 10px;
}

/* References Section */
.references-section {
    max-width: 1200px;
    margin: 60px auto 40px;
    padding: 0 20px;
}

.references-section .content-container {
    background: white;
    border-radius: 20px;
    padding: 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.references-section h2 {
    color: #1d1d1f;
    font-size: 32px;
    margin-bottom: 20px;
    font-weight: 700;
}

.references-section h3 {
    color: #1d1d1f;
    font-size: 22px;
    margin-top: 30px;
    margin-bottom: 15px;
    font-weight: 600;
}

.references-section p {
    color: #86868b;
    line-height: 1.8;
    margin-bottom: 20px;
}

.references-list {
    list-style: none;
    padding-left: 0;
    margin-bottom: 20px;
}

.references-list li {
    color: #86868b;
    line-height: 1.8;
    margin-bottom: 15px;
    padding-left: 25px;
    position: relative;
}

.references-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: #5e5ce6;
    font-weight: bold;
}

.references-list a {
    color: #5e5ce6;
    text-decoration: none;
    transition: color 0.2s ease;
}

.references-list a:hover {
    color: #4a4ac4;
    text-decoration: underline;
}

.faq-section {
    max-width: 1200px;
    margin: 60px auto 40px;
    padding: 0 20px;
}

.faq-container {
    background: white;
    border-radius: 20px;
    padding: 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.faq-container h2 {
    color: #1d1d1f;
    font-size: 32px;
    margin-bottom: 40px;
    text-align: center;
    font-weight: 700;
}

.faq-item {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid #e5e5ea;
}

.faq-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.faq-question {
    color: #1d1d1f;
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 15px;
    line-height: 1.4;
}

.faq-answer {
    color: #86868b;
    font-size: 16px;
    line-height: 1.8;
    margin: 0;
}

/* Content Section */
.content-section {
    max-width: 1200px;
    margin: 40px auto 60px;
    padding: 0 20px;
}

.content-container {
    background: white;
    border-radius: 20px;
    padding: 50px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 1px solid #e5e5ea;
}

.content-container h2 {
    color: #1d1d1f;
    font-size: 32px;
    margin-bottom: 25px;
    font-weight: 700;
}

.content-container h3 {
    color: #1d1d1f;
    font-size: 24px;
    margin-top: 40px;
    margin-bottom: 20px;
    font-weight: 600;
}

.content-container p {
    color: #86868b;
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 20px;
}

.content-container ul {
    color: #86868b;
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 20px;
    padding-left: 30px;
}

.content-container li {
    margin-bottom: 12px;
}

.content-container strong {
    color: #1d1d1f;
    font-weight: 600;
}

.features-list {
    background: #fafafa;
    padding: 25px 25px 25px 55px;
    border-radius: 10px;
    border-left: 4px solid #5e5ce6;
    margin: 25px 0;
}

.features-list li {
    margin-bottom: 15px;
}

/* Footer */
.site-footer {
    background: #1d1d1f;
    color: #86868b;
    padding: 40px 20px;
    text-align: center;
    margin-top: 60px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-content p {
    margin-bottom: 10px;
    font-size: 14px;
    line-height: 1.6;
}

.footer-note {
    color: #6e6e73;
    font-size: 12px;
}

/* Responsive adjustments for new sections */
@media (max-width: 968px) {
    .faq-container,
    .content-container {
        padding: 30px 25px;
    }

    .faq-container h2,
    .content-container h2 {
        font-size: 26px;
    }

    .faq-question {
        font-size: 18px;
    }

    .content-container h3 {
        font-size: 20px;
    }

    .faq-section,
    .content-section,
    .tax-rates-section,
    .understanding-section,
    .references-section {
        margin: 40px auto 30px;
    }

    .tax-rates-section .content-container,
    .understanding-section .content-container,
    .references-section .content-container,
    .faq-container {
        padding: 30px 20px;
    }

    .tax-table thead th,
    .tax-table tbody td {
        padding: 10px 8px;
        font-size: 13px;
    }

    .tax-table {
        font-size: 14px;
    }

    .tax-rates-section h2,
    .understanding-section h2 {
        font-size: 24px;
    }

    .tax-rates-section h3,
    .understanding-section h3 {
        font-size: 18px;
        margin-top: 25px;
    }
}