/* ===== CSS Variables ===== */
:root {
    /* Colors - Light Theme */
    --bg-page: #f8fafc;
    --bg-white: #ffffff;
    --bg-gray-50: #f9fafb;
    --bg-gray-100: #f3f4f6;

    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --text-light: #9ca3af;

    --accent-blue: #3b82f6;
    --accent-blue-dark: #2563eb;
    --accent-blue-light: #eff6ff;
    --accent-indigo: #4f46e5;
    --accent-green: #22c55e;
    --accent-green-light: #dcfce7;
    --accent-red: #ef4444;
    --accent-red-light: #fef2f2;
    --accent-orange: #f59e0b;

    --border-color: #e5e7eb;
    --border-light: #f3f4f6;

    --gradient-hero: linear-gradient(135deg, #4f46e5 0%, #3b82f6 50%, #0ea5e9 100%);
    --gradient-savings: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.08);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-page);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* ===== Header ===== */
.header {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    font-size: 1.75rem;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}

.logo-name .highlight {
    color: var(--accent-blue);
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.nav {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-gray-100);
}

.nav-link.active {
    color: var(--accent-blue);
    background: var(--accent-blue-light);
}

.cta-btn {
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
}

.cta-btn:hover {
    background: var(--accent-blue-dark);
}

/* ===== Hero Section ===== */
.hero {
    background: var(--gradient-hero);
    color: white;
    padding: 2.5rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 100%;
}

.hero-content h1 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.hero-subtitle {
    font-size: 1rem;
    opacity: 0.9;
}

.hero-badges {
    display: flex;
    gap: var(--spacing-md);
}

.badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.dot-red {
    background: #fca5a5;
}

.dot-green {
    background: #86efac;
}

/* ===== Control Tabs ===== */
.control-tabs {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg) 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 1.25rem;
    border: 1px solid var(--border-color);
    background: var(--bg-white);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.tab-btn:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

.tab-btn.active {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
}

.tab-icon {
    font-size: 1rem;
}

/* ===== Calculator Grid ===== */
.calculator-section {
    max-width: 1400px;
    margin: 0 auto;
}

.calculator-grid {
    display: grid;
    grid-template-columns: 340px 1fr;
    gap: var(--spacing-xl);
    padding: var(--spacing-xl);
}

/* ===== Input Sidebar ===== */
.input-sidebar {
    position: sticky;
    top: 80px;
    height: fit-content;
}

.input-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
}

.card-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.title-icon {
    font-size: 1.25rem;
}

/* Input Groups */
.input-group {
    margin-bottom: var(--spacing-lg);
}

.input-group label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.required {
    color: var(--accent-red);
}

.tooltip-icon {
    color: var(--text-light);
    cursor: help;
    font-size: 0.8rem;
}

.input-wrapper {
    position: relative;
}

.input-wrapper input {
    width: 100%;
    padding: 0.75rem 1rem;
    padding-right: 50px;
    background: var(--bg-gray-50);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--accent-blue);
    background: var(--bg-white);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.input-suffix {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Quick Select Buttons */
.quick-select {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.quick-btn {
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--border-color);
    background: var(--bg-white);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.quick-btn:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

.quick-btn.active {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: white;
}

/* Stepper */
.stepper {
    display: flex;
    align-items: center;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--bg-gray-50);
}

.stepper-btn {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-white);
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition-fast);
}

.stepper-btn:hover {
    background: var(--bg-gray-100);
}

.stepper-btn:active {
    background: var(--accent-blue);
    color: white;
}

.stepper input {
    flex: 1;
    text-align: center;
    border: none;
    background: transparent;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Radio Group */
.radio-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.radio-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition-fast);
}

.radio-label:hover {
    border-color: var(--accent-blue);
}

.radio-label input {
    display: none;
}

.radio-custom {
    width: 18px;
    height: 18px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.radio-label input:checked+.radio-custom {
    border-color: var(--accent-blue);
}

.radio-label input:checked+.radio-custom::after {
    content: '';
    width: 10px;
    height: 10px;
    background: var(--accent-blue);
    border-radius: 50%;
}

.radio-text {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-primary);
}

.radio-sub {
    color: var(--text-muted);
    font-weight: 400;
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
}

.checkbox-label input {
    display: none;
}

.checkbox-custom {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.checkbox-label input:checked+.checkbox-custom {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
}

.checkbox-label input:checked+.checkbox-custom::after {
    content: '✓';
    color: white;
    font-size: 12px;
    font-weight: 700;
}

.checkbox-text {
    font-size: 0.9rem;
    color: var(--text-primary);
}

.checkbox-rate {
    color: var(--text-muted);
}

.insurance-total {
    margin-left: auto;
    background: var(--accent-blue-light);
    color: var(--accent-blue);
    padding: 0.25rem 0.5rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

/* ===== Results Section ===== */
.results-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Info Bar */
.info-bar {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.info-icon {
    font-size: 1rem;
}

.law-info {
    flex: 1;
}

.law-badge {
    background: var(--accent-green-light);
    color: var(--accent-green);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-left: var(--spacing-sm);
}

.export-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: var(--bg-white);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.export-btn:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

/* Savings Banner */
.savings-banner {
    background: var(--gradient-savings);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    color: white;
}

.savings-icon {
    font-size: 2.5rem;
}

.savings-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

.savings-amount {
    font-size: 2rem;
    font-weight: 800;
    margin: 0.25rem 0;
}

.savings-unit {
    font-size: 1rem;
    font-weight: 400;
}

.savings-sub {
    font-size: 0.875rem;
    opacity: 0.9;
}

/* Comparison Grid */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.result-column {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
}

.column-header {
    margin-bottom: var(--spacing-lg);
}

.column-badge {
    display: inline-block;
    padding: 0.375rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.column-badge.old {
    background: var(--bg-gray-100);
    color: var(--text-secondary);
}

.column-badge.new {
    background: var(--accent-blue-light);
    color: var(--accent-blue);
}

/* Result Rows */
.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-light);
}

.result-row:last-child {
    border-bottom: none;
}

.row-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.row-value {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

.result-row.deduction .row-value {
    color: var(--accent-red);
}

.result-row.highlight {
    background: var(--bg-gray-50);
    margin: 0 -1.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
}

.result-row.tax {
    padding: 1rem 0;
}

.tax-amount {
    font-size: 1.25rem;
    color: var(--accent-red);
}

.tax-amount.new {
    color: var(--accent-blue);
}

.result-row.net {
    padding-top: 1rem;
    margin-top: 0.5rem;
    border-top: 2px solid var(--border-color);
}

.net-amount {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--accent-green);
}

/* Breakdown Section */
.breakdown-section {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
}

.breakdown-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
}

.breakdown-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.breakdown-card {
    background: var(--bg-gray-50);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
}

.breakdown-card h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.bracket-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.bracket-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px dashed var(--border-color);
}

.bracket-item:last-child {
    border-bottom: none;
}

.bracket-rate {
    background: var(--bg-white);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-weight: 600;
    color: var(--accent-blue);
}

/* ===== Reference Section ===== */
.reference-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-2xl);
}

.reference-section h2 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xl);
}

.tables-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
}

.table-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-color);
}

.table-card h3 {
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
}

th {
    background: var(--bg-gray-50);
    font-weight: 600;
    color: var(--text-secondary);
}

tr:last-child td {
    border-bottom: none;
}

tr:hover td {
    background: var(--bg-gray-50);
}

/* ===== Footer ===== */
.footer {
    text-align: center;
    padding: var(--spacing-2xl);
    border-top: 1px solid var(--border-color);
    background: var(--bg-white);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-links {
    margin-top: var(--spacing-sm);
}

.footer-links a {
    color: var(--accent-blue);
    text-decoration: none;
}

.footer-links a:hover {
    text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }

    .input-sidebar {
        position: static;
    }

    .hero {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .header-inner {
        flex-wrap: wrap;
        gap: var(--spacing-md);
    }

    .nav {
        order: 3;
        width: 100%;
        justify-content: center;
    }

    .comparison-grid,
    .breakdown-grid,
    .tables-grid {
        grid-template-columns: 1fr;
    }

    .radio-group {
        grid-template-columns: 1fr;
    }

    .control-tabs {
        flex-wrap: wrap;
    }
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-column,
.savings-banner,
.breakdown-section {
    animation: fadeIn 0.3s ease forwards;
}

.savings-amount {
    animation: fadeIn 0.5s ease forwards;
    animation-delay: 0.2s;
}