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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --background-color: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 2rem 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: var(--radius-xl);
    color: white;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-lg);
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

header .subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Main Content */
main {
    flex: 1;
}

/* Calculator Section */
.calculator-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

@media (min-width: 768px) {
    .calculator-section {
        grid-template-columns: 1fr 1fr;
    }
}

/* Cards */
.input-card,
.results-card,
.chart-card,
.breakdown-card {
    background: var(--card-background);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.input-card h2,
.results-card h2,
.chart-card h2,
.breakdown-card h2 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--primary-color);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--card-background);
    color: var(--text-primary);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input:hover,
.form-group select:hover {
    border-color: var(--primary-light);
}

/* Calculate Button */
.calculate-btn {
    width: 100%;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 0.5rem;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.result-item {
    background: var(--background-color);
    padding: 1rem;
    border-radius: var(--radius-md);
    text-align: center;
}

.result-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.result-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.result-value.highlight {
    color: var(--secondary-color);
}

/* Chart Section */
.chart-section {
    margin-bottom: 2rem;
}

.chart-container {
    position: relative;
    height: 400px;
    width: 100%;
}

@media (max-width: 768px) {
    .chart-container {
        height: 300px;
    }
}

/* Breakdown Section */
.breakdown-section {
    margin-bottom: 2rem;
}

.table-container {
    overflow-x: auto;
    max-height: 400px;
    overflow-y: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

thead {
    position: sticky;
    top: 0;
    background: var(--card-background);
    z-index: 1;
}

th {
    padding: 1rem 0.75rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border-color);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

td {
    padding: 0.875rem 0.75rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

tbody tr:hover {
    background-color: var(--background-color);
}

tbody tr:last-child td {
    font-weight: 700;
    background-color: rgba(37, 99, 235, 0.05);
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

footer p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

footer a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

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

.input-card,
.results-card,
.chart-card,
.breakdown-card {
    animation: fadeIn 0.5s ease-out;
}

.results-card {
    animation-delay: 0.1s;
}

.chart-card {
    animation-delay: 0.2s;
}

.breakdown-card {
    animation-delay: 0.3s;
}

/* Responsive Adjustments */
@media (max-width: 640px) {
    header h1 {
        font-size: 1.5rem;
    }

    header .subtitle {
        font-size: 0.95rem;
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .result-item {
        padding: 0.875rem;
    }

    .result-value {
        font-size: 1.1rem;
    }

    th, td {
        padding: 0.625rem 0.5rem;
    }

    .input-card,
    .results-card,
    .chart-card,
    .breakdown-card {
        padding: 1.25rem;
    }
}

/* Number input spinner removal for cleaner look */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    -moz-appearance: textfield;
}

/* Scrollbar styling */
.table-container::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.table-container::-webkit-scrollbar-track {
    background: var(--background-color);
    border-radius: 4px;
}

.table-container::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.table-container::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}