:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --accent: #10b981;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    line-height: 1.5;
    padding: 2rem 1rem;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-muted);
    font-size: 1.125rem;
}

.calculator-grid {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (max-width: 850px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }
}

.input-section {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    height: fit-content;
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-main);
    font-size: 0.9rem;
}

.input-group input, .input-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s;
}

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

#calculate-btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: background-color 0.2s;
}

#calculate-btn:hover {
    background-color: var(--primary-hover);
}

.results-section {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.summary-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

@media (max-width: 600px) {
    .summary-cards {
        grid-template-columns: 1fr;
    }
}

.card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.card .label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.card .value {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
}

.chart-container {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    min-height: 400px;
}

.table-section {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.table-section h2 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    text-align: center;
}

.table-wrapper {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

th {
    background: var(--bg);
    padding: 1rem;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.875rem;
    border-bottom: 2px solid var(--border);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border);
    font-variant-numeric: tabular-nums;
}

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

tr:hover td {
    background-color: rgba(37, 99, 235, 0.02);
}