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

:root {
    --primary-color: #1e293b;
    --secondary-color: #3b82f6;
    --accent-color: #059669;
    --warning-color: #dc2626;
    --text-color: #374151;
    --light-text: #6b7280;
    --bg-color: #f8fafc;
    --white: #ffffff;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --legal-blue: #1e40af;
    --legal-gold: #d97706;
}

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

.calculator-container {
    min-height: 100vh;
}

.calculator-header {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-content h1 {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--primary-color);
}

.back-btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 500;
    transition: var(--transition);
}

.back-btn:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

.calculator-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.intro-section {
    margin-bottom: 2rem;
}

.intro-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.intro-card h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.intro-card p {
    color: var(--text-color);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.disclaimer {
    background: #fef3c7;
    border: 1px solid #f59e0b;
    border-radius: 0.5rem;
    padding: 1rem;
    color: #92400e;
    font-size: 0.9rem;
    line-height: 1.6;
}

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

.input-panel, .results-panel {
    background: var(--white);
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    height: fit-content;
}

.input-panel h3, .results-panel h3 {
    color: var(--primary-color);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border-color);
}

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

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

.form-group input, .form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: var(--transition);
    background: var(--white);
    color: var(--text-color);
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.field-note {
    font-size: 0.875rem;
    color: var(--light-text);
    margin-top: 0.5rem;
    font-style: italic;
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: normal;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 0.25rem;
    transition: var(--transition);
}

.checkbox-label:hover {
    background: #f1f5f9;
}

.checkbox-label input[type="checkbox"] {
    width: auto;
    margin: 0;
    transform: scale(1.1);
}

.calculate-btn {
    width: 100%;
    padding: 1rem 2rem;
    background: var(--legal-blue);
    color: var(--white);
    border: none;
    border-radius: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.calculate-btn:hover {
    background: #1e3a8a;
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.calculate-btn:disabled {
    background: var(--light-text);
    cursor: not-allowed;
    transform: none;
}

.results-content {
    min-height: 200px;
}

.no-results {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    color: var(--light-text);
    text-align: center;
}

.result-item {
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--legal-blue);
}

.result-item.urgent {
    background: #fef2f2;
    border-left-color: var(--warning-color);
}

.result-item.normal {
    background: #f0f9ff;
    border-left-color: var(--secondary-color);
}

.result-item.extended {
    background: #f0fdf4;
    border-left-color: var(--accent-color);
}

.result-title {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.result-date {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.result-date.urgent {
    color: var(--warning-color);
}

.result-date.normal {
    color: var(--secondary-color);
}

.result-date.extended {
    color: var(--accent-color);
}

.result-note {
    font-size: 0.9rem;
    color: var(--light-text);
    font-style: italic;
}

.days-remaining {
    font-size: 0.9rem;
    font-weight: 600;
    margin-top: 0.5rem;
}

.reference-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.reference-card, .tips-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.reference-card h3, .tips-card h3 {
    color: var(--primary-color);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.reference-grid {
    display: grid;
    gap: 1rem;
}

.reference-item {
    padding: 1rem;
    background: #f8fafc;
    border-radius: 0.5rem;
    border-left: 3px solid var(--legal-gold);
    font-size: 0.9rem;
    line-height: 1.5;
}

.tips-list {
    list-style: none;
    padding: 0;
}

.tips-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
    line-height: 1.6;
}

.tips-list li:last-child {
    border-bottom: none;
}

.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--secondary-color);
    animation: spin 1s ease-in-out infinite;
    margin-right: 0.5rem;
}

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

@media (max-width: 768px) {
    .calculator-content {
        padding: 1rem;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .header-content h1 {
        font-size: 1.5rem;
    }
    
    .calculator-section {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .reference-section {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .input-panel, .results-panel {
        padding: 1.5rem;
    }
    
    .intro-card {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .calculator-content {
        padding: 0.5rem;
    }
    
    .input-panel, .results-panel, .intro-card, .reference-card, .tips-card {
        padding: 1rem;
    }
    
    .header-content h1 {
        font-size: 1.25rem;
    }
}