body {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Heebo Variablefont Wght', Arial, sans-serif;
    min-height: 100%;
    width: 100%;
}

.app-wrapper {
    box-sizing: border-box;
    width: 100%;
    min-height: 100%;
    padding: 2rem 1rem;
}

.app-wrapper * { box-sizing: border-box; }

.calculator-container {
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    border: 1px solid #e2e8f0;
    padding: 2.5rem;
    max-width: 700px;
    width: 100%;
    margin: 0 auto;
}

h1 { color: #1a202c; margin: 0 0 0.5rem 0; font-size: 2.25rem; font-weight: 700; text-align: center; line-height: 1.2; }
.subtitle { color: #4a5568; text-align: center; margin: 0 0 2.5rem 0; font-size: 1.125rem; font-weight: 400; }
.form-group { margin-bottom: 1.75rem; }
.form-group label { display: block; color: #2d3748; font-weight: 600; margin-bottom: 0.75rem; font-size: 1rem; }
.form-group input[type="date"] { width: 100%; padding: 1rem; border: 2px solid #cbd5e0; border-radius: 6px; font-size: 1rem; transition: all 0.2s ease; background: white; }
.form-group input[type="date"]:focus { outline: none; border-color: #3182ce; box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1); }

.checkbox-wrapper { display: flex; flex-direction: column; gap: 1rem; }
.checkbox-group { display: flex; align-items: center; padding: 1rem; background: #f7fafc; border: 2px solid #e2e8f0; border-radius: 6px; cursor: pointer; transition: all 0.2s ease; }
.checkbox-group:hover { background: #edf2f7; border-color: #cbd5e0; }
.checkbox-group input[type="checkbox"] { width: 20px; height: 20px; margin-right: 0.75rem; cursor: pointer; accent-color: #006e80; }
.checkbox-group label { margin: 0; cursor: pointer; flex: 1; font-weight: 500; font-size: 1rem; color: #2d3748; }

.button-group { display: flex; gap: 1rem; margin-top: 2.5rem; }
.button-group button { flex: 1; padding: 1rem 1.5rem; border: none; border-radius: 6px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: all 0.2s ease; }
.btn-calculate { background: #006e80; color: white; }
.btn-calculate:hover { background: #008496; }
.btn-reset { background: #e2e8f0; color: #4a5568; border: 1px solid #cbd5e0; }
.btn-reset:hover { background: #cbd5e0; }

.result-section { margin-top: 2.5rem; padding: 2rem; background: #006e80; border: 1px solid #e2e8f0; border-radius: 8px; display: none; }
.result-section.show { display: block; animation: slideIn 0.3s ease; }
@keyframes slideIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

.result-item { background: rgba(255,255,255,0.1); padding: 1.5rem; border-radius: 6px; margin-bottom: 1rem; }
.result-label { font-size: 0.875rem; opacity: 0.9; margin-bottom: 0.5rem; font-weight: 500; color: white; }
.result-value { font-size: 1.75rem; font-weight: 700; line-height: 1; color: white; }
.info-box { background: rgba(255,255,255,0.15); color: white; padding: 1rem; border-radius: 6px; margin-top: 1.5rem; font-size: 0.95rem; line-height: 1.6; }

.error-message { background: #fed7d7; color: #c53030; padding: 1rem; border-radius: 6px; border: 1px solid #feb2b2; margin-top: 1rem; display: none; font-size: 0.95rem; }
.error-message.show { display: block; }

@media (max-width: 768px) { .app-wrapper { padding: 1rem 0.5rem; } .calculator-container { padding: 2rem 1.5rem; } h1 { font-size: 1.875rem; } .subtitle { font-size: 1rem; } .button-group { flex-direction: column; } .result-value { font-size: 1.5rem; } }
@media (max-width: 480px) { .calculator-container { padding: 1.5rem 1rem; } h1 { font-size: 1.5rem; } .result-section { padding: 1.5rem; } }