* {
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', 'Malgun Gothic', sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    min-height: 100vh;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}
.calculator {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
    padding: 40px;
    max-width: 420px;
    width: 100%;
}
h1 {
    text-align: center;
    color: #1a1a2e;
    margin-bottom: 10px;
    font-size: 1.5rem;
}
.subtitle {
    text-align: center;
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 30px;
}
.form-group {
    margin-bottom: 24px;
}
label {
    display: block;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
    font-size: 0.95rem;
}
input[type="number"] {
    width: 100%;
    padding: 14px 18px;
    font-size: 1.1rem;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    transition: border-color 0.2s;
}
input[type="number"]:focus {
    outline: none;
    border-color: #0f3460;
}
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    opacity: 1;
}
.unit {
    color: #666;
    font-size: 0.85rem;
    margin-top: 4px;
}
.notice {
    font-size: 0.8rem;
    color: #555;
    background: #f0f4f8;
    padding: 10px 14px;
    border-radius: 10px;
    margin-bottom: 20px;
    border-left: 3px solid #0f3460;
}
select {
    width: 100%;
    padding: 14px 18px;
    font-size: 1rem;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    background: white;
    cursor: pointer;
    transition: border-color 0.2s;
}
select:focus {
    outline: none;
    border-color: #0f3460;
}
.breakdown {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid #e0e0e0;
    font-size: 0.9rem;
}
.breakdown-row {
    display: flex;
    justify-content: space-between;
    margin: 6px 0;
    color: #444;
}
.breakdown-row.deduction {
    color: #0a6b2d;
}
.breakdown-row.total {
    margin-top: 12px;
    font-weight: 700;
    font-size: 1rem;
    color: #1a1a2e;
}
button {
    width: 100%;
    padding: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, #0f3460 0%, #16213e 100%);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
}
button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(15, 52, 96, 0.4);
}
button:active {
    transform: translateY(0);
}
.result {
    margin-top: 28px;
    padding: 24px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 12px;
    border-left: 4px solid #0f3460;
}
.result.hidden {
    display: none;
}
.result-label {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 4px;
}
.result-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: #1a1a2e;
}
.result-value span {
    color: #0f3460;
}