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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

h1 {
    text-align: center;
    color: #333;
    font-size: 26px;
    font-weight: 700;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 3px solid #667eea;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.select-row {
    display: flex;
    gap: 10px;
}

.select-item {
    flex: 1;
}

.select-item select,
.form-group input {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
}

.select-item select:focus,
.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.input-row-three {
    display: flex;
    align-items: center;
    gap: 8px;
}

.input-row-three input {
    flex: 1;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
}

.input-row-three input:focus {
    outline: none;
    border-color: #667eea;
}

.separator {
    font-size: 18px;
    color: #999;
    font-weight: bold;
}

.radio-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.radio-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    cursor: pointer;
}

.radio-item:hover {
    border-color: #667eea;
    background: #f5f5ff;
}

.radio-item input[type="radio"] {
    width: 18px;
    height: 18px;
}

.btn-primary {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.btn-primary:hover {
    transform: translateY(-2px);
}

.result-box {
    margin-top: 24px;
    padding: 24px;
    background: linear-gradient(135deg, #667eea 0%, #5568d3 100%);
    border-radius: 12px;
    color: white;
}

.result-box h2 {
    font-size: 20px;
    margin-bottom: 16px;
    text-align: center;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid rgba(255,255,255,0.3);
    font-size: 15px;
}

.result-item:last-child {
    border-bottom: none;
}

.result-item.total {
    font-size: 18px;
    font-weight: bold;
    margin-top: 8px;
    padding-top: 16px;
    border-top: 2px solid rgba(255,255,255,0.5);
}

.material-recommendations {
    margin-top: 20px;
    padding: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
}

.material-recommendations h3 {
    font-size: 16px;
    margin-bottom: 12px;
}

.rec-item {
    background: rgba(255,255,255,0.9);
    color: #333;
    padding: 12px;
    border-radius: 6px;
    margin-bottom: 10px;
}

.rec-item.recommended {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
}

.rec-item.economic {
    background: #d4edda;
    border-left: 4px solid #28a745;
}

.rec-title {
    font-weight: bold;
    font-size: 15px;
    margin-bottom: 6px;
}

.rec-detail {
    font-size: 13px;
    color: #666;
    margin-bottom: 4px;
}

.calculation-detail {
    margin-top: 20px;
    padding: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
}

.calculation-detail h3 {
    font-size: 16px;
    margin-bottom: 12px;
}

.calc-step {
    font-size: 14px;
    margin-bottom: 8px;
    line-height: 1.6;
}

.calc-step.final {
    font-weight: bold;
    font-size: 16px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 2px solid rgba(255,255,255,0.3);
}