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

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

.container {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

h1 {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
    font-size: 28px;
}

.tabs {
    display: flex;
    background: #f8f9fa;
    border-bottom: 2px solid #e9ecef;
}

.tab-btn {
    flex: 1;
    padding: 15px;
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    color: #6c757d;
    transition: all 0.3s;
}

.tab-btn.active {
    color: #667eea;
    background: white;
    border-bottom: 3px solid #667eea;
}

.tab-btn:hover {
    background: #e9ecef;
}

.form-container {
    padding: 30px;
}

.section {
    margin-bottom: 30px;
}

.section h2 {
    color: #333;
    font-size: 18px;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid #667eea;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: #495057;
    margin-bottom: 5px;
}

.form-group input,
textarea {
    padding: 10px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s;
}

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

textarea {
    resize: vertical;
    font-family: inherit;
    width: 100%;
}

/* 项目明细 */
#itemsContainer {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.item-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr auto;
    gap: 10px;
    align-items: center;
}

.item-row input {
    padding: 10px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 14px;
}

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

/* 按钮样式 */
.btn-add {
    margin-top: 10px;
    padding: 10px 20px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.3s;
}

.btn-add:hover {
    background: #218838;
}

.btn-remove {
    padding: 10px 15px;
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.3s;
}

.btn-remove:hover {
    background: #c82333;
}

.button-group {
    display: flex;
    gap: 15px;
    margin-top: 30px;
}

.btn-primary,
.btn-secondary {
    flex: 1;
    padding: 15px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .item-row {
        grid-template-columns: 1fr;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .button-group {
        flex-direction: column;
    }
}