.tool-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 30px 20px;
    box-sizing: border-box;
}
.oil-card {
    background: #fff;
    padding: 35px;
}
.main-title {
    font-size: 22px;
    color: #1f2937;
    font-weight: 600;
    text-align: center;
    margin-bottom: 25px;
}
/* 切换选项卡 */
.tab-box{display:flex;gap:10px;margin-bottom:25px;}
.tab-item{flex:1;text-align:center;padding:12px 0;border-radius:10px;border:1px solid #e5e7eb;cursor:pointer;font-size:15px;color:#666;transition:0.3s;}
.tab-item.active{background:#2774e7;color:#fff;border-color:#2774e7;}
.hide-box{display:none;}

.form-row {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 22px;
}
.form-item {
    flex: 1;
    min-width: 240px;
}
.form-item label {
    display: block;
    font-size: 14px;
    color: #4b5563;
    margin-bottom: 8px;
    font-weight: 500;
}
.form-item input,.form-item select {
    width: 100%;
    height: 44px;
    padding: 0 15px;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    font-size: 15px;
    background: #f9fafb;
    transition: all 0.25s ease;
    outline: none;
}
.form-item input:focus,.form-item select:focus {
    border-color: #2774e7;
    background: #fff;
    box-shadow: 0 0 0 3px rgba(39,116,231,0.15);
}
.calc-btn {
    width: 100%;
    height: 48px;
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, #2774e7, #1e64cd);
    color: #fff;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 15px 0 30px;
}
.calc-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(39,116,231,0.25);
}
.result-wrap {
    background: linear-gradient(135deg, #f0f7ff 0%, #eef6ff 100%);
    border-radius: 16px;
    padding: 28px;
    border: 1px solid #dbeafe;
}
.result-title {
    font-size: 18px;
    color: #1e40af;
    font-weight: 600;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
}
.result-title::before {
    content: "";
    width: 4px;
    height: 18px;
    background: #2774e7;
    margin-right: 10px;
    border-radius: 2px;
}
.result-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}
.result-item {
    background: #fff;
    padding: 16px 20px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.result-item .lab {
    font-size: 13px;
    color: #64748b;
    margin-bottom: 6px;
}
.result-item .num {
    font-size: 16px;
    color: #1e293b;
    font-weight: 600;
}
.result-big {
    margin-top: 20px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: #fff;
    padding: 22px 25px;
    border-radius: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.result-big .txt {
    font-size: 16px;
    opacity: 0.95;
}
.result-big .data {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
}
.tips-text {
    margin-top: 20px;
    font-size: 13px;
    color: #94a3b8;
    line-height: 1.6;
}
@media (max-width: 768px) {
    .result-grid {
        grid-template-columns: 1fr;
    }
    .oil-card {
        padding: 25px 20px;
    }
}