/* ── 计算类型切换 Tab ── */
.calc-tabs {
    display: flex;
    gap: 0;
    margin-bottom: 1.5rem;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    overflow: hidden;
}

.calc-tab {
    flex: 1;
    padding: 0.7rem 1rem;
    border: none;
    background: #fafafa;
    color: #666;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.calc-tab + .calc-tab {
    border-left: 1px solid #e0e0e0;
}

.calc-tab.active {
    background: #2563eb;
    color: white;
}

.calc-tab:hover:not(.active) {
    background: #f0f0f0;
}

/* ── 存款表单 4 列 ── */
.calc-form {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 1.2rem;
    margin-bottom: 1.4rem;
}

/* ── 贷款表单 3 列 ── */
.calc-form-3col {
    grid-template-columns: 1fr 1fr 1fr;
}

/* ── 输入框 + 单位选择组合 ── */
.input-with-unit {
    display: flex;
    gap: 0;
}

.input-with-unit .form-input {
    flex: 1;
    border-radius: 6px 0 0 6px;
    min-width: 0;
}

.form-unit {
    padding: 0.7rem 0.6rem;
    border: 1px solid #e0e0e0;
    border-left: none;
    border-radius: 0 6px 6px 0;
    font-size: 0.9rem;
    font-family: inherit;
    background: #fafafa;
    color: #555;
    cursor: pointer;
}

.form-unit:focus {
    outline: none;
    border-color: #2563eb;
    background: white;
}

/* ── 存款结果卡片 ── */
.result-card {
    background: #f8f9fb;
    border: 1px solid #e8eaf0;
    border-radius: 8px;
    overflow: hidden;
    margin-top: 1.4rem;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.7rem 1.2rem;
    font-size: 0.9rem;
    border-top: 1px solid #f0f0f0;
}

.result-row:first-child {
    border-top: none;
}

.result-row span {
    color: #666;
}

.result-row strong {
    color: #333;
    font-family: 'Fira Code', monospace;
    font-weight: 600;
}

.result-row.highlight {
    background: #eef2ff;
}

.result-row.highlight span {
    color: #2563eb;
    font-weight: 500;
}

.result-row.highlight strong {
    color: #2563eb;
    font-size: 1.05rem;
    font-weight: 700;
}

.result-row.total {
    background: white;
    border-top: 2px solid #e8eaf0;
}

.result-row.total span {
    color: #333;
    font-weight: 600;
}

.result-row.total strong {
    color: #2563eb;
    font-weight: 700;
    font-size: 1.05rem;
}

/* ── 公式说明区 ── */
.formula-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
}

.formula-card {
    background: #f8f9fb;
    border: 1px solid #e8eaf0;
    border-radius: 10px;
    padding: 1.5rem;
}

.formula-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 0.6rem;
}

.formula-expr {
    font-family: 'Fira Code', monospace;
    font-size: 1.1rem;
    font-weight: 600;
    color: #2563eb;
    background: white;
    border: 1px solid #e8eaf0;
    border-radius: 6px;
    padding: 0.6rem 1rem;
    margin-bottom: 0.8rem;
    text-align: center;
}

.formula-desc {
    font-size: 0.85rem;
    color: #666;
    line-height: 1.7;
}

.formula-desc p {
    margin-bottom: 0.3rem;
}

.formula-desc p:last-child {
    margin-bottom: 0;
}

/* ── Mobile ── */
@media (max-width: 900px) {
    .calc-form {
        grid-template-columns: 1fr 1fr;
    }
    .calc-form-3col {
        grid-template-columns: 1fr 1fr;
    }
    .formula-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 640px) {
    .calc-form {
        grid-template-columns: 1fr;
    }
    .calc-form-3col {
        grid-template-columns: 1fr;
    }
    .formula-grid {
        grid-template-columns: 1fr;
    }
}