:root {
    --primary: #2563eb;
    --success: #22c55e;
    --warning: #f59e0b;
    --light: #f8fafc;
    --border: #e2e8f0;
    --text: #1e293b;
}

.tool-container {
    padding: 24px;
    max-width: 900px;
    margin: 0 auto;
}
.main-card {
    background: #fff;
    overflow: hidden;
}
.tab-header {
    display: flex;
    border-bottom: 1px solid var(--border);
}
.tab-btn {
    flex: 1;
    padding: 16px 12px;
    border: none;
    background: transparent;
    font-size: 15px;
    color: #64748b;
    cursor: pointer;
    transition: all 0.2s;
}
.tab-btn.active {
    color: var(--primary);
    font-weight: 600;
    border-bottom: 2px solid var(--primary);
}
.tab-btn:hover:not(.active) {
    background: var(--light);
}
.tab-content {
    padding: 24px;
}
.tab-pane {
    display: none;
}
.tab-pane.active {
    display: block;
}
.form-row {
    display: flex;
    align-items: center;
    margin-bottom: 16px;
    gap: 12px;
    flex-wrap: wrap;
}
.form-row label {
    width: 110px;
    font-weight: 500;
    color: #475569;
}
.form-row input,
.form-row select {
    flex: 1;
    min-width: 200px;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    outline: none;
    transition: border-color 0.2s;
}
.form-row input:focus,
.form-row select:focus {
    border-color: var(--primary);
}
.rate-quick {
    display: inline-flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-left: 10px;
}
.rate-quick span {
    font-size: 12px;
    padding: 3px 8px;
    background: #eef2ff;
    color: var(--primary);
    border-radius: 4px;
    cursor: pointer;
    white-space: nowrap;
}
.rate-quick span:hover {
    background: #ddd6fe;
}
.btn-calc {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 12px 32px;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-calc:hover {
    background: #1d4ed8;
}
.btn-reset {
    background: #94a3b8;
    color: #fff;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    margin-left: 10px;
}
.btn-reset:hover {
    background: #64748b;
}
.btn-copy {
    background: #10b981;
    color: #fff;
    border: none;
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 13px;
    cursor: pointer;
    margin-top: 12px;
}
.btn-copy:hover {
    background: #059669;
}
.result-card {
    margin-top: 24px;
    padding: 20px;
    border-radius: 12px;
    display: none;
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
}
.result-item {
    margin-bottom: 10px;
    font-size: 16px;
}
.result-item:last-child {
    margin-bottom: 0;
}
.result-label {
    font-weight: 500;
    color: #475569;
}
.result-value {
    font-weight: 600;
    margin-left: 8px;
    font-size: 17px;
}
.core-data {
    font-size: 20px;
    font-weight: 700;
    color: #16a34a;
}
.tip-text {
    font-size: 14px;
    color: #6b7280;
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px dashed #ddd;
}
.warn-text {
    font-size: 13px;
    color: #f59e0b;
    margin: 6px 0;
}