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

body {
    background: #f5f7fc;
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    padding: 20px 16px 32px;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    color: #1e293b;
}

.calculator {
    max-width: 1000px;
    width: 100%;
    background: white;
    border-radius: 28px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.06), 0 4px 8px rgba(0, 0, 0, 0.02);
    padding: 24px 22px 28px;
    transition: all 0.2s;
    border: 1px solid #eef2f6;
    position: relative;
}

/* 返回首页按钮 */
.back-home-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    align-items: center;
    gap: 6px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
    z-index: 100;
}

.back-home-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.5);
}

.back-home-btn i {
    font-size: 1rem;
}

h1 {
    font-size: 1.9rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-bottom: 6px;
    color: #0f172a;
    display: flex;
    align-items: center;
    gap: 8px;
}

.subhead {
    font-size: 0.9rem;
    color: #64748b;
    margin-bottom: 24px;
    border-left: 4px solid #3b82f6;
    padding-left: 16px;
    font-weight: 400;
}

.input-panel {
    display: flex;
    flex-wrap: wrap;
    gap: 20px 24px;
    background: #fafcff;
    padding: 20px 20px 16px;
    border-radius: 22px;
    margin-bottom: 28px;
    border: 1px solid #e2e8f0;
}

.form-group {
    flex: 1 1 200px;
    min-width: 180px;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    color: #475569;
    margin-bottom: 6px;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 12px 14px;
    font-size: 1rem;
    border: 1.5px solid #e2e8f0;
    border-radius: 18px;
    background: white;
    transition: border 0.15s, box-shadow 0.15s;
    font-weight: 500;
    color: #0f172a;
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-group input:disabled {
    background: #f1f5f9;
    color: #64748b;
    border-color: #cbd5e1;
    cursor: not-allowed;
}

.mode-group {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
    margin-top: 6px;
}

.radio-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.radio-item input[type="radio"] {
    width: 20px;
    height: 20px;
    accent-color: #2563eb;
    margin: 0;
}

.radio-item label {
    margin-bottom: 0;
    text-transform: none;
    font-weight: 500;
    font-size: 0.95rem;
    letter-spacing: normal;
    color: #1e293b;
}

.manual-base-wrapper {
    margin-top: 8px;
    transition: opacity 0.2s;
}

.action-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-top: 6px;
}

.btn {
    background: #ffffff;
    border: 1.5px solid #cbd5e1;
    padding: 12px 28px;
    border-radius: 40px;
    font-weight: 600;
    font-size: 1rem;
    color: #1e293b;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 2px 6px rgba(0,0,0,0.02);
    background: #f8fafc;
}

.btn-primary {
    background: #1e293b;
    border-color: #1e293b;
    color: white;
    box-shadow: 0 8px 16px -6px rgba(30, 41, 59, 0.2);
}

.btn-primary:hover {
    background: #0f172a;
    border-color: #0f172a;
}

.btn-outline:hover {
    background: #eef2ff;
    border-color: #3b82f6;
}

.base-indicator {
    background: #e6edfb;
    padding: 8px 18px;
    border-radius: 40px;
    font-size: 0.9rem;
    color: #1e4bd2;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.result-table-wrapper {
    overflow-x: auto;
    margin: 22px 0 16px;
    border-radius: 20px;
    border: 1px solid #eef2f6;
    background: white;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    min-width: 680px;
}

th {
    text-align: left;
    padding: 16px 16px 12px;
    background: #f8fafd;
    font-weight: 600;
    color: #334155;
    border-bottom: 2px solid #e2e8f0;
    font-size: 0.85rem;
}

td {
    padding: 14px 16px;
    border-bottom: 1px solid #ecf1f7;
    color: #1e293b;
}

tbody tr:last-child td {
    border-bottom: none;
}

.highlight-row {
    background: #faf9fe;
    font-weight: 600;
}

.summary-bar {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    background: #1e293b;
    color: white;
    padding: 18px 22px;
    border-radius: 28px;
    margin-top: 16px;
}

.summary-item {
    display: flex;
    flex-direction: column;
}

.summary-label {
    font-size: 0.8rem;
    opacity: 0.75;
    letter-spacing: 0.3px;
}

.summary-value {
    font-size: 1.8rem;
    font-weight: 700;
    line-height: 1.2;
}

.small-note {
    color: #94a3b8;
    font-size: 0.8rem;
    margin-top: 12px;
    text-align: right;
}

.disclaimer {
    background: #fff8e5;
    padding: 12px 18px;
    border-radius: 18px;
    font-size: 0.8rem;
    color: #92400e;
    margin-top: 18px;
    border-left: 4px solid #f59e0b;
}

.inline-flex {
    display: flex;
    align-items: center;
    gap: 8px;
}