:root {
    --primary: #e74c3c;
    --secondary: #3498db;
    --danger: #c0392b;
    --light: #f9f9f9;
    --gray: #95a5a6;
    --success: #27ae60;
}

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

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: linear-gradient(135deg, var(--primary), var(--danger));
    border-radius: 10px;
    color: white;
    box-shadow: 0 4px 15px rgba(231, 76, 60, 0.2);
}

h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 25px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-3px);
}

h2 {
    color: var(--primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid #f0f0f0;
    font-size: 1.6rem;
}

h3 {
    color: var(--secondary);
    margin: 15px 0 10px;
}

label {
    display: block;
    margin: 15px 0 5px;
    font-weight: bold;
    color: #555;
}

input, select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
    transition: border 0.3s;
}

input:focus, select:focus {
    border-color: var(--secondary);
    outline: none;
    box-shadow: 0 0 5px rgba(52, 152, 219, 0.3);
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    margin-top: 15px;
    transition: background 0.3s;
    display: inline-block;
}

button:hover {
    background: var(--danger);
}

.btn-secondary {
    background: var(--secondary);
    margin-left: 10px;
}

.btn-secondary:hover {
    background: #2980b9;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

th {
    background-color: #f8f9fa;
    font-weight: bold;
    color: #444;
}

tr:hover {
    background-color: #f5f9ff;
}

.warning {
    color: var(--danger);
    font-weight: bold;
    padding: 15px;
    background: #ffecec;
    border-radius: 6px;
    margin-top: 20px;
    border-left: 4px solid var(--danger);
}

.note {
    font-size: 0.9em;
    color: var(--gray);
    margin-top: 5px;
    font-style: italic;
}

.flex-row {
    display: flex;
    gap: 15px;
}

.flex-row > div {
    flex: 1;
}

.asset-row {
    background: #f8fafc;
    margin: 10px 0;
    padding: 15px;
    border-radius: 8px;
    border-left: 3px solid var(--secondary);
}

.remove-asset {
    background: #e74c3c;
    color: white;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    margin-top: 10px;
}

#assetsContainer {
    margin: 20px 0;
}

#depreciationSummary {
    background: #e8f4ff;
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
}

.explanation {
    font-size: 0.85rem;
    color: #666;
    margin-top: 5px;
    line-height: 1.4;
}

.health-status {
    font-weight: bold;
    font-size: 1.1rem;
}

.status-healthy {
    color: var(--success);
}

.status-warning {
    color: #f39c12;
}

.status-danger {
    color: var(--danger);
}

.result-section {
    display: none;
}

.summary-box {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    margin: 15px 0;
}