:root {
    --bg-color: #1a1d24;
    --surface-color: #252a33;
    --primary-color: #00aaff;
    --text-color: #e0e0e0;
    --text-muted-color: #8a92a1;
    --border-color: #3a414d;
}

body, html {
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 16px;
}

/* Login Page */
.login-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(45deg, #1a1d24, #252a33);
}

.login-box {
    width: 400px;
    padding: 50px;
    background-color: var(--surface-color);
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.login-box h1 {
    color: #fff;
    margin-bottom: 10px;
}

.login-box p {
    color: var(--text-muted-color);
    margin-bottom: 30px;
}

.input-group {
    margin-bottom: 20px;
}

.input-group input {
    width: 100%;
    padding: 15px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    font-size: 1rem;
    box-sizing: border-box;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.input-group input::placeholder {
    color: var(--text-muted-color);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 170, 255, 0.2);
}

button {
    width: 100%;
    padding: 15px;
    border: none;
    border-radius: 8px;
    background-color: var(--primary-color);
    color: #fff;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}

button:hover {
    background-color: #0088cc;
}

button:active {
    transform: scale(0.98);
}

.error-message {
    color: #ff4d4d;
    margin-top: 20px;
    height: 22px;
    font-size: 0.9rem;
}

/* Main App Layout */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.app-header {
    display: flex;
    align-items: center;
    padding: 0 40px;
    height: 70px;
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.app-header .logo h2 {
    color: var(--primary-color);
    margin: 0;
}

.main-nav {
    margin: 0 auto;
    display: flex;
    gap: 20px;
}

.main-nav a {
    padding: 10px 20px;
    text-decoration: none;
    color: var(--text-muted-color);
    font-weight: 500;
    border-radius: 8px;
    transition: color 0.3s, background-color 0.3s;
}

.main-nav a:hover {
    color: var(--text-color);
    background-color: rgba(255,255,255,0.05);
}

.main-nav a.active {
    color: #fff;
    background-color: var(--primary-color);
}

#logout-btn {
    width: auto;
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-muted-color);
}

#logout-btn:hover {
    background-color: var(--border-color);
    color: var(--text-color);
}

.app-main {
    flex-grow: 1;
    padding: 40px;
    overflow-y: auto;
    height: calc(100vh - 70px); /* 减去 header 高度 */
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
}

.content-section.active {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.section-header h2 {
    font-size: 1.5rem;
    margin-top: 0;
    margin-bottom: 20px;
    color: #fff;
    flex-shrink: 0;
}

/* Dashboard */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 20px;
    flex-shrink: 0;
}

.stat-card {
    background-color: var(--surface-color);
    padding: 25px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.stat-card h4 {
    margin: 0 0 10px;
    color: var(--text-muted-color);
    font-size: 1rem;
    font-weight: 500;
}

.stat-card p {
    margin: 0;
    font-size: 2.5rem;
    font-weight: bold;
    color: #fff;
}

.content-section { display: none; }

.chart-wrapper {
    background-color: var(--surface-color);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    flex-grow: 1; /* 自动填充剩余空间 */
    margin-bottom: 50px; /* 距离底部 50px */
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.chart-wrapper h3 {
    margin: 0 0 20px;
    flex-shrink: 0;
}

.chart-inner-container {
    flex-grow: 1;
    position: relative; /* 核心修复：Chart.js 需要相对定位的父容器 */
    min-height: 0;
}

.chart-inner-container canvas {
    width: 100% !important;
    height: 100% !important;
}

.chart-wrapper h3 {
    margin-top: 0;
    margin-bottom: 20px;
}

/* Reports */
.filter-bar {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
}

.filter-bar input {
    padding: 12px 15px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    flex-grow: 1;
}

.filter-bar button {
    width: auto;
    padding: 0 25px;
}

.table-wrapper {
    background-color: var(--surface-color);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 18px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

thead th {
    background-color: rgba(0,0,0,0.2);
    font-weight: 600;
    color: var(--text-muted-color);
}

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

tbody tr:hover {
    background-color: rgba(255,255,255,0.03);
}

.pagination {
    margin-top: 30px;
    text-align: center;
}

.pagination button {
    width: auto;
    padding: 8px 16px;
    margin: 0 5px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
}

.pagination button:disabled {
    background-color: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

/* Account */
.account-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.form-container {
    background-color: var(--surface-color);
    padding: 40px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.form-container h3 {
    margin-top: 0;
    margin-bottom: 30px;
    color: #fff;
}

.form-row {
    margin-bottom: 20px;
    display: flex;
    align-items: center; /* 垂直居中对齐 */
}

.form-row label {
    width: 120px; /* 标签固定宽度，实现左侧对齐 */
    flex-shrink: 0;
    margin-bottom: 0; /* 移除下边距，实现左右排版 */
    color: var(--text-muted-color);
}

.form-row input, .form-row span {
    flex-grow: 1; /* 输入框占据剩余空间 */
    padding: 12px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    box-sizing: border-box;
}

.form-row span {
    padding: 12px;
    background-color: transparent;
    border: none;
    font-weight: bold;
}

.form-container button {
    margin-top: 10px;
}