/* 基础样式 */
:root {
    --primary-color: #4285f4;
    --dark-color: #333;
    --light-color: #f8f9fa;
    --border-color: #ddd;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.btn {
    display: inline-block;
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    font-size: 16px;
    transition: background 0.3s;
}

.btn:hover {
    background: #3367d6;
}

.card {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow: hidden;
}

.form-group {
    margin-bottom: 15px;
}

.form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
}

.alert {
    padding: 10px 15px;
    margin-bottom: 15px;
    border-radius: 4px;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
}

.alert-danger {
    background-color: #f8d7da;
    color: #721c24;
}

header {
    background-color: white;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    padding: 15px 0;
    margin-bottom: 30px;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 20px;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark-color);
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--primary-color);
}

footer {
    margin-top: 50px;
    padding: 20px 0;
    text-align: center;
    color: #666;
    border-top: 1px solid var(--border-color);
}