/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 头部样式 */
.header {
    background: rgba(255, 255, 255, 0.95);
    padding: 1rem 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border-radius: 0 0 20px 20px;
    margin-bottom: 2rem;
}

.header h1 {
    color: #333;
    text-align: center;
    margin-bottom: 1rem;
}

.nav {
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #666;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: all 0.3s;
}

.nav-link:hover, .nav-link.active {
    background: #667eea;
    color: white;
}

/* 主内容区 */
.main-content {
    flex: 1;
    padding: 0 2rem;
}

/* 警告框 */
.alert {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
    margin-bottom: 2rem;
}

.alert-warning {
    border-left: 5px solid #ffc107;
}

.alert h3 {
    color: #333;
    margin-bottom: 1rem;
}

/* 欢迎区域 */
.welcome-section {
    background: white;
    padding: 3rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
}

.welcome-section h2 {
    color: #333;
    margin-bottom: 2rem;
}

.exam-info {
    text-align: left;
    max-width: 500px;
    margin: 0 auto 2rem;
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 10px;
}

.exam-info ul {
    margin-left: 1rem;
}

.exam-info li {
    margin-bottom: 0.5rem;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    background: #667eea;
    color: white;
    text-decoration: none;
    border-radius: 25px;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    transition: all 0.3s;
    margin: 0.5rem;
}

.btn:hover {
    background: #5a6fd8;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.btn-primary {
    background: #28a745;
}

.btn-primary:hover {
    background: #218838;
}

.btn-start {
    background: #dc3545;
    font-size: 1.2rem;
    padding: 1rem 3rem;
}

.btn-start:hover {
    background: #c82333;
}

/* 考试界面样式 */
.exam-container {
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    padding: 2rem;
    margin-bottom: 2rem;
}

.timer {
    background: #ffc107;
    color: #333;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: bold;
    margin-bottom: 2rem;
}

.question {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #eee;
}

.question h3 {
    color: #333;
    margin-bottom: 1rem;
}

.options {
    display: grid;
    gap: 0.5rem;
}

.option {
    padding: 1rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.option:hover {
    border-color: #667eea;
    background: #f8f9ff;
}

.option.selected {
    border-color: #667eea;
    background: #667eea;
    color: white;
}

/* 后台管理样式 */
.admin-container {
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    padding: 2rem;
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
    color: #333;
}

.form-control {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
}

.form-control:focus {
    border-color: #667eea;
    outline: none;
}

/* 结果页面 */
.result-section {
    text-align: center;
    padding: 3rem;
}

.result-score {
    font-size: 4rem;
    font-weight: bold;
    color: #dc3545;
    margin: 1rem 0;
}

.result-pass {
    color: #28a745;
}

.result-fail {
    color: #dc3545;
}

/* 页脚 */
.footer {
    text-align: center;
    padding: 2rem;
    color: white;
    margin-top: auto;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .header {
        padding: 1rem;
    }
    
    .nav {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .main-content {
        padding: 0;
    }
    
    .welcome-section, .exam-container, .admin-container {
        padding: 1.5rem;
    }
    
    .exam-info {
        padding: 1rem;
    }
    
    .btn {
        padding: 0.8rem 1.5rem;
        font-size: 1rem;
    }
    
    .timer {
        font-size: 1.2rem;
    }
    
    .result-score {
        font-size: 3rem;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.5rem;
    }
    
    .welcome-section h2 {
        font-size: 1.3rem;
    }
    
    .result-score {
        font-size: 2.5rem;
    }
}