/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础样式 */
body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #2D3748;
    background-color: #FFFFFF;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 顶部导航样式 */
.header {
    background-color: #FFFFFF;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 20px;
}

.logo {
    height: 50px;
    width: auto;
}

.nav-title {
    font-size: 28px;
    font-weight: 700;
    color: #2D3748;
    margin: 0;
}

/* 主要内容区域 */
.main {
    padding: 40px 0;
}

/* 说明文字样式 */
.note {
    text-align: center;
    margin-bottom: 40px;
}

.note p {
    font-size: 14px;
    color: #718096;
    font-style: italic;
}

/* 讲师列表样式 */
.instructors-list {
    display: flex;
    flex-direction: column;
    gap: 0;
}

/* 讲师卡片样式 */
.instructor-card {
    background-color: #FDFDFD;
    padding: 50px 0;
    border-bottom: 1px solid #E2E8F0;
    width: 100%;
}

.instructor-card.alternate {
    background-color: #FDFDFD;
}

.instructor-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 60px;
    display: flex;
    align-items: flex-start;
    gap: 60px;
}

/* 讲师头像样式 */
.instructor-avatar {
    flex-shrink: 0;
    width: 280px;
    max-width: 280px;
}

.avatar-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #4A90E2 0%, #357ABD 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #FFFFFF;
    font-size: 28px;
    font-weight: 600;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    position: relative;
    overflow: hidden;
}

.avatar-placeholder::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
}

/* 讲师真实照片样式 */
.instructor-photo {
    width: 100%;
    height: auto;
    object-fit: contain;
    border-radius: 0;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.instructor-photo:hover {
    transform: scale(1.02);
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.15);
}

/* 讲师信息样式 */
.instructor-info {
    flex: 1;
    padding-top: 10px;
}

.instructor-name {
    font-size: 36px;
    font-weight: 700;
    color: #2D3748;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
}

.instructor-title {
    font-size: 16px;
    font-weight: 600;
    color: #4A5568;
    margin-bottom: 16px;
}

.instructor-description {
    font-size: 18px;
    line-height: 1.7;
    color: #4A5568;
    text-align: justify;
    font-weight: 400;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .logo-section {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .nav-title {
        font-size: 24px;
    }
    
    .instructor-content {
        flex-direction: column;
        padding: 0 20px;
        gap: 20px;
        text-align: center;
    }
    
    .instructor-avatar {
        width: 150px;
        max-width: 150px;
        margin: 0 auto;
    }
    
    .avatar-placeholder {
        font-size: 20px;
    }
    
    .instructor-name {
        font-size: 28px;
    }
    
    .instructor-description {
        text-align: left;
    }
}

@media (max-width: 480px) {
    .nav-title {
        font-size: 20px;
    }
    
    .instructor-avatar {
        width: 120px;
        max-width: 120px;
    }
    
    .avatar-placeholder {
        font-size: 16px;
    }
    
    .instructor-name {
        font-size: 24px;
    }
    
    .instructor-title {
        font-size: 14px;
    }
    
    .instructor-description {
        font-size: 14px;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 选择文本样式 */
::selection {
    background-color: #667eea;
    color: #FFFFFF;
}

/* 焦点样式 */
:focus {
    outline: 2px solid #667eea;
    outline-offset: 2px;
}