* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Cascadia Code', 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
}
.top-links {
    width: 100%;
    padding: 0.5rem 2rem;
    text-align: right;
    background: transparent;
}
.top-links a {
    color: inherit;
    text-decoration: none;
    margin-left: 0.75rem;
    border-bottom: 1px solid transparent;
}
.top-links a:hover {
    border-bottom-color: #aaa;
}
.header {
    position: relative;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 0 2rem;
    margin-bottom: -300px;
}
.header-background {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 800px;
    height: 100%;
    object-fit: cover;
    z-index: 0;
    pointer-events: none;
    filter: blur(1.3px);
    border-radius: 0;
    opacity: 0.5;
}
.content {
    position: relative;
    z-index: 10;
    max-width: 800px;
    margin: 0 auto;
    padding: 100px 2rem 3rem 2rem;
    background: transparent;
    cursor: default;
}
.section {
    margin-bottom: 1rem;
    background: transparent;
    padding: 1rem;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #222;
}
h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #222;
}
p {
    font-size: 1.1rem;
    color: #333;
    line-height: 1.8;
    margin-bottom: 0.5rem;
}
a {
    color: #666;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s ease;
}
a:hover {
    border-bottom-color: #aaa;
}
blockquote {
    border-left: 4px solid #ccc;
    padding-left: 1rem;
    margin: 1rem 0;
    color: #555;
    font-style: normal;
    background-color: #f9f9f9;
}
.books-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-top: 1.5rem;
}
.book-card {
    border: 1px solid #e0e0e0;
    padding: 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    text-decoration: none;
    color: inherit;
    transition: border-color 0.3s ease;
}
.book-card:hover {
    border-color: #999;
}
.book-cover {
    width: 100px;
    height: 150px;
    object-fit: cover;
    flex-shrink: 0;
}
.book-info {
    flex: 1;
}
.book-title {
    font-size: 1.1rem;
    font-weight: normal;
    color: #222;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}
.book-author {
    font-size: 1rem;
    color: #666;
}
.grid-2x2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 两列 */
    grid-gap: 20px;
    max-width: 600px; /* 网格最大宽度 */
    margin: 0 auto;   /* 居中整个网格 */
}
.grid-2x2 > div {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9; /* 16:9比例 */
    overflow: hidden;      /* 超出部分裁剪 */
}
.grid-2x2 > div img {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 100%;
    object-fit: cover;     /* 图片填充并裁剪 */
    transform: translate(-50%, -50%); /* 居中裁剪 */
}
.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}
.section-header h2 {
    margin: 0;
}
.section-title-logo {
    height: 1.4em; /* 稍微增大 logo，使其更明显 */
    width: auto;
    display: inline-block;
}
@media (max-width: 768px) {
    .header {
        height: 300px;
    }
    .header-title {
        font-size: 1.8rem;
    }
    .header-text {
        font-size: 0.9rem;
    }
    h2 {
        font-size: 1.5rem;
    }
    p {
        font-size: 1rem;
    }
    .books-grid {
        grid-template-columns: 1fr;
    }
    .section-title-logo {
        height: 1em; /* 小屏幕时收起 logo，避免遮挡 */
    }
}
@media (min-width: 800px) {
    .header-background {
        top: 75px;
    }
}

/* Avatar row: two circular images side-by-side, gap 20px, max width 600px, left aligned */
#avatar .avatar-row {
    display: flex;
    gap: 20px;
    max-width: 400px;
    align-items: center;
    justify-content: flex-start; /* 左对齐 */
    margin: 0 auto;
}
#avatar .avatar-row img {
    width: calc(50% - 10px); /* 两张图各占一半，考虑间距 */
    aspect-ratio: 1 / 1;
    height: auto;
    object-fit: cover;
    border-radius: 50%;
    display: block;
}
@media (max-width: 480px) {
    #avatar .avatar-row {
        gap: 12px;
    }
    #avatar .avatar-row img {
        width: 120px;
    }
}