body {
    margin: 0;
    font-family: "Arial", sans-serif;

    /* 背景图 */
    background-image: url("../blackboard/.jpg"); /* 图片地址 */
    background-size: cover;                  /* 自动缩放并裁剪 */
    background-position: center center;      /* 居中裁剪 */
    background-repeat: no-repeat;            /* 不重复平铺 */

    /* 铺满整个屏幕 */
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

.main-layout {
    display: flex;
    flex-direction: row;
    height: calc(100vh - 100px);
    padding-bottom: 100px;
}

.left-panel, .right-panel {
    width: 50%;
    display: flex;
    justify-content: center; /* 水平居中 */
    align-items: center;     /* 垂直居中 */
    flex-direction: column;  /* 内容垂直排列 */
    padding: 20px;
    box-sizing: border-box;
    height: 100%;
}

.logo {
    margin-top: 40px;
    font-size: 50px;
}

.intro a {
    display: block;
    margin: 5px 0;
}

.logo {
    font-family: 'Pacifico', cursive;
}

/* 默认隐藏 */
.mobile-toggle {
    display: none;
    margin: 10px;
    text-align: center;
}

/* 全屏按钮样式（仅大屏幕显示） */
#fullscreen-button {
    position: absolute;
    right: 12px;
    top: 7px;
    background: none;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: top 0.3s ease,transform 0.3s ease-in-out, padding 0.3s ease-in-out; /* 平滑放大动画 */
    transform-origin: center center; /* 确保放大时的中心不变 */
}

#fullscreen-button:hover {
    transform: scale(1.20); /* 悬停时上下左右均匀放大 20% */
}