/* --- Header --- */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 80px;
    padding: 0 24px;
    display: flex;
    /* justify-content: space-between; */
    align-items: center;
    z-index: 9999;
    pointer-events: none;
}

/* .logo {
    font-weight: 800;
    font-size: 24px;
    letter-spacing: -1px;
    pointer-events: auto;
    mix-blend-mode: difference;
    text-decoration: none;
    color: #FFF;
} */

/* --- Menu Button (Redesigned) --- */
.menu-btn {
    pointer-events: auto;
    position:absolute;
    right: 24px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: #FFFFFF;
    border: none;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    z-index: 1001;
    transition: background-color 0.4s ease, transform 0.2s ease, box-shadow 0.3s ease;
    /* 去掉默认高亮 */
    -webkit-tap-highlight-color: transparent;
}

.menu-btn:hover {
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.5);
    transform: scale(1.05);
}

.menu-btn:active {
    transform: scale(0.95);
}

/* 内部容器：负责整体旋转动画 */
.btn-inner {
    position: relative;
    width: 22px;
    height: 22px;
    transition: transform 0.5s cubic-bezier(0.68, -0.6, 0.32, 1.6);
    /* Q弹效果 */
}

/* Hover时，内部小球整体旋转 */
.menu-btn:hover .btn-inner {
    transform: rotate(90deg);
}

/* 4个小气泡/线条 */
.menu-btn span {
    position: absolute;
    display: block;
    background-color: #000;
    border-radius: 50%;
    /* 圆点 */
    width: 6px;
    height: 6px;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    /* 更有弹性的过渡 */
}

/* 初始位置：2x2 矩阵 */
.menu-btn span:nth-child(1) {
    top: 0;
    left: 0;
}

.menu-btn span:nth-child(2) {
    top: 0;
    right: 0;
}

.menu-btn span:nth-child(3) {
    bottom: 0;
    left: 0;
}

.menu-btn span:nth-child(4) {
    bottom: 0;
    right: 0;
}

/* --- Menu Open State (Morphing) --- */

.menu-btn.open {
    background: #FF3B30;
    /* 警告色背景 */
}

.menu-btn.open span {
    background-color: #FFF;
    border-radius: 2px;
    /* 变成圆角矩形线条 */
}

/* 变形逻辑：
           1和4 (左上/右下) -> 移动到中心 -> 变成第一条斜线 (/)
           2和3 (右上/左下) -> 移动到中心 -> 变成第二条斜线 (\)
        */
.menu-btn.open span:nth-child(1),
.menu-btn.open span:nth-child(4) {
    top: 50%;
    left: 50%;
    width: 24px;
    height: 2px;
    transform: translate(-50%, -50%) rotate(45deg);
}

.menu-btn.open span:nth-child(2),
.menu-btn.open span:nth-child(3) {
    top: 50%;
    left: 50%;
    width: 24px;
    height: 2px;
    transform: translate(-50%, -50%) rotate(-45deg);
}

/* 当菜单打开时，hover不再旋转，而是微微放大，防止视觉混乱 */
.menu-btn.open:hover .btn-inner {
    transform: rotate(0deg) scale(1.1);
}

/* --- Main Content (Behind Menu) --- */
.content-layer {
    text-align: center;
    z-index: 1;
    opacity: 1;
    transition: opacity 0.5s ease, transform 0.5s ease;
    padding: 20px;
    max-width: 800px;
}

body.menu-open .content-layer {
    opacity: 0.3;
    transform: scale(0.95);
    filter: blur(2px);
}

h1 {
    font-size: 4rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #fff, #aaa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -2px;
}

h2 {
    font-size: 1.5rem;
    font-weight: 300;
    color: #888;
    margin-bottom: 2rem;
    letter-spacing: 2px;
    text-transform: uppercase;
}

p.intro {
    font-size: 1.1rem;
    line-height: 1.6;
    color: #bbb;
    max-width: 600px;
    margin: 0 auto;
}

/* --- Canvas/Bubble Container --- */
#bubble-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 900;
    pointer-events: none;
}

#bubble-container.active {
    pointer-events: auto;
    background: rgba(15, 15, 18, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: background 0.5s ease;
}

.bubble {
    position: absolute;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    font-weight: 700;
    cursor: pointer;
    user-select: none;
    will-change: transform;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

.bubble:hover {
    box-shadow: 0 20px 50px rgba(255, 255, 255, 0.5);
    z-index: 910;
    filter:brightness(1.2)
}

.bubble:active {
    filter:brightness(1.6);
    transition: all 0.35s ease;
}

.bubble span {
    pointer-events: none;
    line-height: 1;
    text-transform: uppercase;
    transition: opacity 0.2s;
}

/* Mobile Typography */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 1rem;
    }
}



        ruby {
            ruby-position: over; 
        }
        rt {
            font-size: 0.5em; 
            color: #d63384; /* 给注音加个颜色区分 */
        }