/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
}

body {
    overflow: hidden; /* 防止滚动条出现 */
    height: 100vh;
    /* 您指定的流体渐变背景 */
    background: linear-gradient(120deg, #4a00e0, #8e2de2, #00c6ff, #0072ff);
    background-size: 400% 400%;
    animation: gradientMove 12s ease infinite;
    position: relative;
}

/* 动态渐变背景动画 */
@keyframes gradientMove {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* 粒子 canvas 层 */
#particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 1; /* 粒子在最底层，但在背景之上 */
    pointer-events: none; /* 确保粒子不阻挡鼠标点击 */
}

/* 内容容器 */
.container {
    position: relative;
    z-index: 2; /* 内容在粒子之上 */
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
    padding-bottom: 80px; /* 稍微向上提一点，留出底部空间 */
}

/* 主标题动画 */
.title {
    font-size: 60px;
    font-weight: bold;
    letter-spacing: 2px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.2); /* 增加一点阴影提升可读性 */
    animation: float 4s ease-in-out infinite;
}

/* 浮动动画 */
@keyframes float {
    0% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
    100% { transform: translateY(0); }
}

/* 副标题淡入动画 */
.subtitle {
    margin-top: 20px;
    font-size: 24px;
    font-weight: 300;
    opacity: 0;
    animation: fadeIn 2s forwards 0.5s; /* 稍微加快一点出现速度 */
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 炫酷发光按钮 */
.btn {
    margin-top: 50px;
    padding: 14px 45px;
    font-size: 18px;
    color: white;
    text-decoration: none;
    border-radius: 50px;
    /* 玻璃拟态效果 */
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 15px rgba(255,255,255,0.2);
    transition: all 0.35s ease;
    opacity: 0;
    animation: fadeIn 2s forwards 1s; /* 按钮最后出现 */
    cursor: pointer;
}

.btn:hover {
    background: rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 25px rgba(255,255,255,0.6);
    transform: scale(1.05) translateY(-2px);
}

/* 底部备案 + 版权 */
.footer {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    z-index: 3;
    color: rgba(255,255,255,0.85);
    font-size: 14px;
    line-height: 1.8;
    width: 100%;
}

.beian-line {
    margin-bottom: 5px;
}

.footer .beian {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    font-weight: 500;
    transition: 0.3s;
    border-bottom: 1px dashed rgba(255,255,255,0.4);
}

.footer .beian:hover {
    text-shadow: 0 0 8px rgba(255,255,255,0.9);
    color: #fff;
    border-bottom: 1px solid #fff;
}

.footer p {
    font-size: 12px;
    opacity: 0.7;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .title { font-size: 36px; }
    .subtitle { font-size: 18px; }
    .btn { padding: 12px 30px; font-size: 16px; }
}