/* Page Load Animation - S Letter Expansion */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 99999;
    background: #0f1f2f;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.loader-content {
    position: relative;
    z-index: 3;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    animation: contentFadeIn 0.6s ease-out forwards;
}

.loader-letter {
    font-size: 35vw;
    font-weight: 900;
    color: transparent;
    -webkit-text-stroke: 3px rgba(255, 255, 255, 0.9);
    font-family: "Raleway", "Microsoft YaHei", sans-serif;
    line-height: 1;
    user-select: none;
    pointer-events: none;
    position: relative;
    filter: drop-shadow(0 0 20px rgba(255, 255, 255, 0.3));
}

.loader-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.5vw;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.95);
    font-family: "Raleway", "Microsoft YaHei", sans-serif;
    letter-spacing: 0.15em;
    white-space: nowrap;
    text-transform: uppercase;
    opacity: 0;
    animation: textFadeIn 0.5s ease-out 0.3s forwards;
}

@keyframes contentFadeIn {
    0% {
        opacity: 0;
        transform: scale(0.9);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes textFadeIn {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

.loader-mask {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #0f1f2f;
    z-index: 1;
    /* 使用SVG创建S字母形状的mask - 白色区域显示遮罩，黑色区域透明 */
    /* S字母部分填充黑色（透明），背景填充白色（遮罩） */
    -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 200'%3E%3Cdefs%3E%3Cmask id='sMask'%3E%3Crect width='100%25' height='100%25' fill='white'/%3E%3Ctext x='50%25' y='50%25' font-size='140' font-weight='900' font-family='Arial, sans-serif' text-anchor='middle' dominant-baseline='central' fill='black'%3ES%3C/text%3E%3C/mask%3E%3C/defs%3E%3Crect width='100%25' height='100%25' mask='url(%23sMask)' fill='white'/%3E%3C/svg%3E");
    mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 200'%3E%3Cdefs%3E%3Cmask id='sMask'%3E%3Crect width='100%25' height='100%25' fill='white'/%3E%3Ctext x='50%25' y='50%25' font-size='140' font-weight='900' font-family='Arial, sans-serif' text-anchor='middle' dominant-baseline='central' fill='black'%3ES%3C/text%3E%3C/mask%3E%3C/defs%3E%3Crect width='100%25' height='100%25' mask='url(%23sMask)' fill='white'/%3E%3C/svg%3E");
    -webkit-mask-size: 15% 20%;
    mask-size: 15% 20%;
    -webkit-mask-position: center;
    mask-position: center;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    animation: expandFromS 2s cubic-bezier(0.4, 0, 0.2, 1) 0.6s forwards;
}

@keyframes expandFromS {
    0% {
        -webkit-mask-size: 15% 20%;
        mask-size: 15% 20%;
        opacity: 1;
    }
    100% {
        -webkit-mask-size: 350% 350%;
        mask-size: 350% 350%;
        opacity: 0;
    }
}

/* 页面内容正常显示，但被遮罩层覆盖 */
body.page-loading {
    overflow: hidden;
}

body.page-loading main,
body.page-loading header,
body.page-loading footer {
    opacity: 1;
}

.page-loader.hidden {
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease-out, visibility 0.5s ease-out;
}

/* 移动端优化 */
@media (max-width: 768px) {
    .loader-letter {
        font-size: 45vw;
        -webkit-text-stroke: 2px rgba(255, 255, 255, 0.9);
    }
    
    .loader-text {
        font-size: 3vw;
        letter-spacing: 0.1em;
    }
    
    .loader-mask {
        -webkit-mask-size: 20% 25%;
        mask-size: 20% 25%;
    }
    
    @keyframes expandFromS {
        0% {
            -webkit-mask-size: 20% 25%;
            mask-size: 20% 25%;
            opacity: 1;
        }
        100% {
            -webkit-mask-size: 450% 450%;
            mask-size: 450% 450%;
            opacity: 0;
        }
    }
}