/* ==========================================================================
   首屏加载屏
   --------------------------------------------------------------------------
   全站共用（每个页面 <head> 里引这一份，<body> 开头放一个空的
   `<div class="boot" id="boot">`，内容与逻辑由 assets/js/boot.js 生成）。
   何时显示由各页 <head> 里那段内联脚本同步决定：给 <html> 挂上 sss-boot
   才显示 —— 必须在首次绘制前决定，否则会先画出页面再盖上，闪一下。
   ========================================================================== */

.boot { display: none; }
html.sss-boot .boot {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 99999;
}

/* 背景里那枚放大的、半透明的 logo。
   它和读数一起在开门前先淡掉 —— 不留到舱门展开的时候，那样会显得退得太晚。 */
.boot__bg {
    position: absolute;
    left: 50%;
    top: 50%;
    width: min(78vh, 72vw);
    height: min(78vh, 72vw);
    transform: translate(-50%, -50%);
    background-color: rgba(255, 255, 255, 0.07);
    -webkit-mask: url("../img/logo_SSS.svg") center / contain no-repeat;
            mask: url("../img/logo_SSS.svg") center / contain no-repeat;
    pointer-events: none;
    opacity: 1;
    transition: opacity 0.22s ease;
}
.boot.is-open .boot__bg { opacity: 0; }

/* 简报框：一圈细描边 + 两个金色角标 */
.boot__frame {
    position: absolute;
    inset: 22px;
    border: 1px solid rgba(255, 255, 255, 0.07);
    pointer-events: none;
    transition: opacity 0.22s ease;
}
.boot.is-open .boot__frame { opacity: 0; }
.boot__frame::before,
.boot__frame::after {
    content: '';
    position: absolute;
    width: 18px;
    height: 18px;
    border: 1px solid rgba(255, 215, 0, 0.5);
}
.boot__frame::before { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.boot__frame::after { right: -1px; bottom: -1px; border-top: 0; border-left: 0; }

/* 上下两扇门：等中间那层（logo / 读数 / 框）先淡掉再开，0.2s 的错拍 */
.boot__half {
    position: absolute;
    left: 0;
    width: 100%;
    height: calc(50% + 1px);
    background: #05060b;
    transition: transform 0.8s cubic-bezier(0.76, 0, 0.24, 1) 0.2s;
}
.boot__half--top { top: 0; }
.boot__half--bottom { bottom: 0; }
.boot.is-open .boot__half--top { transform: translateY(-100%); }
.boot.is-open .boot__half--bottom { transform: translateY(100%); }

/* 中缝那道金线：开门瞬间淡掉 */
.boot__seam {
    position: absolute;
    left: 0;
    right: 0;
    top: calc(50% - 1px);
    height: 2px;
    background: linear-gradient(90deg, transparent, rgba(255, 215, 0, 0.85), transparent);
    opacity: 0.28;
    transition: opacity 0.3s;
}
.boot.is-open .boot__seam { opacity: 0; }

/* 中间读数：等宽，用系统等宽字体，不去等 Sarasa Mono（那正是它要等的资源） */
.boot__inner {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px;
    text-align: center;
    font-family: ui-monospace, "Cascadia Mono", Consolas, monospace;
    transition: opacity 0.26s ease, transform 0.26s ease;
}
.boot.is-open .boot__inner { opacity: 0; transform: scale(0.98); }

/* 去掉小 logo 后，标题直接顶在最上面 */
.boot__title { font-size: 19px; letter-spacing: 8px; color: #fff; }
.boot__sub {
    margin-top: 9px;
    font-size: 10px;
    letter-spacing: 3px;
    color: rgba(255, 255, 255, 0.32);
}

.boot__steps {
    display: flex;
    flex-direction: column;
    gap: 7px;
    margin-top: 32px;
}
.boot__step {
    display: flex;
    align-items: center;
    gap: 9px;
    font-size: 11px;
    letter-spacing: 1.5px;
    color: rgba(255, 255, 255, 0.3);
    transition: color 0.25s;
}
.boot__step i {
    width: 5px;
    height: 5px;
    flex: 0 0 auto;
    background: rgba(255, 255, 255, 0.18);
    transition: background 0.25s, box-shadow 0.25s;
}
.boot__step.is-done { color: rgba(255, 255, 255, 0.82); }
.boot__step.is-done i {
    background: #FFD700;
    box-shadow: 0 0 8px rgba(255, 215, 0, 0.8);
}

.boot__bar {
    width: min(320px, 62vw);
    height: 2px;
    margin-top: 26px;
    background: rgba(255, 255, 255, 0.12);
    overflow: hidden;
}
.boot__bar i {
    display: block;
    width: 0;
    height: 100%;
    background: #FFD700;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.boot__hint {
    margin-top: 16px;
    font-size: 10px;
    letter-spacing: 1px;
    color: rgba(255, 255, 255, 0.24);
}

/* 门开时，底下的页面从略微缩小恢复，像被"推近"了一点。
   注意只动 main —— body 上有 position:fixed 的背景层，给 body 加 transform 会把它们框住。 */
html.sss-boot main { transform: scale(0.992); opacity: 0.5; }
html.sss-boot.boot-open main {
    transform: none;
    opacity: 1;
    transition: transform 0.8s cubic-bezier(0.76, 0, 0.24, 1) 0.2s, opacity 0.6s ease 0.2s;
}

@media (prefers-reduced-motion: reduce) {
    .boot__half,
    .boot__inner,
    .boot__seam,
    html.sss-boot.boot-open main {
        transition-duration: 0.001s !important;
    }
}