/* ==========================================================================
   rail · 页面外壳（头部 / 页脚 / 主题 / 基础排版）
   仅新建的独立工具页引用，不覆盖站内既有样式。
   ========================================================================== */

:root {
    color-scheme: light;
    --rl-bg: #f5f2ec;
    --rl-bg-2: #efeae0;
    --rl-card: #fffdf8;
    --rl-card-2: #faf6ed;
    --rl-ink: #15181c;
    --rl-ink-2: #414a54;
    --rl-ink-3: #6c7681;
    --rl-line: #e3dccd;
    --rl-line-2: #cec3b0;
    --rl-accent: #bf3a2b;
    --rl-accent-rgb: 191, 58, 43;
    --rl-accent-ink: #fffdf8;
    --rl-teal: #0f766e;
    --rl-amber: #b4761d;
    --rl-board: #12181e;
    --rl-board-ink: #f3efe4;
    --rl-board-dim: #98a4af;
    --rl-board-amber: #ffc46b;
    --rl-ok: #16724f;
    --rl-warn: #9a5712;
    --rl-bad: #ad2a20;
    --rl-r: 14px;
    --rl-r-sm: 9px;
    --rl-wrap: 1200px;
    --rl-sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei UI", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
    --rl-mono: "Bahnschrift", "DIN Alternate", ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Mono", Consolas, monospace;
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --rl-bg: #0b0f13;
    --rl-bg-2: #0f141a;
    --rl-card: #121920;
    --rl-card-2: #161e26;
    --rl-ink: #eef2f5;
    --rl-ink-2: #b3bec8;
    --rl-ink-3: #8d9aa6;
    --rl-line: #232d37;
    --rl-line-2: #33404d;
    --rl-accent: #ff6a55;
    --rl-accent-rgb: 255, 106, 85;
    --rl-accent-ink: #1a0d0a;
    --rl-teal: #4ecdb4;
    --rl-amber: #f0b26b;
    --rl-board: #070a0d;
    --rl-board-ink: #f0f4f8;
    --rl-board-dim: #8d9aa6;
    --rl-board-amber: #ffcb7d;
    --rl-ok: #4ecdb4;
    --rl-warn: #f0b26b;
    --rl-bad: #ff8a80;
}

*,
*::before,
*::after { box-sizing: border-box; }

[hidden] { display: none !important; }

html {
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
    scroll-padding-top: 78px;
}

body {
    margin: 0;
    font-family: var(--rl-sans);
    font-size: 15.5px;
    line-height: 1.75;
    color: var(--rl-ink);
    background: var(--rl-bg);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    background:
        radial-gradient(900px 420px at 8% -12%, rgba(var(--rl-accent-rgb), .09), transparent 70%),
        radial-gradient(760px 360px at 96% 4%, rgba(15, 118, 110, .07), transparent 72%);
}

:root[data-theme="dark"] body::before {
    background:
        radial-gradient(900px 420px at 8% -12%, rgba(var(--rl-accent-rgb), .13), transparent 70%),
        radial-gradient(760px 360px at 96% 4%, rgba(78, 205, 180, .1), transparent 72%);
}

/* 排版基线只作用于本系列页面内容区（.rl-main），
   避免影响站点标准头部与页脚的字体、链接配色 */
.rl-main h1, .rl-main h2, .rl-main h3, .rl-main h4 { margin: 0; line-height: 1.3; font-weight: 700; letter-spacing: -.015em; }
.rl-main p { margin: 0; }
.rl-main a { color: var(--rl-accent); text-decoration: none; }
.rl-main a:hover { text-decoration: underline; text-underline-offset: 3px; }
.rl-main b, .rl-main strong { font-weight: 650; }
.rl-main img { max-width: 100%; height: auto; }
.rl-main button, .rl-main input, .rl-main select, .rl-main textarea { font: inherit; color: inherit; }
.rl-main button { cursor: pointer; }
.rl-main ::selection { background: rgba(var(--rl-accent-rgb), .22); }

:focus-visible {
    outline: 2px solid rgba(var(--rl-accent-rgb), .7);
    outline-offset: 2px;
    border-radius: 3px;
}

.rl-skip {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 100;
    background: var(--rl-accent);
    color: var(--rl-accent-ink);
    padding: 10px 16px;
    border-radius: 0 0 8px 0;
}
.rl-skip:focus { left: 0; }

.rl-wrap {
    width: 100%;
    max-width: var(--rl-wrap);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 头部 ---------- */
.rl-header {
    position: sticky;
    top: 0;
    z-index: 60;
    background: color-mix(in srgb, var(--rl-bg) 97%, transparent);
    border-bottom: 1px solid var(--rl-line);
    backdrop-filter: saturate(150%) blur(14px);
    -webkit-backdrop-filter: saturate(150%) blur(14px);
}
@supports not (background: color-mix(in srgb, red 50%, transparent)) {
    .rl-header { background: var(--rl-bg); }
}

.rl-header-in {
    display: flex;
    align-items: center;
    gap: 22px;
    min-height: 62px;
}

.rl-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--rl-ink);
    text-decoration: none;
    flex: none;
}
.rl-brand:hover { text-decoration: none; }

.rl-brand-mark {
    width: 32px;
    height: 32px;
    flex: none;
    display: grid;
    place-items: center;
    border: 1px solid rgba(var(--rl-accent-rgb), .42);
    border-radius: 9px;
    color: var(--rl-accent);
    background: rgba(var(--rl-accent-rgb), .08);
}

.rl-brand-text { display: grid; line-height: 1.15; }
.rl-brand-text b { font-size: 15px; letter-spacing: -.01em; }
.rl-brand-text i {
    font-style: normal;
    font-size: 10.5px;
    letter-spacing: .12em;
    color: var(--rl-ink-3);
}

.rl-nav {
    display: flex;
    align-items: center;
    gap: 2px;
    margin-left: auto;
}
.rl-nav a {
    padding: 7px 10px;
    border-radius: 7px;
    font-size: 13.5px;
    color: var(--rl-ink-2);
    text-decoration: none;
    white-space: nowrap;
}
.rl-nav a:hover { background: var(--rl-bg-2); color: var(--rl-ink); }

.rl-theme {
    display: inline-flex;
    padding: 2px;
    gap: 1px;
    border: 1px solid var(--rl-line-2);
    border-radius: 9px;
    background: var(--rl-card);
    flex: none;
}
.rl-theme button {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    border: 0;
    background: transparent;
    color: var(--rl-ink-3);
    font-size: 11.5px;
    line-height: 1;
    padding: 7px 8px;
    border-radius: 7px;
    transition: background .16s ease, color .16s ease;
}
.rl-theme button:hover { color: var(--rl-ink); }
.rl-theme button[aria-pressed="true"] {
    background: rgba(var(--rl-accent-rgb), .13);
    color: var(--rl-accent);
    font-weight: 650;
}

/* ---------- 页脚 ---------- */
.rl-foot {
    margin-top: 56px;
    border-top: 1px solid var(--rl-line);
    background: var(--rl-card-2);
    padding: 38px 0 26px;
    font-size: 13px;
    color: var(--rl-ink-3);
}
.rl-foot-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, .7fr));
    gap: 26px;
}
.rl-foot-brand p { margin-top: 12px; max-width: 34em; line-height: 1.8; }
.rl-foot-col { display: grid; gap: 6px; align-content: start; }
.rl-foot-col h2 {
    font-size: 12px;
    letter-spacing: .12em;
    color: var(--rl-ink-3);
    font-weight: 600;
    margin-bottom: 4px;
}
.rl-foot-col a { color: var(--rl-ink-2); font-size: 13px; width: fit-content; }
.rl-foot-col a:hover { color: var(--rl-accent); }

.rl-foot-bottom {
    margin-top: 28px;
    padding-top: 16px;
    border-top: 1px dashed var(--rl-line);
    display: grid;
    gap: 6px;
    font-size: 12px;
    line-height: 1.75;
}
.rl-foot-bottom a { color: var(--rl-ink-3); text-decoration: underline; text-underline-offset: 2px; }
.rl-foot-copy { color: var(--rl-ink-3); }

/* ---------- 通用按钮 ---------- */
.rl-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    height: 42px;
    padding: 0 18px;
    border-radius: var(--rl-r-sm);
    border: 1px solid var(--rl-line-2);
    background: var(--rl-card);
    color: var(--rl-ink);
    font-size: 14px;
    font-weight: 600;
    text-decoration: none;
    transition: border-color .16s ease, background .16s ease, transform .16s ease, color .16s ease;
    white-space: nowrap;
}
.rl-btn:hover { text-decoration: none; border-color: var(--rl-accent); color: var(--rl-accent); }
.rl-btn:active { transform: translateY(1px); }
.rl-btn--primary {
    background: var(--rl-accent);
    border-color: var(--rl-accent);
    color: var(--rl-accent-ink);
}
.rl-btn--primary:hover { color: var(--rl-accent-ink); background: color-mix(in srgb, var(--rl-accent) 88%, #000); border-color: transparent; }
.rl-btn--ghost { background: transparent; }
.rl-btn--sm { height: 34px; padding: 0 12px; font-size: 12.5px; }
.rl-btn[disabled] { opacity: .55; cursor: not-allowed; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
    .rl-nav a { padding: 7px 7px; font-size: 13px; }
    .rl-foot-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

@media (max-width: 860px) {
    .rl-nav { display: none; }
    .rl-theme { margin-left: auto; }
    .rl-theme button span { display: none; }
    .rl-theme button { padding: 8px; }
}

@media (max-width: 640px) {
    .rl-wrap { padding: 0 16px; }
    .rl-header-in { min-height: 56px; gap: 12px; }
    .rl-brand-mark { width: 29px; height: 29px; }
    .rl-brand-text i { display: none; }
    .rl-foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
    .rl-foot-brand { grid-column: 1 / -1; }
    .rl-btn { height: 40px; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition: none !important; animation: none !important; }
}

@media print {
    body { background: #fff; }
    .rl-header, .rl-foot, .rl-skip { display: none !important; }
}