/* =========================================================================
   百香集 · 本源识香 —— 公共样式
   仅由 本源识香 栏目内的 6 个页面引用（香源考 / 香材图鉴 / 等级甄选 /
   仓储藏香 / 香材炮制 / 古今异名）。
   目录：1.设计变量 2.基础重置 3.布局 4.顶部导航 5.移动端抽屉
        6.横幅 7.区块标题 8.通用组件 9.滚动显现 10.页脚
        11.进度与回到顶部 12.章节导航 13.灯箱 14.响应式
   ========================================================================= */

/* ---------- 1. 设计变量 ---------- */
:root {
    --paper: #F6EFE2;
    --paper-alt: #EFE4D0;
    --card: #FBF7EE;
    --nav: #ECE1CF;
    --ink: #3D3226;
    --ink-2: #6B5A47;
    --ink-3: #9A8B76;
    --line: #D8C9B4;
    --line-soft: #E4D8C4;
    --accent: #8C5A3A;
    --accent-2: #A63D2F;
    --gold: #B08D57;
    --cyan: #629492;

    --font-title: "SimSun", "Songti SC", "STSong", "Noto Serif SC", serif;
    --font-body: "Microsoft YaHei", "PingFang SC", "Microsoft YaHei UI", sans-serif;
    --font-deco: "KaiTi", "STKaiti", "KaiTi_GB2312", serif;

    --shadow-1: 0 2px 10px rgba(74, 58, 35, 0.06);
    --shadow-2: 0 10px 26px rgba(74, 58, 35, 0.10);
    --shadow-3: 0 20px 46px rgba(74, 58, 35, 0.16);
    --shadow-hover: 0 16px 38px rgba(74, 58, 35, 0.18);

    --r-sm: 2px;
    --r-md: 4px;
    --r-lg: 8px;
    --nav-h: 68px;
    --nav-h-sm: 58px;
    --ease: cubic-bezier(.22, .61, .36, 1);
    --ease-out: cubic-bezier(.16, 1, .3, 1);
}

/* ---------- 2. 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    padding-top: var(--nav-h);
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-body);
    font-size: 14px;
    line-height: 1.9;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

body.is-locked { overflow: hidden; }

h1, h2, h3, h4, p, figure, blockquote, dl, dd, ol, ul { margin: 0; }
ol, ul { padding: 0; list-style: none; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; }
em { font-style: normal; }

::selection { background: rgba(166, 61, 47, 0.16); color: var(--accent-2); }

/* ---------- 3. 布局 ---------- */
.site {
    max-width: 1920px;
    margin: 0 auto;
    background: var(--paper);
    position: relative;
}

.container {
    width: 100%;
    max-width: 1360px;
    margin: 0 auto;
    padding: 0 40px;
}

/* ---------- 4. 顶部导航 ---------- */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 200;
    background: #ECE1CF;
    border-bottom: 1px solid var(--line);
    transition: box-shadow .35s var(--ease), background .35s var(--ease);
}

/* 注意：此处不使用 backdrop-filter。
   filter / backdrop-filter 会成为 fixed 子元素的包含块，
   导致移动端抽屉与遮罩无法铺满视口。 */

.top-nav.is-scrolled {
    box-shadow: 0 8px 26px rgba(74, 58, 35, 0.10);
    background: rgba(240, 231, 216, 0.96);
}

.nav-wrap {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    max-width: 1360px;
    margin: 0 auto;
    padding: 0 40px;
    height: var(--nav-h);
    transition: height .35s var(--ease);
}

.top-nav.is-scrolled .nav-wrap { height: var(--nav-h-sm); }

.logo {
    display: flex;
    align-items: center;
    flex: 0 0 auto;
    transition: opacity .25s var(--ease), transform .25s var(--ease);
}

.logo:hover { opacity: .82; }
.logo img {
    height: 34px;
    width: auto;
    transition: height .35s var(--ease);
}
.top-nav.is-scrolled .logo img { height: 29px; }

nav[aria-label="主导航"] {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

.nav-main {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-item { position: relative; }

.nav-item > a {
    position: relative;
    display: flex;
    align-items: center;
    padding: 9px 20px;
    font-family: var(--font-title);
    font-size: 16px;
    letter-spacing: 3px;
    color: var(--ink);
    white-space: nowrap;
    transition: color .22s var(--ease);
}

.nav-item > a::before {
    content: "";
    position: absolute;
    left: 20px;
    right: 20px;
    bottom: 3px;
    height: 1px;
    background: var(--accent-2);
    transform: scaleX(0);
    transform-origin: left center;
    transition: transform .32s var(--ease);
}

.nav-item > a:hover,
.nav-item.current > a { color: var(--accent-2); }

.nav-item > a:hover::before,
.nav-item.current > a::before { transform: scaleX(1); }

/* 下拉小箭头 */
.nav-item.has-sub > a::after {
    content: "";
    width: 5px;
    height: 5px;
    margin-left: 9px;
    border-right: 1.4px solid currentColor;
    border-bottom: 1.4px solid currentColor;
    transform: translateY(-2px) rotate(45deg);
    opacity: .55;
    transition: transform .28s var(--ease), opacity .28s var(--ease);
}

.nav-item.has-sub:hover > a::after,
.nav-item.has-sub.is-open > a::after {
    transform: translateY(0) rotate(225deg);
    opacity: 1;
}

/* 二级菜单 */
.nav-sub {
    position: absolute;
    top: calc(100% + 10px);
    left: 50%;
    min-width: 168px;
    padding: 8px 0;
    background: var(--card);
    border: 1px solid var(--line);
    border-top: 2px solid var(--accent);
    box-shadow: var(--shadow-3);
    opacity: 0;
    visibility: hidden;
    transform: translate(-50%, 10px);
    transition: opacity .24s var(--ease), transform .24s var(--ease), visibility .24s;
    z-index: 60;
}

/* 悬停缓冲区，避免鼠标下移时菜单闪断 */
.nav-sub::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: -12px;
    height: 12px;
}

/* 防止误嵌套的空菜单（历史遗留结构） */
.nav-sub .nav-sub { display: none !important; }

.nav-item:hover .nav-sub,
.nav-item:focus-within .nav-sub,
.nav-item.is-open .nav-sub {
    opacity: 1;
    visibility: visible;
    transform: translate(-50%, 0);
}

.nav-sub li a {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 9px 16px;
    font-size: 13.5px;
    letter-spacing: 2px;
    color: var(--ink-2);
    white-space: nowrap;
    border-left: 2px solid transparent;
    transition: color .2s var(--ease), background .2s var(--ease),
                border-color .2s var(--ease);
}

.nav-sub li a:hover,
.nav-sub li a:focus-visible {
    color: var(--accent-2);
    background: var(--paper-alt);
    border-left-color: var(--accent-2);
}

.nav-sub li a.active {
    color: var(--accent-2);
    font-weight: 600;
    border-left-color: var(--accent-2);
    background: rgba(239, 228, 208, 0.55);
}

/* 汉堡按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: transparent;
    cursor: pointer;
    transition: border-color .25s var(--ease), background .25s var(--ease);
    z-index: 220;
}

.nav-toggle:hover { border-color: var(--accent); background: rgba(255, 255, 255, .4); }

.nav-toggle span {
    display: block;
    width: 20px;
    height: 1.6px;
    background: var(--ink);
    border-radius: 2px;
    transition: transform .3s var(--ease), opacity .2s var(--ease);
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.6px) rotate(-45deg); }

/* 遮罩 */
.nav-mask {
    position: fixed;
    inset: 0;
    z-index: 205;
    background: rgba(46, 36, 27, 0.44);
    backdrop-filter: blur(2px);
    opacity: 0;
    visibility: hidden;
    transition: opacity .35s var(--ease), visibility .35s;
}

/* ---------- 6. 横幅 ---------- */
.banner {
    position: relative;
    display: flex;
    align-items: center;
    min-height: clamp(380px, 44vw, 580px);
    overflow: hidden;
    isolation: isolate;
    background: var(--paper-alt);
}

.banner-bg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 72% center;
    animation: bannerZoom 14s var(--ease-out) both;
}

@keyframes bannerZoom {
    from { transform: scale(1.06); }
    to { transform: scale(1); }
}

.banner::before {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 1;
    background:
        linear-gradient(96deg, rgba(246, 239, 226, .96) 0%, rgba(246, 239, 226, .88) 24%,
        rgba(246, 239, 226, .42) 46%, rgba(246, 239, 226, 0) 64%),
        linear-gradient(0deg, rgba(246, 239, 226, .85) 0%, rgba(246, 239, 226, 0) 26%);
}

.banner-inner {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1360px;
    margin: 0 auto;
    padding: 40px;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 32px;
}

.banner-copy {
    padding-left: 34px;
    border-left: 1px solid rgba(140, 90, 58, 0.42);
    max-width: 620px;
}

.breadcrumb {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
    font-size: 12px;
    letter-spacing: 2px;
    color: var(--ink-3);
}

.breadcrumb a { transition: color .2s var(--ease); }
.breadcrumb a:hover { color: var(--accent-2); }
.breadcrumb span { opacity: .6; }
.breadcrumb em { color: var(--accent); }

.banner-copy h1 {
    font-family: var(--font-title);
    font-weight: 400;
    font-size: clamp(34px, 4vw, 54px);
    line-height: 1.18;
    letter-spacing: 12px;
    color: #5B3722;
    text-indent: 4px;
}

.banner-sub {
    margin-top: 14px;
    font-family: var(--font-deco);
    font-size: clamp(14px, 1.15vw, 17px);
    letter-spacing: 5px;
    color: var(--accent);
}

.banner-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-top: 26px;
}

.banner-seal {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    flex: 0 0 auto;
    background: var(--accent-2);
    border-radius: var(--r-sm);
    color: var(--paper);
    font-family: var(--font-deco);
    font-size: 21px;
    line-height: 1;
    transform: rotate(-5deg);
    box-shadow: 0 6px 14px rgba(166, 61, 47, 0.26);
}

.banner-rule {
    flex: 1;
    max-width: 190px;
    height: 1px;
    background: linear-gradient(90deg, rgba(140, 90, 58, .55), rgba(140, 90, 58, 0));
}

/* ---------- 7. 区块 ---------- */
.section { padding: 96px 0; position: relative; }
.section-alt { background: var(--paper-alt); }

.section-head {
    max-width: 760px;
    margin: 0 auto 54px;
    text-align: center;
}

.section-head h2 {
    position: relative;
    display: inline-block;
    padding: 0 58px;
    font-family: var(--font-title);
    font-weight: 400;
    font-size: clamp(26px, 2.5vw, 34px);
    line-height: 1.4;
    letter-spacing: 8px;
    color: var(--ink);
    text-indent: 8px;
}

.section-head h2::before,
.section-head h2::after {
    content: "";
    position: absolute;
    top: 50%;
    width: 40px;
    height: 1px;
    background: var(--accent);
    opacity: .5;
}

.section-head h2::before {
    left: 0;
    background: linear-gradient(90deg, rgba(140, 90, 58, 0), rgba(140, 90, 58, .85));
}

.section-head h2::after {
    right: 0;
    background: linear-gradient(270deg, rgba(140, 90, 58, 0), rgba(140, 90, 58, .85));
}

.section-head p {
    margin-top: 16px;
    font-family: var(--font-deco);
    font-size: 15px;
    letter-spacing: 3px;
    color: #7C6A55;
    line-height: 1.9;
}

.section-head.is-left { text-align: left; margin-left: 0; }
.section-head.is-left h2 { padding-left: 0; }
.section-head.is-left h2::before { display: none; }

/* ---------- 8. 通用组件 ---------- */
.lead {
    font-size: 16px;
    line-height: 2.05;
    color: var(--ink);
    letter-spacing: .5px;
}

.prose p {
    font-size: 14px;
    line-height: 2.1;
    color: var(--ink-2);
    text-align: justify;
}

.prose p + p { margin-top: 18px; }

.chip {
    display: inline-flex;
    align-items: center;
    padding: 3px 14px;
    font-size: 12.5px;
    letter-spacing: 1.5px;
    color: var(--accent);
    border: 1px solid rgba(140, 90, 58, .45);
    border-radius: 999px;
    background: rgba(251, 247, 238, .6);
    white-space: nowrap;
}

:focus-visible {
    outline: 2px solid var(--accent-2);
    outline-offset: 3px;
}

/* ---------- 9. 滚动显现 ---------- */
/* 说明：
   1) 只在 html.js 存在时隐藏内容，脚本失效时仍可正常阅读；
   2) 用 animation 而非 transition 实现，
      避免与卡片、按钮自带的 transition（hover 位移）互相覆盖。 */
.js .reveal { opacity: 0; }

.js .reveal.is-in {
    opacity: 1;
    animation: revealIn .85s var(--ease) var(--d, 0ms) 1 normal backwards;
}

@keyframes revealIn {
    from { opacity: 0; transform: translateY(26px); }
    to { opacity: 1; transform: none; }
}

/* ---------- 10. 页脚 ---------- */
footer {
    position: relative;
    padding: 52px 0 44px;
    border-top: 1px solid var(--line);
    background: var(--paper-alt);
    text-align: center;
}

.foot-inner {
    max-width: 1360px;
    margin: 0 auto;
    padding: 0 40px;
}

.foot-brand {
    display: inline-block;
    margin-bottom: 10px;
    font-family: var(--font-deco);
    font-size: 16px;
    letter-spacing: 6px;
    color: var(--ink-2);
}

.foot-brand::before,
.foot-brand::after {
    content: "·";
    margin: 0 12px;
    color: var(--accent);
}

footer p:last-child {
    font-size: 12px;
    letter-spacing: 1px;
    color: var(--ink-3);
}

/* ---------- 11. 进度 / 回到顶部 ---------- */
.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 260;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    transition: width .12s linear;
    pointer-events: none;
}

.to-top {
    position: fixed;
    right: 28px;
    bottom: 28px;
    z-index: 190;
    width: 46px;
    height: 46px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    background: var(--card);
    color: var(--accent);
    border: 1px solid var(--line);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(14px);
    transition: opacity .3s var(--ease), transform .3s var(--ease),
                visibility .3s, background .25s var(--ease), color .25s var(--ease);
}

.to-top.is-on { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--accent); color: var(--paper); border-color: var(--accent); }

.to-top svg { width: 16px; height: 16px; }

/* ---------- 12. 章节导航（吸顶） ---------- */
.subnav {
    position: sticky;
    top: var(--nav-h-sm);
    z-index: 90;
    background: rgba(246, 239, 226, .95);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line);
}

.subnav-inner {
    display: flex;
    align-items: center;
    gap: 4px;
    max-width: 1360px;
    margin: 0 auto;
    padding: 0 40px;
    height: 56px;
    overflow-x: auto;
    scrollbar-width: none;
}

.subnav-inner::-webkit-scrollbar { display: none; }

.subnav-label {
    flex: 0 0 auto;
    margin-right: 18px;
    font-family: var(--font-deco);
    font-size: 13px;
    letter-spacing: 4px;
    color: var(--ink-3);
}

.subnav a {
    position: relative;
    flex: 0 0 auto;
    padding: 6px 16px;
    font-size: 13.5px;
    letter-spacing: 2px;
    color: var(--ink-2);
    white-space: nowrap;
    transition: color .22s var(--ease), background .22s var(--ease);
}

.subnav a::after {
    content: "";
    position: absolute;
    left: 16px;
    right: 16px;
    bottom: -1px;
    height: 2px;
    background: var(--accent-2);
    transform: scaleX(0);
    transition: transform .28s var(--ease);
}

.subnav a:hover { color: var(--accent-2); }
.subnav a.is-active { color: var(--accent-2); }
.subnav a.is-active::after { transform: scaleX(1); }

/* ---------- 13. 图片灯箱 ---------- */
.lightbox {
    position: fixed;
    inset: 0;
    z-index: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    background: rgba(38, 30, 22, .82);
    backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    transition: opacity .3s var(--ease), visibility .3s;
}

.lightbox.is-open { opacity: 1; visibility: visible; }

.lightbox figure {
    position: relative;
    max-width: min(1040px, 92vw);
    max-height: 86vh;
    padding: 12px;
    background: var(--card);
    box-shadow: 0 30px 70px rgba(0, 0, 0, .4);
    transform: scale(.94);
    transition: transform .35s var(--ease-out);
}

.lightbox.is-open figure { transform: none; }

.lightbox img {
    max-width: 100%;
    max-height: 74vh;
    object-fit: contain;
}

.lightbox figcaption {
    padding: 12px 4px 4px;
    font-family: var(--font-deco);
    font-size: 14px;
    letter-spacing: 2px;
    color: var(--ink-2);
    text-align: center;
}

.lightbox-close {
    position: absolute;
    top: -46px;
    right: 0;
    width: 36px;
    height: 36px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    color: var(--paper);
    background: transparent;
    border: 1px solid rgba(246, 239, 226, .5);
    border-radius: 50%;
    cursor: pointer;
    transition: background .2s var(--ease), border-color .2s var(--ease);
}

.lightbox-close:hover { background: rgba(246, 239, 226, .16); border-color: var(--paper); }

/* ---------- 14. 响应式 ---------- */
/* 1180 以下：内容区收窄，导航仍保持横排，避免浏览器放大时变成汉堡 */
@media (max-width: 1180px) {
    .container { padding: 0 26px; }
    .nav-wrap { padding: 0 26px; }
    .subnav-inner { padding: 0 26px; }
}

@media (max-width: 1180px) and (min-width: 901px) {
    .nav-item > a { padding: 9px 14px; font-size: 15px; letter-spacing: 2px; }
    .nav-main { gap: 2px; }
}

/* 900 以下：切换为右侧抽屉 */
@media (max-width: 900px) {
    nav[aria-label="主导航"] {
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        left: auto;
        width: min(86vw, 380px);
        max-width: 100%;
        padding: calc(var(--nav-h) + 20px) 26px 40px;
        background: var(--card);
        border-left: 1px solid var(--line);
        box-shadow: -18px 0 50px rgba(46, 36, 27, .18);
        overflow-y: auto;
        overscroll-behavior: contain;
        transform: translateX(102%);
        transition: transform .42s var(--ease);
        z-index: 210;
        display: block;
    }

    .top-nav.is-open nav[aria-label="主导航"] { transform: none; }
    .top-nav.is-open .nav-mask { opacity: 1; visibility: visible; }

    nav[aria-label="主导航"]::before {
        content: "百香集 · 目录";
        display: block;
        margin-bottom: 14px;
        padding-bottom: 14px;
        font-family: var(--font-deco);
        font-size: 12.5px;
        letter-spacing: 4px;
        color: var(--ink-3);
        border-bottom: 1px solid var(--line);
    }

    .nav-toggle { display: flex; }
    .nav-main { flex-direction: column; align-items: stretch; gap: 0; }

    .nav-item > a {
        padding: 14px 6px;
        font-size: 16px;
        letter-spacing: 3px;
        border-bottom: 1px solid var(--line-soft);
    }

    .nav-item > a::before { display: none; }
    .nav-item.has-sub > a::after { margin-left: auto; }

    .nav-sub {
        position: static;
        min-width: 0;
        max-height: 0;
        padding: 0;
        overflow: hidden;
        opacity: 1;
        visibility: visible;
        transform: none;
        background: transparent;
        border: none;
        border-left: 1px solid var(--line);
        box-shadow: none;
        margin-left: 10px;
        transition: max-height .38s var(--ease), padding .38s var(--ease);
    }

    .nav-item.is-open .nav-sub { padding: 4px 0 8px; }

    .nav-sub li a { padding: 9px 16px; font-size: 14px; }
    .nav-sub li a:hover { background: transparent; }
}

@media (max-width: 900px) {
    .banner { min-height: 380px; }
    .banner-inner { padding: 28px 26px; }
    .banner-copy { padding-left: 22px; max-width: 560px; }
    .banner-copy h1 { letter-spacing: 8px; }
    .section { padding: 72px 0; }
    .section-head { margin-bottom: 40px; }
    .section-head h2 { padding: 0 40px; }
    .section-head h2::before,
    .section-head h2::after { width: 26px; }
    .subnav-inner { height: 50px; }
}

@media (max-width: 600px) {
    :root { --nav-h: 60px; --nav-h-sm: 56px; }

    body { font-size: 14px; }
    .container { padding: 0 18px; }
    .nav-wrap { padding: 0 18px; }
    .subnav-inner { padding: 0 18px; }

    .logo img { height: 30px; }
    .top-nav.is-scrolled .logo img { height: 27px; }

    .banner { min-height: 300px; align-items: flex-end; }
    .banner::before {
        background:
            linear-gradient(0deg, rgba(246, 239, 226, .97) 0%, rgba(246, 239, 226, .92) 40%,
            rgba(246, 239, 226, .5) 66%, rgba(246, 239, 226, 0) 100%);
    }
    .banner-inner { padding: 20px 18px 26px; }
    .banner-copy { padding-left: 16px; max-width: 100%; }
    .banner-copy h1 { font-size: 30px; letter-spacing: 6px; text-indent: 2px; }
    .banner-sub { margin-top: 10px; font-size: 13px; letter-spacing: 3px; }
    .breadcrumb { margin-bottom: 16px; font-size: 11px; gap: 6px; }
    .banner-meta { margin-top: 18px; gap: 12px; }
    .banner-seal { width: 32px; height: 32px; font-size: 17px; }

    .section { padding: 56px 0; }
    .section-head { margin-bottom: 32px; }

    /* 章节导航：窄屏隐藏标签、收紧间距，五个栏目也能一屏放下 */
    .subnav-label { display: none; }
    .subnav-inner { gap: 2px; height: 48px; }
    .subnav a { padding: 6px 9px; font-size: 12.5px; letter-spacing: 0; }
    .subnav a::after { left: 9px; right: 9px; }
    .section-head h2 { padding: 0 24px; font-size: 24px; letter-spacing: 5px; }
    .section-head h2::before,
    .section-head h2::after { width: 16px; }
    .section-head p { margin-top: 12px; font-size: 13.5px; letter-spacing: 2px; }

    .lead { font-size: 15px; }

    footer { padding: 40px 0 34px; }
    .foot-inner { padding: 0 18px; }
    .foot-brand { font-size: 14px; letter-spacing: 4px; }

    .to-top { right: 16px; bottom: 18px; width: 42px; height: 42px; }
    .lightbox { padding: 20px; }
    .lightbox-close { top: -42px; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *,
    *::before,
    *::after {
        animation-duration: .001ms !important;
        animation-delay: 0ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: .001ms !important;
    }
    .js .reveal,
    .js .reveal.is-in {
        opacity: 1;
        transform: none;
        animation: none;
    }
}