/* =========================================================
   四季品牌站 · /assets/site.css
   reset / 变量 / 中文排版 / 侧边轨道头部 / 页脚 / 通用组件
   ========================================================= */

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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--bar-h) + 22px);
}

body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
img,svg,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}

:root{
  /* 四季骨架色 */
  --spring:#7BAE7F;
  --summer:#E4573D;
  --autumn:#D9A441;
  --winter:#3E5F8A;
  /* 辅助色 */
  --spring-soft:#B8CDB9;
  --winter-soft:#A9BBD1;
  --sand:#EFE3CE;
  --gold-deep:#9C7728;
  /* 基底 */
  --paper:#F6F1E7;
  --paper-hi:#FBF8F1;
  --ink:#1F1B16;
  --ink-70:rgba(31,27,22,.72);
  --ink-50:rgba(31,27,22,.52);
  --line:rgba(31,27,22,.14);
  --line-strong:rgba(31,27,22,.3);
  /* 随季节流动的强调色 */
  --flow:var(--winter);
  /* 尺寸与节奏 */
  --rail-w:288px;
  --rail-offset:0px;
  --bar-h:58px;
  --maxw:1180px;
  --pad-x:clamp(18px,4vw,44px);
  --r-s:8px;
  --r-m:14px;
  --r-l:22px;
  --shadow-s:0 1px 2px rgba(31,27,22,.06);
  --shadow-m:0 18px 44px -30px rgba(31,27,22,.55);
  /* 字体 */
  --serif:"Source Han Serif SC","Noto Serif SC","Songti SC",STSong,"SimSun",serif;
  --sans:"Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;
}

:root[data-active-season="spring"]{--flow:var(--spring)}
:root[data-active-season="summer"]{--flow:var(--summer)}
:root[data-active-season="autumn"]{--flow:var(--autumn)}
:root[data-active-season="winter"]{--flow:var(--winter)}

/* ---------- 页面基底 ---------- */
body{
  font-family:var(--sans);
  font-size:16px;
  line-height:1.8;
  color:var(--ink);
  background-color:var(--paper);
  background-image:
    radial-gradient(1100px 520px at 94% -6%, rgba(169,187,209,.30), transparent 62%),
    radial-gradient(820px 460px at -8% 10%, rgba(184,205,185,.26), transparent 64%);
  background-repeat:no-repeat;
  -webkit-font-smoothing:antialiased;
  padding-left:0;
  min-height:100vh;
}

#main-content{display:block}
#main-content:focus{outline:none}

/* ---------- 中文排版层级 ---------- */
h1,h2,h3,h4{font-family:var(--serif);font-weight:700;line-height:1.28;letter-spacing:.01em}
h1{font-size:clamp(28px,4.4vw,56px)}
h2{font-size:clamp(22px,2.6vw,34px)}
h3{font-size:clamp(18px,1.8vw,24px)}
h4{font-size:17px}
p{color:var(--ink-70)}
strong{font-weight:600;color:var(--ink)}

:focus-visible{outline:2px solid var(--winter);outline-offset:3px;border-radius:4px}
.site-rail :focus-visible,.mobile-bar :focus-visible{outline-color:var(--summer)}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* ---------- 布局容器 ---------- */
.wrap{
  width:100%;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--pad-x);
}
.section{padding-block:clamp(40px,6vw,84px)}
.section__head{display:grid;gap:10px;margin-bottom:clamp(20px,3vw,34px)}
.eyebrow{
  font-family:var(--mono);
  font-size:11.5px;
  font-weight:500;
  letter-spacing:.24em;
  text-transform:uppercase;
  color:var(--gold-deep);
}
.lede{font-size:clamp(16px,1.35vw,19px);line-height:1.8;color:var(--ink-70);max-width:62ch}

/* ---------- 跳至主内容 ---------- */
.skip-link{
  position:fixed;
  left:calc(var(--rail-offset) + 14px);
  top:-72px;
  z-index:200;
  display:inline-block;
  padding:10px 18px;
  background:var(--ink);
  color:var(--paper);
  font-size:14px;
  border-radius:0 0 var(--r-s) var(--r-s);
  transition:top .18s ease;
}
.skip-link:focus{top:0}

/* ---------- 四季标记方块 ---------- */
.season-mark{
  display:block;
  flex:0 0 auto;
  width:26px;
  height:26px;
  border-radius:7px;
  background:conic-gradient(var(--spring) 0 25%, var(--summer) 0 50%, var(--autumn) 0 75%, var(--winter) 0);
  box-shadow:inset 0 0 0 1px rgba(31,27,22,.1);
}
.season-mark--sm{width:18px;height:18px;border-radius:5px}
.season-mark--lg{width:36px;height:36px;border-radius:10px}

/* ---------- 侧边轨道头部 ---------- */
.site-rail{
  position:fixed;
  top:0;left:0;bottom:0;
  z-index:80;
  width:min(88vw,330px);
  display:flex;
  flex-direction:column;
  background:linear-gradient(180deg,#FBF8F1 0%,#F1E7D6 62%,#F6F1E7 100%);
  border-right:1px solid var(--line);
  overflow-y:auto;
  overscroll-behavior:contain;
  transform:translateX(-103%);
  transition:transform .28s cubic-bezier(.4,0,.2,1),box-shadow .28s ease;
}
.site-rail[data-open="true"]{
  transform:translateX(0);
  box-shadow:26px 0 70px -46px rgba(31,27,22,.6);
}

.rail-ribbon{
  position:absolute;left:0;top:0;bottom:0;width:6px;
  background:linear-gradient(180deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%);
  opacity:.26;
  pointer-events:none;
}
.rail-flow{
  position:absolute;left:0;top:0;width:6px;height:25%;
  background:var(--flow);
  transform:translateY(0);
  transition:transform .45s cubic-bezier(.4,0,.2,1),background-color .45s ease;
  pointer-events:none;
}
.site-rail[data-flow-index="1"] .rail-flow{transform:translateY(100%)}
.site-rail[data-flow-index="2"] .rail-flow{transform:translateY(200%)}
.site-rail[data-flow-index="3"] .rail-flow{transform:translateY(300%)}

.rail-inner{
  position:relative;
  flex:1 1 auto;
  display:flex;
  flex-direction:column;
  gap:24px;
  padding:calc(var(--bar-h) + 24px) 20px 26px 26px;
}

.rail-brand{display:flex;flex-direction:column;gap:8px}
.rail-brand__name{
  font-family:var(--serif);
  font-weight:700;
  font-size:24px;
  line-height:1.2;
  letter-spacing:.02em;
}
.rail-brand__line{
  font-family:var(--mono);
  font-size:11.5px;
  line-height:1.6;
  letter-spacing:.03em;
  color:var(--ink-50);
}

.rail-quick{
  display:grid;
  gap:10px;
  padding:13px 12px 15px;
  border:1px solid var(--line);
  border-radius:var(--r-m);
  background:rgba(255,255,255,.58);
  box-shadow:var(--shadow-s);
}
.rail-quick__label{
  font-family:var(--mono);
  font-size:10.5px;
  font-weight:500;
  letter-spacing:.24em;
  color:var(--gold-deep);
}
.rail-quick__list{display:grid;gap:3px}
.rail-quick__link{
  display:grid;
  grid-template-columns:auto 1fr;
  gap:9px;
  align-items:baseline;
  padding:7px 9px;
  border-radius:var(--r-s);
  font-size:13.5px;
  line-height:1.5;
  color:var(--ink);
  transition:background-color .16s ease,transform .16s ease;
}
.rail-quick__link:hover{background:rgba(217,164,65,.2);transform:translateX(2px)}
.rail-quick__idx{
  font-family:var(--mono);
  font-size:10.5px;
  color:var(--gold-deep);
}

.rail-nav{margin-top:-4px}
.rail-nav__list{display:grid;gap:2px}
.rail-link{
  position:relative;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  padding:9px 12px;
  border-radius:10px;
  font-size:15px;
  color:var(--ink-70);
  transition:background-color .16s ease,color .16s ease,box-shadow .2s ease;
}
.rail-link::after{
  content:"";
  width:6px;height:6px;border-radius:50%;
  background:var(--line-strong);
  transition:background-color .2s ease,transform .2s ease;
}
.rail-link:hover{background:rgba(62,95,138,.1);color:var(--ink)}
.rail-link[aria-current="page"]{
  background:rgba(62,95,138,.13);
  color:var(--ink);
  font-weight:600;
  box-shadow:inset 3px 0 0 var(--flow);
}
.rail-link[aria-current="page"]::after{background:var(--flow);transform:scale(1.35)}

.rail-foot{
  margin-top:auto;
  display:grid;
  gap:10px;
  padding-top:18px;
  border-top:1px dashed var(--line);
}
.rail-foot__label{
  font-family:var(--mono);
  font-size:10.5px;
  letter-spacing:.24em;
  color:var(--ink-50);
}
.rail-legend{display:grid;grid-template-columns:1fr 1fr;gap:7px 12px}
.rail-legend__item{
  display:flex;
  align-items:center;
  gap:7px;
  font-family:var(--mono);
  font-size:12px;
  color:var(--ink-70);
}
.rail-legend__dot{width:8px;height:8px;border-radius:2px;background:var(--winter)}
.rail-legend__item--spring .rail-legend__dot{background:var(--spring)}
.rail-legend__item--summer .rail-legend__dot{background:var(--summer)}
.rail-legend__item--autumn .rail-legend__dot{background:var(--autumn)}
.rail-legend__item--winter .rail-legend__dot{background:var(--winter)}
.rail-foot__note{font-size:11.5px;line-height:1.7;color:var(--ink-50)}

/* ---------- 移动端品牌条与开关 ---------- */
.mobile-bar{
  position:sticky;
  top:0;
  z-index:90;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  min-height:var(--bar-h);
  padding:8px var(--pad-x);
  background:rgba(246,241,231,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(8px);
}
.mobile-bar__brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--serif);
  font-weight:700;
  font-size:18px;
  letter-spacing:.02em;
}
.nav-toggle{
  position:relative;
  z-index:96;
  display:inline-flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:5px;
  width:44px;
  height:44px;
  border:1px solid var(--line-strong);
  border-radius:12px;
  background:rgba(255,255,255,.72);
  transition:background-color .16s ease,border-color .16s ease;
}
.nav-toggle:hover{border-color:var(--flow);background:#fff}
.nav-toggle__bar{
  width:18px;height:2px;border-radius:2px;
  background:var(--ink);
  transition:transform .22s ease,opacity .18s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(3.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2){transform:translateY(-3.5px) rotate(-45deg)}

.rail-scrim{
  position:fixed;
  left:0;right:0;bottom:0;
  top:var(--bar-h);
  z-index:85;
  background:rgba(31,27,22,.44);
  opacity:0;
  visibility:hidden;
  transition:opacity .24s ease,visibility .24s ease;
}
.rail-scrim[data-open="true"]{opacity:1;visibility:visible}

/* ---------- 顶部阅读进度 ---------- */
.read-progress{
  position:fixed;
  top:0;
  left:var(--rail-offset);
  right:0;
  height:3px;
  z-index:95;
  background:rgba(31,27,22,.07);
  pointer-events:none;
}
.read-progress__bar{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--spring) 0 25%,var(--summer) 25% 50%,var(--autumn) 50% 75%,var(--winter) 75% 100%);
  transition:width .12s linear;
}

/* ---------- 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(48px,8vw,96px);
  background:linear-gradient(180deg,var(--paper-hi) 0%,var(--sand) 100%);
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";
  position:absolute;
  left:0;right:0;top:0;height:4px;
  background:linear-gradient(90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%);
}
.footer-grid{
  display:grid;
  grid-template-columns:1fr;
  gap:clamp(26px,4vw,48px);
  padding-block:clamp(36px,5vw,62px);
}
.footer-brand{display:flex;flex-direction:column;gap:8px}
.footer-brand__name{font-family:var(--serif);font-weight:700;font-size:24px;color:var(--ink)}
.footer-brand__line{font-family:var(--mono);font-size:12px;color:var(--ink-50);letter-spacing:.03em}
.footer-brand__note{margin-top:6px;font-size:14px;line-height:1.8;color:var(--ink-70);max-width:34ch}
.footer-seasons{display:flex;gap:6px;margin-top:14px}
.footer-seasons__band{width:34px;height:6px;border-radius:3px;background:var(--winter)}
.footer-seasons__band--spring{background:var(--spring)}
.footer-seasons__band--summer{background:var(--summer)}
.footer-seasons__band--autumn{background:var(--autumn)}
.footer-seasons__band--winter{background:var(--winter)}

.footer-col{display:block}
.footer-col__title{
  font-family:var(--mono);
  font-size:11.5px;
  font-weight:500;
  letter-spacing:.24em;
  color:var(--ink-50);
  margin-bottom:14px;
}
.footer-links{display:grid;gap:4px}
.footer-link{
  position:relative;
  display:inline-block;
  padding:5px 0;
  font-size:14.5px;
  color:var(--ink-70);
  transition:color .16s ease;
}
.footer-link::after{
  content:"";
  position:absolute;
  left:0;right:100%;bottom:2px;height:1px;
  background:var(--flow);
  transition:right .22s ease;
}
.footer-link:hover{color:var(--ink)}
.footer-link:hover::after{right:0}

.footer-contact{display:grid;gap:12px}
.footer-contact__row{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.footer-contact__key{
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--ink-50);
  border:1px solid var(--line);
  border-radius:6px;
  padding:1px 7px;
}
.footer-contact__val{font-size:14px;color:var(--ink);word-break:break-all;line-height:1.7}
.footer-contact__row--plain{align-items:flex-start}
.copy-btn{
  border:1px solid var(--line-strong);
  border-radius:999px;
  padding:3px 12px;
  font-size:12px;
  color:var(--ink-70);
  background:rgba(255,255,255,.7);
  transition:background-color .16s ease,border-color .16s ease,color .16s ease;
}
.copy-btn:hover{border-color:var(--flow);color:var(--ink)}
.copy-btn.is-done{background:var(--spring);border-color:var(--spring);color:#fff}
.footer-note{margin-top:14px;font-size:12.5px;line-height:1.8;color:var(--ink-50);max-width:38ch}
.copy-status{
  margin-top:6px;
  min-height:1.4em;
  font-family:var(--mono);
  font-size:11.5px;
  color:var(--gold-deep);
}

.footer-meta{
  display:flex;
  flex-wrap:wrap;
  gap:6px 22px;
  justify-content:space-between;
  align-items:center;
  padding-block:18px;
  border-top:1px dashed var(--line);
  font-family:var(--mono);
  font-size:12.5px;
  color:var(--ink-50);
}
.footer-meta__icp,.footer-meta__copy{margin:0}

/* ---------- 通用按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:11px 20px;
  border:1px solid transparent;
  border-radius:999px;
  font-size:15px;
  font-weight:500;
  line-height:1.4;
  transition:transform .16s ease,background-color .16s ease,border-color .16s ease,color .16s ease;
}
.btn--primary{
  background:linear-gradient(135deg,var(--summer),var(--autumn));
  color:#fff;
  box-shadow:var(--shadow-m);
}
.btn--primary:hover{transform:translateY(-1px)}
.btn--ghost{
  border-color:var(--line-strong);
  background:rgba(255,255,255,.66);
  color:var(--ink);
}
.btn--ghost:hover{border-color:var(--flow);transform:translateY(-1px)}
.btn--quiet{
  padding-inline:4px;
  color:var(--winter);
  border-radius:4px;
}
.btn--quiet::after{content:"→";font-family:var(--mono);font-size:13px}
.btn--quiet:hover{color:var(--summer)}

/* ---------- 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:6px;
  margin-bottom:18px;
  font-family:var(--mono);
  font-size:12.5px;
  color:var(--ink-50);
}
.breadcrumb__sep{opacity:.5}
.breadcrumb a{color:var(--ink-70)}
.breadcrumb a:hover{color:var(--ink);text-decoration:underline}

/* ---------- 网格 / Bento ---------- */
.grid{display:grid;gap:clamp(14px,2vw,24px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(232px,1fr))}

.bento{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:clamp(14px,2vw,22px)}
.bento>*{grid-column:span 6}

/* ---------- 卡片与面板 ---------- */
.card{
  position:relative;
  overflow:hidden;
  padding:clamp(18px,2.4vw,28px);
  border:1px solid var(--line);
  border-radius:var(--r-l);
  background:rgba(255,255,255,.74);
  box-shadow:var(--shadow-s);
}
.card--sand{background:var(--sand);border-color:rgba(31,27,22,.1)}
.card--ink{background:var(--ink);border-color:transparent;color:var(--paper)}
.card--ink p,.card--ink .card__title{color:var(--paper)}
.card__title{font-family:var(--serif);font-weight:700;font-size:19px;color:var(--ink);margin-bottom:8px}

/* ---------- 标签 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 11px;
  border:1px solid var(--line);
  border-radius:999px;
  background:rgba(255,255,255,.72);
  font-family:var(--mono);
  font-size:11.5px;
  letter-spacing:.05em;
  color:var(--ink-70);
  white-space:nowrap;
}
.tag--spring{background:rgba(123,174,127,.16);border-color:var(--spring-soft);color:#3F6444}
.tag--summer{background:rgba(228,87,61,.14);border-color:rgba(228,87,61,.42);color:#9E3018}
.tag--autumn{background:rgba(217,164,65,.18);border-color:rgba(156,119,40,.4);color:#6F5415}
.tag--winter{background:rgba(62,95,138,.14);border-color:var(--winter-soft);color:#2C4666}

/* ---------- 对照表 ---------- */
.table-wrap{
  overflow-x:auto;
  -webkit-overflow-scrolling:touch;
  border:1px solid var(--line);
  border-radius:var(--r-m);
  background:rgba(255,255,255,.68);
}
.data-table{min-width:560px;font-size:14.5px}
.data-table th{
  padding:12px 14px;
  background:rgba(62,95,138,.1);
  border-bottom:1px solid var(--line);
  font-family:var(--mono);
  font-size:12px;
  font-weight:500;
  letter-spacing:.06em;
  text-align:left;
  color:var(--ink);
  white-space:nowrap;
}
.data-table td{
  padding:12px 14px;
  border-bottom:1px solid var(--line);
  vertical-align:top;
  color:var(--ink-70);
}
.data-table tbody tr:last-child td{border-bottom:0}
.data-table td:first-child{color:var(--ink);font-weight:500}

/* ---------- 图片 / 图形容器 ---------- */
.media{
  position:relative;
  overflow:hidden;
  width:100%;
  border:1px solid var(--line);
  border-radius:var(--r-m);
  background:linear-gradient(150deg,var(--paper-hi),var(--sand));
}
.media--4x3{aspect-ratio:4/3}
.media--16x9{aspect-ratio:16/9}
.media--1x1{aspect-ratio:1/1}
.media--wide{aspect-ratio:21/9}
.media>img{width:100%;height:100%;object-fit:cover}
.media__caption{
  margin-top:8px;
  font-family:var(--mono);
  font-size:11.5px;
  line-height:1.6;
  color:var(--ink-50);
}
.figure{display:block;margin:0}

.tex{position:absolute;inset:0;pointer-events:none;opacity:.55}
.tex--leaf{
  background:
    repeating-linear-gradient(115deg,rgba(123,174,127,.26) 0 1px,transparent 1px 9px),
    repeating-linear-gradient(65deg,rgba(123,174,127,.16) 0 1px,transparent 1px 15px);
}
.tex--wheat{background:repeating-linear-gradient(78deg,rgba(217,164,65,.28) 0 1px,transparent 1px 11px)}
.tex--frost{
  background:
    repeating-linear-gradient(0deg,rgba(62,95,138,.18) 0 1px,transparent 1px 13px),
    repeating-linear-gradient(90deg,rgba(62,95,138,.13) 0 1px,transparent 1px 19px);
}
.tex--rain{background:repeating-linear-gradient(102deg,rgba(62,95,138,.22) 0 1px,transparent 1px 8px)}

/* ---------- 滚动显现 ---------- */
html.has-js [data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .5s ease,transform .55s cubic-bezier(.2,.7,.3,1);
}
html.has-js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 移动端滚动锁 ---------- */
@media (max-width:63.98rem){
  html.has-drawer,html.has-drawer body{overflow:hidden}
}

/* ---------- 平板及以上 ---------- */
@media (min-width:48rem){
  .bento__third{grid-column:span 2}
  .bento__half{grid-column:span 3}
  .bento__wide{grid-column:span 4}
  .bento__full{grid-column:span 6}
  .footer-grid{grid-template-columns:1.5fr 1fr 1.35fr}
  .footer-links{grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 18px}
}

/* ---------- 桌面端：轨道常驻 ---------- */
@media (min-width:64rem){
  :root{--rail-offset:288px;--bar-h:0px}
  body{padding-left:var(--rail-offset)}
  .site-rail{
    width:var(--rail-w);
    transform:none;
    box-shadow:none;
  }
  .site-rail[data-open="true"]{transform:none;box-shadow:none}
  .mobile-bar{display:none}
  .rail-scrim{display:none}
  .rail-inner{padding-top:30px}
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.has-js [data-reveal]{opacity:1;transform:none}
  .read-progress__bar{transition:none}
}