/* ==========================================================================
   四季官网 · 共享样式表 /assets/site.css
   纸感基底 + 墨线骨架 + 枫红锚点 + 四季识别色
   ========================================================================== */

/* ---------- 1. 变量 ---------- */
:root{
  color-scheme: light;

  --paper-000:#F7F3EA;
  --paper-100:#EBE4D6;
  --paper-200:#E1D9C9;
  --mist-050:#E4E7E6;

  --ink-900:#14120F;
  --ink-600:#4B4740;
  --ink-300:#8B8478;

  --anchor-600:#B23A2E;
  --anchor-500:#C7503F;

  --spring-400:#7FA46A;
  --spring-200:#E3B4B0;
  --summer-500:#3F7F96;
  --summer-600:#5C8B5F;
  --autumn-300:#DDA45E;
  --winter-700:#1F2B45;

  --rule:rgba(20,18,15,.14);
  --rule-2:rgba(20,18,15,.32);
  --glass:rgba(247,243,234,.78);
  --glass-strong:rgba(247,243,234,.94);

  --font-display:"Source Han Serif SC","Noto Serif SC","Songti SC","STSong","FangSong",serif;
  --font-ui:"Noto Sans SC","PingFang SC","HarmonyOS Sans SC","Microsoft YaHei",sans-serif;
  --font-figure:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;

  --shell-max:1200px;
  --gutter:clamp(1rem,4vw,2.5rem);
  --hair:1px;
  --r-xs:2px;
  --r-sm:4px;
  --r-md:10px;
  --pill:999px;

  --shadow-float:0 14px 34px -22px rgba(20,18,15,.55);
  --shadow-paper:0 26px 60px -44px rgba(20,18,15,.65);

  --ease:cubic-bezier(.22,.72,.28,1);
}

/* ---------- 2. 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-padding-top:5.5rem;
}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd,fieldset{margin:0}
ul[class],ol[class]{list-style:none;padding:0}
img,svg,video{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
:focus{outline:none}
:focus-visible{
  outline:2px solid var(--anchor-600);
  outline-offset:3px;
  border-radius:var(--r-xs);
}
.footer-band--colophon :focus-visible{outline-color:var(--autumn-300)}

/* ---------- 3. 纸面与中文排版 ---------- */
body{
  font-family:var(--font-ui);
  font-size:1.0625rem;
  line-height:1.85;
  color:var(--ink-900);
  background-color:var(--paper-000);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:5;
  pointer-events:none;
  opacity:.6;
  background-image:
    repeating-linear-gradient(0deg, rgba(20,18,15,.022) 0 .5px, transparent .5px 2px),
    repeating-linear-gradient(90deg, rgba(20,18,15,.017) 0 .5px, transparent .5px 3px);
}
h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:600;
  line-height:1.2;
  letter-spacing:-.01em;
}
h1{font-size:clamp(2.25rem,5.6vw,4rem);letter-spacing:-.02em}
h2{font-size:clamp(1.75rem,3.6vw,2.625rem)}
h3{font-size:clamp(1.25rem,2.1vw,1.625rem)}
p{max-width:38em}
strong{font-weight:600}
a:not([class]){border-bottom:1px solid var(--rule-2)}
a:not([class]):hover{border-bottom-color:var(--anchor-600);color:var(--anchor-600)}

.visually-hidden{
  position:absolute!important;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  clip-path:inset(50%);
  white-space:nowrap;
  border:0;
}

/* ---------- 4. 布局工具 ---------- */
.shell{
  width:100%;
  max-width:var(--shell-max);
  margin-inline:auto;
}
.section{
  padding-block:clamp(3rem,7vw,6.5rem);
  padding-inline:var(--gutter);
}
.section__head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  justify-content:space-between;
  gap:.75rem 2rem;
  max-width:var(--shell-max);
  margin-inline:auto;
  padding-bottom:1rem;
  margin-bottom:clamp(1.5rem,3vw,2.75rem);
  border-bottom:var(--hair) solid var(--rule-2);
}
.eyebrow{
  font-family:var(--font-figure);
  font-size:.75rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--ink-600);
}
.lede{
  font-size:clamp(1.0625rem,1.5vw,1.25rem);
  line-height:1.9;
  color:var(--ink-600);
  max-width:34em;
}

/* ---------- 5. 按钮 ---------- */
.button{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.4rem;
  padding:.62rem 1.15rem;
  border:var(--hair) solid transparent;
  border-radius:var(--pill);
  font-size:.9375rem;
  font-weight:500;
  letter-spacing:.02em;
  line-height:1.3;
  white-space:nowrap;
  transition:background-color .2s var(--ease),color .2s var(--ease),
             border-color .2s var(--ease),transform .2s var(--ease);
}
.button--primary{
  background:var(--anchor-600);
  border-color:var(--anchor-600);
  color:var(--paper-000);
}
.button--primary:hover{background:var(--anchor-500);border-color:var(--anchor-500)}
.button--ghost{
  background:transparent;
  border-color:var(--rule-2);
  color:var(--ink-900);
}
.button--ghost:hover{background:var(--paper-100);border-color:var(--ink-900)}

/* ---------- 6. 跳转链接 ---------- */
.skip-link{
  position:fixed;
  left:1rem;
  top:-5rem;
  z-index:200;
  padding:.7rem 1.15rem;
  border-radius:var(--pill);
  background:var(--ink-900);
  color:var(--paper-000);
  font-size:.9rem;
  box-shadow:var(--shadow-float);
  transition:top .22s var(--ease);
}
.skip-link:focus{top:1rem;outline-color:var(--autumn-300)}

/* ---------- 7. 头部 · 悬浮胶囊导航 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:80;
  padding:.7rem var(--gutter);
  background:linear-gradient(to bottom,var(--paper-000) 42%,rgba(247,243,234,.55) 78%,rgba(247,243,234,0));
  transition:padding .3s var(--ease);
}
.site-header[data-condensed]{padding-top:.3rem;padding-bottom:.3rem}

.header-shell{
  display:flex;
  align-items:center;
  gap:.55rem;
  max-width:var(--shell-max);
  margin-inline:auto;
  padding:.5rem .55rem .5rem .95rem;
  border:var(--hair) solid var(--rule);
  border-radius:var(--pill);
  background:var(--glass);
  -webkit-backdrop-filter:blur(14px) saturate(1.25);
  backdrop-filter:blur(14px) saturate(1.25);
  box-shadow:var(--shadow-float);
  transition:padding .3s var(--ease),background-color .3s var(--ease),
             border-radius .3s var(--ease),box-shadow .3s var(--ease);
}
.site-header[data-condensed] .header-shell{
  padding-block:.28rem;
  background:var(--glass-strong);
  box-shadow:0 8px 26px -20px rgba(20,18,15,.7);
}

/* 品牌胶囊 */
.brand-pill{
  display:inline-flex;
  align-items:baseline;
  gap:.5rem;
  flex:0 0 auto;
  padding:.3rem .2rem;
  white-space:nowrap;
}
.brand-pill__mark{
  font-family:var(--font-display);
  font-size:1.3rem;
  font-weight:600;
  letter-spacing:.2em;
}
.brand-pill__claim{
  font-family:var(--font-figure);
  font-size:.6875rem;
  letter-spacing:.2em;
  color:var(--ink-600);
}
.brand-pill:hover .brand-pill__mark{color:var(--anchor-600)}

/* 抽屉开关 */
.nav-toggle{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  margin-left:auto;
  padding:.5rem .8rem;
  border:var(--hair) solid var(--rule-2);
  border-radius:var(--pill);
  font-size:.875rem;
  letter-spacing:.08em;
  color:var(--ink-900);
  transition:background-color .2s var(--ease),border-color .2s var(--ease);
}
.nav-toggle:hover{background:rgba(20,18,15,.05);border-color:var(--ink-900)}
.nav-toggle__bars{
  display:inline-flex;
  flex-direction:column;
  justify-content:center;
  gap:3px;
  width:14px;
  height:12px;
}
.nav-toggle__bar{
  display:block;
  height:1.5px;
  border-radius:2px;
  background:currentColor;
  transition:transform .25s var(--ease),opacity .2s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(4.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3){transform:translateY(-4.5px) rotate(-45deg)}
.nav-toggle__label{line-height:1}

/* 主导航 */
.site-nav{display:none;min-width:0}
.site-nav__list{
  display:flex;
  align-items:center;
  justify-content:center;
  gap:.1rem;
}
.site-nav__link{
  position:relative;
  display:inline-block;
  padding:.5rem .78rem;
  border-radius:var(--pill);
  font-size:.9375rem;
  color:var(--ink-600);
  transition:color .2s var(--ease),background-color .2s var(--ease);
}
.site-nav__link:hover{color:var(--ink-900);background:rgba(20,18,15,.05)}
.site-nav__link[aria-current="page"]{color:var(--ink-900);font-weight:600}
.site-nav__link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:.78rem;
  right:.78rem;
  bottom:.26rem;
  height:2px;
  border-radius:2px;
  background:var(--anchor-600);
}

/* 工具区 */
.header-tools{display:none;flex:0 0 auto;align-items:center;gap:.5rem;min-width:0}
.header-cta{font-size:.875rem;padding:.55rem 1rem}

.nav-search{position:relative;min-width:0}
.nav-search__input{
  width:10.5rem;
  padding:.5rem .95rem;
  border:var(--hair) solid var(--rule);
  border-radius:var(--pill);
  background:rgba(255,255,255,.55);
  font-size:.875rem;
  color:var(--ink-900);
  transition:width .3s var(--ease),border-color .2s var(--ease),background-color .2s var(--ease);
}
.nav-search__input::placeholder{color:var(--ink-300)}
.nav-search__input:focus{
  width:13rem;
  border-color:var(--rule-2);
  background:#fff;
}
.nav-search__input:focus-visible{outline-offset:2px}

.search-results{
  position:absolute;
  top:calc(100% + .55rem);
  right:0;
  z-index:20;
  width:min(20rem,78vw);
  max-height:min(60vh,22rem);
  overflow:auto;
  margin:0;
  padding:.35rem;
  list-style:none;
  background:var(--paper-000);
  border:var(--hair) solid var(--rule-2);
  border-radius:var(--r-md);
  box-shadow:var(--shadow-paper);
}
.search-results[hidden]{display:none}
.search-results__link{
  display:block;
  padding:.5rem .65rem;
  border-radius:var(--r-sm);
  font-size:.9rem;
  color:var(--ink-900);
  transition:background-color .18s var(--ease);
}
.search-results__link:hover,
.search-results__link:focus-visible{background:var(--paper-100)}
.search-results__meta{
  display:block;
  margin-top:.12rem;
  font-family:var(--font-figure);
  font-size:.6875rem;
  letter-spacing:.04em;
  color:var(--ink-600);
}
.search-results__hint{
  padding:.55rem .65rem;
  font-size:.85rem;
  color:var(--ink-600);
}

/* ---------- 8. 页脚 ---------- */
.site-footer{
  margin-top:clamp(3rem,7vw,6rem);
  border-top:var(--hair) solid var(--rule-2);
  background:var(--paper-000);
  color:var(--ink-900);
}
.footer-band{padding-block:clamp(2rem,5vw,3.5rem);padding-inline:var(--gutter)}
.footer-band--index{background:var(--paper-000)}
.footer-band--season{background:var(--paper-100)}
.footer-band--colophon{
  background:var(--ink-900);
  color:var(--paper-000);
  padding-block:clamp(1.5rem,3vw,2.25rem);
}
.footer-shell{width:100%;max-width:var(--shell-max);margin-inline:auto}

.footer-band--index .footer-shell{
  display:grid;
  grid-template-columns:minmax(0,1.35fr) repeat(2,minmax(0,1fr));
  gap:clamp(1.5rem,4vw,3.5rem);
}
.footer-intro{max-width:26rem}
.footer-brand__name{
  font-family:var(--font-display);
  font-size:1.375rem;
  letter-spacing:.14em;
  line-height:1.4;
}
.footer-brand__claim{
  margin-top:.5rem;
  font-size:.875rem;
  line-height:1.85;
  color:var(--ink-600);
}
.footer-col__title{
  font-family:var(--font-figure);
  font-size:.75rem;
  letter-spacing:.2em;
  color:var(--ink-600);
  padding-bottom:.65rem;
  margin-bottom:.75rem;
  border-bottom:var(--hair) solid var(--rule);
}
.footer-nav__list{display:flex;flex-direction:column;gap:.35rem}
.footer-nav__link{
  display:inline-block;
  font-size:.9375rem;
  line-height:1.9;
  color:var(--ink-900);
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-nav__link:hover{
  color:var(--anchor-600);
  border-bottom-color:var(--anchor-600);
}

.season-strip{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:clamp(1rem,3vw,2rem);
}
.season-strip__item{
  display:block;
  padding-top:.7rem;
  border-top:2px solid currentColor;
  color:var(--ink-600);
}
.season-strip__item--spring{color:var(--spring-400)}
.season-strip__item--summer{color:var(--summer-500)}
.season-strip__item--autumn{color:var(--autumn-300)}
.season-strip__item--winter{color:var(--winter-700)}
.season-strip__label{
  display:block;
  font-family:var(--font-display);
  font-size:1.0625rem;
  letter-spacing:.1em;
  color:var(--ink-900);
}
.season-strip__note{
  display:block;
  margin-top:.15rem;
  font-size:.8125rem;
  line-height:1.7;
  color:var(--ink-600);
}

.footer-colophon{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:.5rem 1.75rem;
}
.footer-notice{
  font-family:var(--font-figure);
  font-size:.8125rem;
  letter-spacing:.04em;
  color:var(--autumn-300);
}
.footer-contact{font-size:.875rem;color:rgba(247,243,234,.82);max-width:none}
.footer-legal{
  font-family:var(--font-figure);
  font-size:.8125rem;
  color:rgba(247,243,234,.62);
  max-width:none;
}
.footer-copy{
  font-family:var(--font-figure);
  font-size:.8125rem;
  color:rgba(247,243,234,.62);
  margin-left:auto;
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb{
  padding:1.15rem var(--gutter) 0;
  font-size:.8125rem;
  color:var(--ink-600);
}
.breadcrumb__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.35rem;
  max-width:var(--shell-max);
  margin-inline:auto;
}
.breadcrumb__item{display:inline-flex;align-items:center;gap:.35rem}
.breadcrumb__item::after{content:"／";color:var(--ink-300)}
.breadcrumb__item:last-child::after{display:none}
.breadcrumb__link{color:var(--ink-600);transition:color .2s var(--ease)}
.breadcrumb__link:hover{color:var(--anchor-600)}

/* ---------- 10. 图片容器基础规则 ---------- */
.media{
  position:relative;
  overflow:hidden;
  width:100%;
  background:var(--paper-100);
  border:var(--hair) solid var(--rule);
  border-radius:var(--r-md);
}
.media__img{
  width:100%;
  height:100%;
  object-fit:cover;
  filter:saturate(.94) contrast(1.02);
}
.media__tag{
  position:absolute;
  left:0;
  bottom:0;
  padding:.32rem .8rem;
  font-family:var(--font-figure);
  font-size:.6875rem;
  letter-spacing:.12em;
  background:var(--paper-000);
  color:var(--ink-600);
  border-top:var(--hair) solid var(--rule);
  border-right:var(--hair) solid var(--rule);
  border-top-right-radius:var(--r-sm);
}
.media__caption{
  margin-top:.55rem;
  font-family:var(--font-figure);
  font-size:.75rem;
  letter-spacing:.03em;
  line-height:1.7;
  color:var(--ink-600);
}
.media--portrait{aspect-ratio:3 / 4}
.media--landscape{aspect-ratio:16 / 10}
.media--square{aspect-ratio:1 / 1}
.media--wide{aspect-ratio:21 / 9}

/* ---------- 11. 滚动显现协议 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .32s ease-out,transform .32s ease-out;
  will-change:opacity,transform;
}
[data-reveal].is-visible{opacity:1;transform:none}
[data-reveal-order="1"]{transition-delay:.06s}
[data-reveal-order="2"]{transition-delay:.12s}
[data-reveal-order="3"]{transition-delay:.18s}
[data-reveal-order="4"]{transition-delay:.24s}

/* ---------- 12. 响应式 ---------- */
@media (max-width:1099px){
  .header-shell{flex-wrap:wrap;border-radius:20px;padding:.55rem .75rem;gap:.5rem}
  .brand-pill{flex:1 1 auto}
  .site-header[data-open] .site-nav{
    display:block;
    order:3;
    flex:1 1 100%;
    padding-top:.55rem;
    margin-top:.15rem;
    border-top:var(--hair) solid var(--rule);
  }
  .site-header[data-open] .site-nav__list{
    flex-direction:column;
    align-items:stretch;
    gap:.1rem;
  }
  .site-header[data-open] .site-nav__link{
    display:block;
    padding:.7rem .6rem;
    border-radius:var(--r-sm);
    font-size:1rem;
  }
  .site-header[data-open] .site-nav__link:hover{background:var(--paper-100)}
  .site-header[data-open] .site-nav__link[aria-current="page"]{background:var(--paper-100)}
  .site-header[data-open] .site-nav__link[aria-current="page"]::after{
    left:.6rem;
    right:auto;
    width:2.4rem;
    bottom:.42rem;
  }
  .site-header[data-open] .header-tools{
    display:flex;
    order:4;
    flex:1 1 100%;
    flex-direction:column;
    align-items:stretch;
    gap:.6rem;
    padding-top:.8rem;
    border-top:var(--hair) solid var(--rule);
  }
  .site-header[data-open] .nav-search,
  .site-header[data-open] .nav-search__input,
  .site-header[data-open] .header-cta{width:100%}
  .site-header[data-open] .nav-search__input:focus{width:100%}
  .search-results{left:0;right:auto;width:100%}
}

@media (min-width:1100px){
  .site-nav{display:block;flex:1 1 auto}
  .header-tools{display:flex}
  .nav-toggle{display:none}
}

@media (max-width:900px){
  .footer-band--index .footer-shell{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-intro{grid-column:1 / -1;max-width:34rem}
  .season-strip{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-copy{margin-left:0}
}

@media (max-width:600px){
  body{font-size:1rem;line-height:1.8}
  .brand-pill__claim{display:none}
  .section{padding-block:clamp(2.25rem,9vw,3.5rem)}
  .footer-band--index .footer-shell{grid-template-columns:1fr}
  .season-strip{grid-template-columns:1fr}
  .footer-colophon{flex-direction:column;gap:.4rem}
}

@media (max-width:420px){
  .nav-toggle__label{display:none}
}

/* ---------- 13. 动效降级 ---------- */
@media (prefers-reduced-motion: no-preference){
  html{scroll-behavior:smooth}
}

@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
    transition-duration:.001ms!important;
    transition-delay:0s!important;
    scroll-behavior:auto!important;
  }
  [data-reveal]{opacity:1!important;transform:none!important}
  body::before{opacity:.4}
}