:root{
  --mm-rock:#1B2223;
  --mm-rock-2:#2C3637;
  --mm-tundra:#6F8B62;
  --mm-tundra-deep:#425A45;
  --mm-lava:#F26A2E;
  --mm-ice:#8FC7D9;
  --mm-fog:#F2F0EA;
  --mm-stone:#D6D0C4;
  --mm-char:#101515;
  --mm-aurora:#B9E3D4;

  --mm-font-display:"Archivo Black","Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --mm-font-serif:"Noto Serif SC","Source Han Serif SC","Songti SC",Georgia,"Times New Roman",serif;
  --mm-font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --mm-font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --mm-shell:1240px;
  --mm-gutter:clamp(18px,4vw,40px);
  --mm-radius:18px;
  --mm-radius-sm:10px;
  --mm-line:rgba(214,208,196,.16);
  --mm-line-strong:rgba(214,208,196,.32);
  --mm-ease:cubic-bezier(.22,.61,.36,1);
}

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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:132px;
}

body{
  margin:0;
  background:var(--mm-rock);
  color:var(--mm-fog);
  font-family:var(--mm-font-body);
  font-size:clamp(15.5px,.28vw + 14.6px,17px);
  font-weight:400;
  line-height:1.75;
  letter-spacing:0;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

img,svg,picture,video{display:block;max-width:100%;}
ul,ol{margin:0;padding:0;list-style:none;}
button{font:inherit;color:inherit;}
a{color:inherit;text-decoration:none;}
p{margin:0;}
p + p{margin-top:.9em;}

h1,h2,h3,h4,h5,h6{
  margin:0;
  font-family:var(--mm-font-display);
  font-weight:900;
  line-height:1.14;
  letter-spacing:.04em;
}
h1{font-size:clamp(2.4rem,5.6vw,4.6rem);}
h2{font-size:clamp(1.7rem,3.2vw,2.8rem);}
h3{font-size:clamp(1.14rem,1.6vw,1.45rem);}

:focus-visible{
  outline:2px solid var(--mm-ice);
  outline-offset:3px;
  border-radius:4px;
}

#main-content{display:block;}
[data-chapter]{scroll-margin-top:132px;}

/* ---------- 容器与骨架 ---------- */
.mm-shell{
  width:100%;
  max-width:var(--mm-shell);
  margin-inline:auto;
  padding-inline:var(--mm-gutter);
}

.mm-section{padding-block:clamp(48px,7vw,96px);}
.mm-section--light{background:var(--mm-fog);color:var(--mm-char);}
.mm-section--rock{background:var(--mm-rock-2);color:var(--mm-fog);}

.mm-prose{
  max-width:68ch;
  line-height:1.85;
}
.mm-prose a{
  color:var(--mm-tundra-deep);
  text-decoration:underline;
  text-decoration-thickness:1px;
  text-underline-offset:3px;
}

.mm-eyebrow{
  display:inline-flex;
  align-items:center;
  gap:9px;
  font-family:var(--mm-font-serif);
  font-size:.76rem;
  font-weight:600;
  letter-spacing:.2em;
  color:var(--mm-tundra);
}
.mm-section--light .mm-eyebrow{color:var(--mm-tundra-deep);}

.mm-num{
  font-family:var(--mm-font-mono);
  font-variant-numeric:tabular-nums;
  font-feature-settings:"tnum" 1;
  letter-spacing:.02em;
}

/* ---------- 网格与卡片 ---------- */
.mm-grid{display:grid;gap:clamp(16px,2.4vw,28px);}
.mm-grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.mm-grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}
.mm-grid--asym{grid-template-columns:minmax(0,5fr) minmax(0,7fr);}

.mm-card{
  position:relative;
  display:flex;
  flex-direction:column;
  gap:12px;
  padding:clamp(18px,2.4vw,26px);
  border:1px solid var(--mm-line);
  border-radius:var(--mm-radius);
  background:linear-gradient(155deg,rgba(44,54,55,.92),rgba(27,34,35,.92));
  color:var(--mm-fog);
}
.mm-card--light{
  background:var(--mm-fog);
  color:var(--mm-char);
  border-color:rgba(16,21,21,.12);
}

/* ---------- 图片容器基础规则 ---------- */
.mm-media{
  position:relative;
  display:block;
  overflow:hidden;
  border-radius:var(--mm-radius);
  aspect-ratio:16 / 9;
  background:
    radial-gradient(120% 120% at 12% 0%,rgba(111,139,98,.42),transparent 62%),
    radial-gradient(110% 110% at 92% 100%,rgba(143,199,217,.34),transparent 60%),
    var(--mm-rock-2);
  isolation:isolate;
}
.mm-media::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(165deg,rgba(27,34,35,0) 42%,rgba(27,34,35,.52));
  pointer-events:none;
}
.mm-media img,
.mm-media picture > img{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
}
.mm-media--wide{aspect-ratio:21 / 9;}
.mm-media--portrait{aspect-ratio:3 / 4;}
.mm-media--square{aspect-ratio:1 / 1;}

/* ---------- 侧边章节索引 ---------- */
.mm-rail{
  display:flex;
  flex-direction:column;
  gap:2px;
  position:sticky;
  top:124px;
}
.mm-rail__link{
  display:block;
  padding:8px 12px;
  border-left:2px solid var(--mm-line);
  font-size:.86rem;
  letter-spacing:.02em;
  color:var(--mm-stone);
  transition:color .16s var(--mm-ease),border-color .16s var(--mm-ease),background-color .16s var(--mm-ease);
}
.mm-rail__link:hover{
  color:var(--mm-fog);
  background:rgba(143,199,217,.08);
}
.mm-rail__link.is-active{
  color:var(--mm-ice);
  border-left-color:var(--mm-lava);
  background:rgba(143,199,217,.1);
}
.mm-section--light .mm-rail__link{
  color:rgba(16,21,21,.62);
  border-left-color:rgba(16,21,21,.14);
}
.mm-section--light .mm-rail__link.is-active{
  color:var(--mm-tundra-deep);
  border-left-color:var(--mm-lava);
  background:rgba(111,139,98,.14);
}

/* ---------- 面包屑 ---------- */
.mm-crumbs{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--mm-font-serif);
  font-size:.78rem;
  letter-spacing:.12em;
  color:var(--mm-stone);
}
.mm-crumbs a{
  border-bottom:1px solid transparent;
  transition:color .16s var(--mm-ease),border-color .16s var(--mm-ease);
}
.mm-crumbs a:hover{color:var(--mm-ice);border-color:currentColor;}
.mm-crumbs__sep{opacity:.42;}
.mm-crumbs [aria-current="page"]{color:var(--mm-fog);}
.mm-section--light .mm-crumbs{color:rgba(16,21,21,.6);}
.mm-section--light .mm-crumbs [aria-current="page"]{color:var(--mm-char);}

/* ---------- 按钮 ---------- */
.mm-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-height:44px;
  padding:0 20px;
  border:0;
  border-radius:999px;
  font-family:var(--mm-font-body);
  font-size:.9rem;
  font-weight:700;
  letter-spacing:.05em;
  line-height:1;
  cursor:pointer;
  transition:background-color .18s var(--mm-ease),color .18s var(--mm-ease),box-shadow .18s var(--mm-ease),transform .18s var(--mm-ease);
}
.mm-btn:active{transform:translateY(1px);}
.mm-btn--lava{
  background:var(--mm-lava);
  color:var(--mm-char);
  box-shadow:0 8px 20px -10px rgba(242,106,46,.95);
}
.mm-btn--lava:hover{background:#ff7d44;}
.mm-btn--ghost{
  background:transparent;
  color:var(--mm-fog);
  box-shadow:inset 0 0 0 1px var(--mm-line-strong);
}
.mm-btn--ghost:hover{color:var(--mm-ice);box-shadow:inset 0 0 0 1px var(--mm-ice);}
.mm-btn--sm{
  min-height:40px;
  padding:0 16px;
  font-size:.84rem;
}

/* ---------- 跳转链接 ---------- */
.mm-skip{
  position:absolute;
  top:-72px;
  left:14px;
  z-index:200;
  padding:12px 18px;
  border-radius:8px;
  background:var(--mm-fog);
  color:var(--mm-char);
  font-size:.86rem;
  font-weight:700;
  letter-spacing:.04em;
  transition:top .2s var(--mm-ease);
}
.mm-skip:focus{top:14px;}

/* ---------- 头部 ---------- */
.mm-header{
  position:sticky;
  top:0;
  z-index:90;
  background:rgba(27,34,35,.9);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid var(--mm-line);
  color:var(--mm-fog);
  transition:background-color .24s var(--mm-ease),box-shadow .24s var(--mm-ease);
}
.mm-header::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:1px;
  background:linear-gradient(90deg,transparent,var(--mm-tundra),var(--mm-ice),transparent);
  opacity:.45;
  pointer-events:none;
}
.mm-header.is-scrolled{
  background:rgba(20,26,27,.97);
  box-shadow:0 18px 32px -28px rgba(0,0,0,.9);
}

.mm-header__inner{
  display:flex;
  align-items:center;
  gap:clamp(10px,1.6vw,22px);
  min-height:68px;
  padding-block:9px;
}

.mm-header__actions{
  display:flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
}

/* 品牌 */
.mm-brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
  min-width:0;
}
.mm-brand__mark{
  width:36px;
  height:36px;
  flex:0 0 auto;
}
.mm-brand__text{display:block;min-width:0;}
.mm-brand__name{
  display:block;
  font-family:var(--mm-font-display);
  font-size:1rem;
  font-weight:900;
  letter-spacing:.07em;
  line-height:1.15;
  color:var(--mm-fog);
}
.mm-brand__sub{
  display:block;
  font-size:.66rem;
  font-weight:500;
  letter-spacing:.16em;
  line-height:1.5;
  color:var(--mm-stone);
  white-space:nowrap;
}
.mm-brand--footer{gap:12px;}
.mm-brand--footer .mm-brand__mark{width:42px;height:42px;}
.mm-brand--footer .mm-brand__name{font-size:1.12rem;}

/* 主导航 */
.mm-nav{margin-left:auto;}
.mm-nav__list{
  display:flex;
  align-items:center;
  gap:clamp(0px,.8vw,10px);
}
.mm-nav__link{
  position:relative;
  display:inline-block;
  padding:9px 10px;
  border-radius:8px;
  font-size:.88rem;
  font-weight:500;
  letter-spacing:.03em;
  color:var(--mm-stone);
  white-space:nowrap;
  transition:color .18s var(--mm-ease),background-color .18s var(--mm-ease);
}
.mm-nav__link:hover{color:var(--mm-fog);background:rgba(242,240,234,.07);}
.mm-nav__link[aria-current="page"]{
  color:var(--mm-fog);
  background:rgba(143,199,217,.12);
}
.mm-nav__link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:10px;
  right:10px;
  bottom:3px;
  height:2px;
  border-radius:2px;
  background:linear-gradient(90deg,var(--mm-tundra),var(--mm-ice));
}

/* 移动导航按钮 */
.mm-navtoggle{
  display:none;
  align-items:center;
  gap:8px;
  min-height:44px;
  padding:0 13px;
  border:1px solid var(--mm-line-strong);
  border-radius:10px;
  background:rgba(242,240,234,.05);
  color:var(--mm-fog);
  font-size:.82rem;
  font-weight:600;
  letter-spacing:.14em;
  cursor:pointer;
  transition:background-color .18s var(--mm-ease),border-color .18s var(--mm-ease);
}
.mm-navtoggle:hover{border-color:var(--mm-ice);}
.mm-navtoggle__bars{display:grid;gap:4px;width:16px;}
.mm-navtoggle__bars span{
  display:block;
  height:2px;
  border-radius:2px;
  background:currentColor;
  transition:transform .22s var(--mm-ease);
}
.mm-navtoggle__label{line-height:1;}

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

/* 快捷索引轨道 */
.mm-indexbar{
  border-top:1px solid rgba(214,208,196,.1);
  background:linear-gradient(90deg,rgba(66,90,69,.36),rgba(27,34,35,0) 52%);
}
.mm-indexbar__inner{
  display:flex;
  align-items:center;
  gap:14px;
  min-height:42px;
  padding-block:7px;
  overflow-x:auto;
  scrollbar-width:none;
}
.mm-indexbar__inner::-webkit-scrollbar{display:none;}
.mm-indexbar__label{
  flex:0 0 auto;
  font-family:var(--mm-font-serif);
  font-size:.74rem;
  font-weight:600;
  letter-spacing:.2em;
  color:var(--mm-tundra);
}
.mm-indexbar__list{
  display:flex;
  align-items:center;
  gap:7px;
  flex:0 0 auto;
}
.mm-indexbar__link{
  display:inline-block;
  padding:5px 13px;
  border:1px solid rgba(214,208,196,.18);
  border-radius:999px;
  font-size:.79rem;
  letter-spacing:.06em;
  color:var(--mm-stone);
  white-space:nowrap;
  transition:color .16s var(--mm-ease),background-color .16s var(--mm-ease),border-color .16s var(--mm-ease);
}
.mm-indexbar__link:hover{
  color:var(--mm-char);
  background:var(--mm-ice);
  border-color:var(--mm-ice);
}
.mm-indexbar__status{
  margin-left:auto;
  flex:0 0 auto;
  display:inline-flex;
  align-items:center;
  gap:8px;
  font-family:var(--mm-font-mono);
  font-size:.71rem;
  letter-spacing:.05em;
  color:var(--mm-ice);
  white-space:nowrap;
}
.mm-dot{
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--mm-lava);
  box-shadow:0 0 0 4px rgba(242,106,46,.2);
}

/* ---------- 页脚 ---------- */
.mm-footer{
  position:relative;
  overflow:hidden;
  background:var(--mm-rock);
  color:var(--mm-fog);
  border-top:1px solid var(--mm-line);
}
.mm-footer::before{
  content:"";
  position:absolute;
  inset:-46% -12% auto -12%;
  height:460px;
  background:
    radial-gradient(58% 100% at 18% 0%,rgba(111,139,98,.3),transparent 72%),
    radial-gradient(52% 100% at 84% 0%,rgba(143,199,217,.17),transparent 70%);
  pointer-events:none;
}
.mm-footer__inner{position:relative;}

.mm-footer__top{
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,1.45fr);
  gap:clamp(28px,5vw,72px);
  padding-block:clamp(42px,6vw,76px) clamp(26px,4vw,44px);
}

.mm-footer__line{
  margin-top:16px;
  max-width:34ch;
  font-size:.94rem;
  line-height:1.8;
  color:var(--mm-stone);
}
.mm-footer__note{
  margin-top:12px;
  font-size:.79rem;
  line-height:1.75;
  color:rgba(214,208,196,.68);
}

.mm-footer__nav{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(18px,3vw,40px);
}
.mm-footer__title{
  margin-bottom:12px;
  font-family:var(--mm-font-serif);
  font-size:.76rem;
  font-weight:600;
  letter-spacing:.22em;
  color:var(--mm-tundra);
}
.mm-footer__list{display:grid;gap:1px;}
.mm-footer__link{
  display:inline-block;
  padding:7px 0;
  font-size:.94rem;
  color:var(--mm-stone);
  transition:color .16s var(--mm-ease),transform .16s var(--mm-ease);
}
.mm-footer__link:hover{color:var(--mm-ice);transform:translateX(3px);}

.mm-footer__meta{
  position:relative;
  display:grid;
  gap:6px;
  padding-block:20px;
  border-top:1px solid var(--mm-line);
}
.mm-footer__contact{
  font-family:var(--mm-font-mono);
  font-size:.8rem;
  letter-spacing:.01em;
  line-height:1.9;
  color:var(--mm-stone);
  overflow-wrap:anywhere;
}

.mm-footer__legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:8px 24px;
  padding-block:18px 30px;
  border-top:1px solid rgba(214,208,196,.1);
  font-size:.78rem;
  letter-spacing:.02em;
  color:rgba(214,208,196,.62);
}

/* 返回顶部 */
.mm-to-top{
  position:fixed;
  right:clamp(14px,3vw,28px);
  bottom:clamp(14px,3vw,28px);
  z-index:80;
  width:48px;
  height:48px;
  display:grid;
  place-items:center;
  border:1px solid var(--mm-line-strong);
  border-radius:50%;
  background:rgba(44,54,55,.94);
  color:var(--mm-fog);
  font-size:1.05rem;
  line-height:1;
  cursor:pointer;
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
  opacity:0;
  visibility:hidden;
  transform:translateY(12px);
  transition:opacity .22s var(--mm-ease),transform .22s var(--mm-ease),visibility .22s var(--mm-ease),background-color .18s var(--mm-ease),color .18s var(--mm-ease);
}
.mm-to-top.is-visible{opacity:1;visibility:visible;transform:none;}
.mm-to-top:hover{background:var(--mm-tundra);color:var(--mm-char);border-color:var(--mm-tundra);}

/* ---------- 平板 ---------- */
@media (max-width:1120px){
  .mm-navtoggle{display:inline-flex;}

  .mm-nav{
    position:absolute;
    inset-inline:0;
    top:100%;
    margin:0;
    display:block;
    padding:12px var(--mm-gutter) 22px;
    background:linear-gradient(180deg,rgba(44,54,55,.99),rgba(27,34,35,.99));
    border-bottom:1px solid var(--mm-line);
    box-shadow:0 26px 44px -28px rgba(0,0,0,.9);
    opacity:0;
    visibility:hidden;
    transform:translateY(-8px);
    transition:opacity .2s var(--mm-ease),transform .2s var(--mm-ease),visibility .2s var(--mm-ease);
    max-height:calc(100vh - 110px);
    overflow-y:auto;
  }
  .mm-nav[data-open]{
    opacity:1;
    visibility:visible;
    transform:none;
  }
  .mm-nav__list{
    flex-direction:column;
    align-items:stretch;
    gap:2px;
  }
  .mm-nav__link{
    display:block;
    padding:14px 14px;
    font-size:1rem;
    border-radius:10px;
    border-bottom:1px solid rgba(214,208,196,.08);
  }
  .mm-nav__link[aria-current="page"]::after{display:none;}
  .mm-nav__link[aria-current="page"]{
    background:rgba(111,139,98,.22);
    box-shadow:inset 3px 0 0 var(--mm-tundra);
  }

  .mm-footer__top{grid-template-columns:1fr;}
  .mm-rail{position:static;top:auto;}
}

/* ---------- 手机 ---------- */
@media (max-width:760px){
  .mm-indexbar__label{display:none;}
  .mm-indexbar__status{display:none;}
  .mm-indexbar__inner{padding-block:9px;gap:10px;}

  .mm-header__inner{min-height:60px;}

  .mm-grid--2,.mm-grid--3,.mm-grid--asym{grid-template-columns:1fr;}

  .mm-footer__nav{grid-template-columns:repeat(2,minmax(0,1fr));gap:22px 20px;}
  .mm-footer__legal{flex-direction:column;align-items:flex-start;}
  .mm-btn--sm{min-height:44px;}
}

@media (max-width:560px){
  .mm-brand__sub{display:none;}
  .mm-brand__name{font-size:.95rem;}
  .mm-brand__mark{width:32px;height:32px;}
  .mm-header__actions{gap:8px;}
  .mm-btn--sm{padding:0 13px;font-size:.8rem;letter-spacing:.03em;}
  .mm-navtoggle{padding:0 11px;letter-spacing:.06em;}
  .mm-footer__nav{grid-template-columns:1fr;}
  .mm-to-top{width:44px;height:44px;}
}

@media (max-width:380px){
  .mm-brand__name{font-size:.88rem;letter-spacing:.03em;}
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
}