/* ============================================================
   明日方舟 · 泰拉群星  -  阅读器样式
   ============================================================ */

/* ---------- 设计变量 ---------- */
:root{
  /* 界面(方舟暗色 + 琥珀点缀) */
  --bg:#0b0c10;
  --bg-2:#101219;
  --panel:rgba(18,21,28,.86);
  --panel-line:rgba(232,147,42,.22);
  --amber:#e8932a;
  --amber-bright:#ffb84a;
  --amber-soft:rgba(232,147,42,.14);
  --text:#d9d3c4;
  --text-dim:#8a8475;
  --text-mute:#5d5749;
  --danger:#d65a3a;

  /* 书页(羊皮纸) */
  --paper:#efe6cf;
  --paper-2:#e7dcc1;
  --paper-edge:#cdbf9c;
  --ink:#2b2620;
  --ink-dim:#6b5f4d;
  --ink-mute:#9a8e76;

  /* 书尺寸(由 JS 设定) */
  --page-w:420px;
  --page-h:560px;
  --page-pad:46px;
  --font-px:18px;
  --book-tilt:3deg;

  /* 翻书光影(由 JS 实时更新) */
  --u-curl:0;       /* 翻动页折弯阴影 */
  --u-sheen:0;      /* 翻动页边缘高光 */
  --u-cast:0;       /* 下方页投影 */
  /* 卷曲几何驱动的折痕/投影方向与位置(未设置时回退旧横排) */
  --fold-a:90deg;   /* 折痕/投影带方向(沿卷轴法向的 CSS 渐变角度) */
  --fold-x:0%;      /* 折痕在翻动页上的横向占比(0=书脊,100%=外边) */
  --fold-lift:0px;  /* 折角抬升近似(供未来投影虚化使用) */
}

/* 深色页面主题 */
body.theme-dark{
  --paper:#1c1e24;
  --paper-2:#16181d;
  --paper-edge:#0e0f13;
  --ink:#d9d3c4;
  --ink-dim:#9a9382;
  --ink-mute:#6d6757;
}

*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  background:var(--bg);
  color:var(--text);
  font-family:"Noto Sans SC","PingFang SC","Microsoft YaHei","微软雅黑",sans-serif;
  -webkit-font-smoothing:antialiased;
  overflow:hidden;
  position:relative;
}
button{font-family:inherit;color:inherit;cursor:pointer;background:none;border:none}
input{font-family:inherit}
.dim{color:var(--text-dim)}
svg{stroke:currentColor;stroke-width:1.8;fill:none;stroke-linecap:round;stroke-linejoin:round}

/* ---------- 背景装饰 ---------- */
.bg-decor{position:fixed;inset:0;z-index:0;pointer-events:none;overflow:hidden}
.bg-grid{
  position:absolute;inset:-2px;
  background-image:
    linear-gradient(rgba(232,147,42,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(232,147,42,.05) 1px,transparent 1px);
  background-size:48px 48px;
  mask-image:radial-gradient(ellipse at 50% 40%,#000 30%,transparent 80%);
  -webkit-mask-image:radial-gradient(ellipse at 50% 40%,#000 30%,transparent 80%);
}
.bg-vignette{
  position:absolute;inset:0;
  background:
    radial-gradient(ellipse at 50% 0%,rgba(232,147,42,.08),transparent 55%),
    radial-gradient(ellipse at 50% 100%,rgba(0,0,0,.55),transparent 60%),
    linear-gradient(180deg,#0b0c10,#070810);
}
.bg-scan{
  position:absolute;inset:0;opacity:.5;
  background:repeating-linear-gradient(0deg,rgba(255,255,255,.012) 0 2px,transparent 2px 4px);
}

/* ---------- 屏幕切换 ---------- */
.screen{position:fixed;inset:0;z-index:1;display:none;flex-direction:column}
.screen--active{display:flex}

/* ============================================================
   图书馆 / 封面
   ============================================================ */
#library{padding:26px 34px 18px}
.lib-header{display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:14px}
.brand-mark{width:42px;height:42px;flex:none}
.brand-mark .mk-ring{stroke:var(--amber);stroke-width:1.6;fill:none}
.brand-mark .mk-core{fill:var(--amber-soft);stroke:var(--amber-bright);stroke-width:1.4}
.brand-mark .mk-line{stroke:var(--amber);stroke-width:1;opacity:.6}
.brand-title{font-size:20px;letter-spacing:.18em;font-weight:600;color:var(--text)}
.brand-sub{font-size:10px;letter-spacing:.32em;color:var(--amber);margin-top:2px}
.lib-stats{font-size:12px;color:var(--text-dim);letter-spacing:.05em;text-align:right}
.lib-stats b{color:var(--amber-bright);font-weight:600}

.lib-main{
  flex:1;display:grid;grid-template-columns:minmax(320px,1fr) minmax(360px,1.1fr);
  gap:30px;padding:22px 0 10px;min-height:0;
}

/* 书封 */
.cover-wrap{display:flex;align-items:center;justify-content:center;min-height:0}
.cover{
  position:relative;width:300px;height:420px;cursor:pointer;
  transform-style:preserve-3d;perspective:1600px;
  transition:transform .5s cubic-bezier(.2,.7,.2,1);
}
.cover:hover{transform:translateY(-6px) rotateY(-8deg)}
.cover:focus-visible{outline:1px solid var(--amber-bright);outline-offset:8px}
.cover-face{
  position:absolute;inset:0;border-radius:3px 7px 7px 3px;
  background:
    linear-gradient(135deg,#1a1410 0%,#241a10 40%,#120d08 100%);
  box-shadow:
    0 30px 60px -20px rgba(0,0,0,.8),
    0 0 0 1px rgba(232,147,42,.25),
    inset 0 0 0 1px rgba(232,147,42,.12);
  overflow:hidden;
}
.cover-front::before{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(circle at 70% 20%,rgba(232,147,42,.18),transparent 50%),
    repeating-linear-gradient(45deg,rgba(232,147,42,.03) 0 2px,transparent 2px 8px);
}
.cover-frame{
  position:absolute;inset:22px;border:1px solid rgba(232,147,42,.35);
  display:flex;flex-direction:column;align-items:center;justify-content:space-between;
  padding:26px 18px;text-align:center;
  clip-path:polygon(0 0,calc(100% - 14px) 0,100% 14px,100% 100%,14px 100%,0 calc(100% - 14px));
}
.cover-tag{font-size:9px;letter-spacing:.4em;color:var(--amber);opacity:.8}
.cover-title{
  font-family:"Noto Serif SC","Source Han Serif SC","Songti SC",serif;
  font-size:46px;font-weight:700;letter-spacing:.12em;color:#f4ead0;
  text-shadow:0 0 24px rgba(232,147,42,.35);line-height:1.1;
}
.cover-rule{width:46px;height:2px;background:linear-gradient(90deg,transparent,var(--amber),transparent)}
.cover-sub{font-size:13px;letter-spacing:.3em;color:#c9bb96}
.cover-mark svg{width:46px;height:46px;opacity:.85}
.cover-mark svg path:first-child{fill:none;stroke:var(--amber);stroke-width:1.4}
.cover-mark svg path:last-child{fill:var(--amber-soft);stroke:var(--amber-bright);stroke-width:1.2}
.cover-foot{font-size:9px;letter-spacing:.18em;color:var(--text-mute)}
.cover-spine{
  position:absolute;left:0;top:0;bottom:0;width:14px;
  background:linear-gradient(90deg,rgba(0,0,0,.6),rgba(0,0,0,.15) 60%,transparent);
  border-right:1px solid rgba(232,147,42,.2);
}
.cover-edge{
  position:absolute;right:-7px;top:4px;bottom:4px;width:7px;
  background:repeating-linear-gradient(90deg,#1a1410,#241a10 1px,#120d08 2px);
  transform:rotateY(40deg);transform-origin:left center;border-radius:0 2px 2px 0;
}
.cover-hint{
  position:absolute;left:50%;bottom:-30px;transform:translateX(-50%);
  font-size:11px;letter-spacing:.3em;color:var(--amber);opacity:.7;
  animation:pulse 2.2s ease-in-out infinite;
}
@keyframes pulse{0%,100%{opacity:.4}50%{opacity:.9}}

/* 目录 */
.toc-panel{
  background:var(--panel);border:1px solid var(--panel-line);
  backdrop-filter:blur(6px);border-radius:4px;padding:18px 20px;
  display:flex;flex-direction:column;min-height:0;
  clip-path:polygon(0 0,calc(100% - 16px) 0,100% 16px,100% 100%,16px 100%,0 calc(100% - 16px));
}
.toc-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:6px}
.toc-title{font-size:12px;letter-spacing:.3em;color:var(--amber)}
.toc-search input{
  background:rgba(0,0,0,.3);border:1px solid var(--panel-line);color:var(--text);
  padding:6px 10px;font-size:12px;border-radius:2px;width:150px;outline:none;
}
.toc-search input:focus{border-color:var(--amber)}
.toc-group{margin-top:12px;min-height:0;display:flex;flex-direction:column}
.toc-group-title{font-size:11px;letter-spacing:.22em;color:var(--text-dim);padding:6px 0;border-bottom:1px solid var(--panel-line);margin-bottom:6px}
.toc-list{overflow-y:auto;max-height:32vh;padding-right:4px}
.toc-list::-webkit-scrollbar{width:6px}
.toc-list::-webkit-scrollbar-thumb{background:var(--amber-soft);border-radius:3px}
.toc-item{
  display:flex;align-items:baseline;gap:10px;padding:7px 10px;border-radius:2px;
  cursor:pointer;transition:background .15s,border-color .15s;
  border-left:2px solid transparent;
}
.toc-item:hover{background:var(--amber-soft);border-left-color:var(--amber)}
.toc-item .ti-no{font-size:11px;color:var(--amber);font-variant-numeric:tabular-nums;min-width:26px}
.toc-item .ti-name{font-size:14px;color:var(--text);flex:1}
.toc-item .ti-meta{font-size:10px;color:var(--text-mute)}
.toc-item.empty{display:none}

.lib-footer{display:flex;justify-content:space-between;font-size:11px;color:var(--text-mute);letter-spacing:.05em;padding-top:8px}

/* ============================================================
   阅读器
   ============================================================ */
#reader{display:none}
#reader.screen--active{display:flex}

/* 顶栏 */
.topbar{
  display:flex;align-items:center;gap:14px;padding:10px 18px;
  border-bottom:1px solid var(--panel-line);background:rgba(11,12,16,.7);backdrop-filter:blur(8px);
  z-index:5;
}
.topbar-titles{flex:1;min-width:0;text-align:center}
.topbar-arc{font-size:13px;color:var(--text);letter-spacing:.08em;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-section{font-size:11px;color:var(--amber);letter-spacing:.12em;margin-top:1px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar-actions{display:flex;gap:6px}

/* 按钮 */
.btn{display:inline-flex;align-items:center;justify-content:center;border-radius:2px;transition:all .15s;color:var(--text)}
.btn-icon{width:34px;height:34px;border:1px solid var(--panel-line)}
.btn-icon:hover{border-color:var(--amber);color:var(--amber-bright);background:var(--amber-soft)}
.btn-icon svg{width:18px;height:18px}
.btn-mini{padding:6px 12px;font-size:12px;border:1px solid var(--panel-line);letter-spacing:.08em}
.btn-mini:hover{border-color:var(--amber);color:var(--amber-bright)}
.btn-toggle{min-width:84px}

/* 舞台 */
/* FIX: perspective-origin now matches the WebGL camera, which projects the book
   bounding-box center onto the stage center. 50% 42% made the CSS fallback fold
   from a different vanish point than the WebGL curl, drifting edges mid-animation. */
.stage{flex:1;position:relative;display:flex;align-items:center;justify-content:center;min-height:0;perspective:2400px;perspective-origin:50% 50%}
.stage-loader{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;z-index:8;background:radial-gradient(circle at 50% 50%,rgba(11,12,16,.4),rgba(11,12,16,.9))}
.stage-loader.hidden{display:none}
.loader-ring{width:42px;height:42px;border:2px solid var(--amber-soft);border-top-color:var(--amber);border-radius:50%;animation:spin 1s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.loader-txt{font-size:12px;letter-spacing:.2em;color:var(--text-dim)}

/* ---------- 3D 书 ---------- */
.book-scene{
  position:relative;transform-style:preserve-3d;
  transform:rotateX(var(--book-tilt));
  transition:transform .4s ease;
}
.book{
  position:relative;width:calc(var(--page-w)*2);height:var(--page-h);
  transform-style:preserve-3d;
}
.page{position:absolute;top:0;width:var(--page-w);height:var(--page-h);transform-style:preserve-3d}
.page--left{left:0}
.page--right{left:var(--page-w)}

.page-paper{
  position:absolute;inset:0;background:var(--paper);
  background-image:
    radial-gradient(circle at 30% 12%,rgba(255,255,255,.5),transparent 40%),
    radial-gradient(circle at 80% 90%,rgba(120,90,40,.06),transparent 50%),
    linear-gradient(135deg,var(--paper) 0%,var(--paper-2) 100%);
  box-shadow:inset 0 0 60px rgba(120,90,40,.07);
  overflow:hidden;
  border-radius:0 2px 2px 0;
}
.page--left .page-paper{border-radius:2px 0 0 2px;
  background-image:
    radial-gradient(circle at 70% 12%,rgba(255,255,255,.5),transparent 40%),
    radial-gradient(circle at 20% 90%,rgba(120,90,40,.06),transparent 50%),
    linear-gradient(225deg,var(--paper) 0%,var(--paper-2) 100%);
}
.page-inner{
  position:absolute;inset:0;padding:var(--page-pad);
  padding-top:calc(var(--page-pad)*.7);padding-bottom:calc(var(--page-pad)*.7);
  overflow:hidden;
  font-family:"Noto Serif SC","Source Han Serif SC","Songti SC","STSong","SimSun",serif;
  font-size:var(--font-px);line-height:1.92;color:var(--ink);
  letter-spacing:.01em;
  column-fill:auto;
}
.page-folio{
  position:absolute;bottom:14px;font-size:11px;color:var(--ink-mute);
  font-family:"Noto Sans SC",sans-serif;letter-spacing:.1em;font-variant-numeric:tabular-nums;
}
.page--left .page-folio,.face--back .page-folio{left:18px}
.page--right .page-folio,.face--front .page-folio{right:18px}

/* 翻动页 */
.page--flip{
  left:var(--page-w);transform-origin:left center;
  transform:rotateY(0deg);
  z-index:30;will-change:transform;
}
.page--flip.flip--left{left:0;transform-origin:right center}
/* FIX: .face must not clip -- it is a transformed 3D wrapper whose children move
   through space; overflow:hidden on it sheared the backface into diagonal crop
   triangles around 90 deg. Clipping stays on the physical .page-paper boundary. */
.face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;transform-style:preserve-3d}
/* FIX: separate the two coplanar faces by paper half-thickness so they cannot
   z-fight at 90 deg. rotateY(180deg) then translateZ(+t) places the back face at
   global z=-t while the front face sits at +t. */
.face--front{transform:rotateY(0deg) translateZ(0.35px)}
.face--back{transform:rotateY(180deg) translateZ(0.35px)}
.face .page-paper{border-radius:2px}

/* 翻动页光影(折线:折痕处最深,外侧高光) */
.face--front::after,.face--back::after{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:5;
  transition:none;
}
/* 折痕:1px 高光 + 深阴影带,位置跟随卷轴(--fold-x),方向沿折痕线(--fold-a) */
.face--front::after{background:linear-gradient(var(--fold-a,90deg),
  rgba(255,250,235,.05) 0,rgba(255,250,235,.05) 1px,
  rgba(0,0,0,var(--u-curl)) calc(var(--fold-x,0%) + 2px),
  rgba(0,0,0,calc(var(--u-curl)*.5)) calc(var(--fold-x,0%) + 12%),
  rgba(0,0,0,0) calc(var(--fold-x,0%) + 55%))}
.face--back::after{background:linear-gradient(var(--fold-a,-90deg),
  rgba(255,250,235,.05) 0,rgba(255,250,235,.05) 1px,
  rgba(0,0,0,var(--u-curl)) calc(var(--fold-x,0%) + 2px),
  rgba(0,0,0,calc(var(--u-curl)*.5)) calc(var(--fold-x,0%) + 12%),
  rgba(0,0,0,0) calc(var(--fold-x,0%) + 55%))}
.face--front::before,.face--back::before{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:4;
}
/* 外侧边缘高光(被翻起的一侧受光) */
.face--front::before{background:linear-gradient(to right,transparent 55%,rgba(255,250,235,var(--u-sheen)) 100%)}
.face--back::before{background:linear-gradient(to left,transparent 55%,rgba(255,250,235,var(--u-sheen)) 100%)}

/* 下方页投影(折页投在书脊一侧,随折起强度变化) */
.page--right::before,.page--left::before{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:6;opacity:0;transition:opacity .1s;
}
.book--forward .page--right::before{background:linear-gradient(var(--fold-a,90deg),
  rgba(0,0,0,.45) calc(var(--fold-x,0%) + 2px),
  rgba(0,0,0,.15) calc(var(--fold-x,0%) + 18%),
  transparent calc(var(--fold-x,0%) + 70%));opacity:var(--u-cast)}
.book--backward .page--left::before{background:linear-gradient(var(--fold-a,-90deg),
  rgba(0,0,0,.45) calc(var(--fold-x,0%) + 2px),
  rgba(0,0,0,.15) calc(var(--fold-x,0%) + 18%),
  transparent calc(var(--fold-x,0%) + 70%));opacity:var(--u-cast)}

/* 悬停预览:纯 CSS 折角/边缘提示(页面保持平整,不翘起;翻页由点击触发) */
.book.peek-right .page--right::after,
.book.peek-left .page--left::after{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:7;
  background:linear-gradient(var(--peek-a,225deg),rgba(0,0,0,.15),transparent 24%);
  animation:peekIn .25s ease;
}
/* 单页模式左半悬停:`.page--left` 隐藏,折角提示落在唯一可见的 `.page--right` 上 */
body.mode-single .book.peek-left .page--right::after{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:7;
  background:linear-gradient(var(--peek-a,135deg),rgba(0,0,0,.15),transparent 24%);
  animation:peekIn .25s ease;
}
@keyframes peekIn{from{opacity:0}to{opacity:1}}

/* 书脊 */
.spine{
  position:absolute;left:var(--page-w);top:0;bottom:0;width:10px;margin-left:-5px;
  background:linear-gradient(90deg,rgba(0,0,0,.5),rgba(0,0,0,.12) 45%,rgba(0,0,0,.12) 55%,rgba(0,0,0,.5));
  z-index:25;pointer-events:none;
}

/* 页堆边(厚度) */
.page-stack{position:absolute;top:4px;bottom:4px;width:8px;z-index:1;pointer-events:none}
.page-stack--right{
  left:calc(var(--page-w)*2);
  background:repeating-linear-gradient(90deg,var(--paper-edge),var(--paper) 1px,var(--paper-edge) 2px,var(--paper-2) 3px);
  transform:rotateY(28deg);transform-origin:left center;border-radius:0 3px 3px 0;
  box-shadow:1px 0 3px rgba(0,0,0,.3);
}
.page-stack--left{
  left:-8px;
  background:repeating-linear-gradient(90deg,var(--paper-2),var(--paper-edge) 1px,var(--paper) 2px,var(--paper-edge) 3px);
  transform:rotateY(-28deg);transform-origin:right center;border-radius:3px 0 0 3px;
  box-shadow:-1px 0 3px rgba(0,0,0,.3);
}

/* 书的地面投影 */
.book-cast{
  position:absolute;left:-4%;right:-4%;bottom:-26px;height:40px;
  background:radial-gradient(ellipse at 50% 0%,rgba(0,0,0,.55),transparent 70%);
  filter:blur(6px);z-index:0;pointer-events:none;
}

/* WebGL 曲面翻页画布:覆盖舞台,翻页时由 JS 显示 */
.flip-canvas{
  position:absolute;inset:0;width:100%;height:100%;
  z-index:30;pointer-events:none;display:none;
}
/* WebGL 模式下隐藏 CSS 翻动页(由 canvas 接管) */
.book--gl .page--flip{display:none !important}

/* 热区(点击/悬停翻页) */
.hotzone{position:absolute;top:0;bottom:0;width:22%;z-index:15;cursor:grab;touch-action:none}
.hotzone:active{cursor:grabbing}
.hotzone--right{right:0}
.hotzone--left{left:0}

/* 翻书交互:禁止滚动/手势捕获,拖拽时全局抓手光标 */
.stage,.book{touch-action:none}
body.book-dragging{cursor:grabbing}

/* 翻页箭头 */
.nav-arrow{
  position:absolute;top:50%;transform:translateY(-50%);z-index:31;
  /* 31 > 画布(30):翻页时导航按钮仍在卷曲面上方,不被整幅画布遮挡 */
  width:40px;height:56px;display:flex;align-items:center;justify-content:center;
  border:1px solid var(--panel-line);background:rgba(11,12,16,.6);color:var(--text-dim);
  border-radius:2px;transition:all .15s;
}
.nav-arrow:hover{color:var(--amber-bright);border-color:var(--amber);background:rgba(232,147,42,.12)}
.nav-arrow svg{width:20px;height:20px}
.nav-arrow--prev{left:14px}
.nav-arrow--next{right:14px}
.nav-arrow:disabled{opacity:.25;cursor:default}

/* 底栏(点击穿透:书的上下边可能溢出舞台到底栏区域,角落要能点击翻页) */
.bottombar{padding:10px 22px 14px;border-top:1px solid var(--panel-line);background:rgba(11,12,16,.7);backdrop-filter:blur(8px);z-index:5;pointer-events:none}
.bottombar .progress-wrap{pointer-events:auto}
.progress-wrap{max-width:780px;margin:0 auto}
.progress-track{position:relative;height:4px;background:rgba(255,255,255,.08);border-radius:2px;cursor:pointer}
.progress-fill{position:absolute;left:0;top:0;bottom:0;background:linear-gradient(90deg,var(--amber),var(--amber-bright));border-radius:2px;width:0}
.progress-thumb{position:absolute;top:50%;width:12px;height:12px;background:var(--amber-bright);border-radius:50%;transform:translate(-50%,-50%);box-shadow:0 0 0 3px rgba(232,147,42,.2);left:0}
.progress-meta{display:flex;justify-content:space-between;margin-top:6px;font-size:11px;color:var(--text-dim);letter-spacing:.08em;font-variant-numeric:tabular-nums}

/* 抽屉(本卷目录) */
.drawer-overlay{position:fixed;inset:0;background:rgba(0,0,0,.55);backdrop-filter:blur(2px);z-index:40;opacity:0;pointer-events:none;transition:opacity .25s}
.drawer-overlay.open{opacity:1;pointer-events:auto}
.drawer{
  position:fixed;top:0;right:0;bottom:0;width:340px;max-width:86vw;z-index:41;
  background:var(--bg-2);border-left:1px solid var(--panel-line);
  transform:translateX(100%);transition:transform .3s cubic-bezier(.2,.7,.2,1);
  display:flex;flex-direction:column;
}
.drawer.open{transform:translateX(0)}
.drawer-head{display:flex;align-items:center;justify-content:space-between;padding:14px 16px;border-bottom:1px solid var(--panel-line);font-size:13px;letter-spacing:.16em;color:var(--amber)}
.drawer-body{flex:1;overflow-y:auto;padding:10px 12px}
.drawer-body::-webkit-scrollbar{width:6px}
.drawer-body::-webkit-scrollbar-thumb{background:var(--amber-soft);border-radius:3px}
.drawer-item{padding:10px 12px;border-radius:2px;cursor:pointer;border-left:2px solid transparent;transition:background .15s}
.drawer-item:hover{background:var(--amber-soft);border-left-color:var(--amber)}
.drawer-item.active{background:var(--amber-soft);border-left-color:var(--amber-bright)}
.drawer-item .di-title{font-size:13px;color:var(--text)}
.drawer-item .di-meta{font-size:10px;color:var(--text-mute);margin-top:2px}

/* 字号面板 */
.font-panel{
  position:fixed;top:60px;right:16px;z-index:42;
  background:var(--bg-2);border:1px solid var(--panel-line);border-radius:3px;
  padding:12px;display:none;flex-direction:column;gap:10px;min-width:200px;
  box-shadow:0 12px 30px rgba(0,0,0,.5);
}
.font-panel.open{display:flex}
.font-row{display:flex;align-items:center;gap:8px}
.font-label{font-size:11px;color:var(--text-dim);letter-spacing:.12em;width:36px}
.font-val{font-size:13px;color:var(--amber-bright);min-width:24px;text-align:center;font-variant-numeric:tabular-nums}

/* ============================================================
   书页内容排版
   ============================================================ */
.runner{
  display:flex;justify-content:space-between;align-items:baseline;
  font-family:"Noto Sans SC",sans-serif;font-size:10px;letter-spacing:.14em;
  color:var(--ink-mute);margin-bottom:14px;padding-bottom:6px;
  border-bottom:1px solid rgba(120,90,40,.18);
}
.runner .r-arc::before{content:"❖ ";color:var(--amber-dim)}
.sec-title{
  font-family:"Noto Serif SC",serif;font-size:calc(var(--font-px)*1.4);font-weight:700;
  color:var(--ink);letter-spacing:.06em;line-height:1.4;
  margin:6px 0 18px;padding-bottom:10px;
  border-bottom:1px solid rgba(120,90,40,.2);
  position:relative;
}
.sec-title::before{content:"";position:absolute;left:0;bottom:-1px;width:36px;height:2px;background:var(--amber)}

.dlg{margin:0 0 .42em;text-indent:0}
.dlg-name{
  font-family:"Noto Sans SC",sans-serif;font-weight:600;font-size:calc(var(--font-px)*.82);
  color:var(--amber);letter-spacing:.04em;margin-right:.5em;
  display:inline-block;
}
.dlg-name::after{content:"";display:inline-block;width:.4em}
.dlg-text{color:var(--ink)}

.nar{margin:0 0 .6em;text-indent:2em;text-align:justify;color:var(--ink)}
.cap{
  font-family:"Noto Sans SC",sans-serif;font-size:calc(var(--font-px)*.74);
  color:var(--ink-dim);letter-spacing:.1em;text-align:center;
  margin:.8em auto;padding:4px 12px;opacity:.85;
}

/* 封面/标题页 */
.page-cover{
  height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;
  text-align:center;gap:14px;padding:30px;
}
.page-cover .pc-tag{font-family:"Noto Sans SC",sans-serif;font-size:10px;letter-spacing:.4em;color:var(--amber)}
.page-cover .pc-title{font-family:"Noto Serif SC",serif;font-size:calc(var(--font-px)*2.1);font-weight:700;color:var(--ink);letter-spacing:.1em;line-height:1.2}
.page-cover .pc-rule{width:60px;height:2px;background:var(--amber)}
.page-cover .pc-sub{font-family:"Noto Sans SC",sans-serif;font-size:calc(var(--font-px)*.78);color:var(--ink-dim);letter-spacing:.2em}
.page-cover .pc-meta{font-size:calc(var(--font-px)*.68);color:var(--ink-mute);letter-spacing:.1em;margin-top:8px}

/* ============================================================
   响应式 / 单页模式
   ============================================================ */
body.mode-single .page--left,
body.mode-single .spine,
body.mode-single .page-stack--left{display:none}
body.mode-single .book{width:var(--page-w)}
body.mode-single .page--right{left:0}
body.mode-single .page--flip{left:0;transform-origin:left center}
body.mode-single .page--flip.flip--left{left:0;transform-origin:right center}
body.mode-single .book-scene{transform:rotateX(0deg)}

/* ============================================================
   翻页进度光带(屏幕左右边缘细长高光,翻页中可视化)
   ============================================================ */
.flip-rail{
  position:absolute;top:0;bottom:0;width:6px;z-index:18;pointer-events:none;
  opacity:0;transition:opacity .12s ease;
  background:linear-gradient(180deg,transparent 8%,var(--amber-bright) 50%,transparent 92%);
  box-shadow:0 0 16px var(--amber-bright),0 0 4px var(--amber);
  filter:blur(.4px);
}
.flip-rail--left{left:0;border-radius:0 3px 3px 0}
.flip-rail--right{right:0;border-radius:3px 0 0 3px}

/* 沉浸模式(双击空白区切换):隐藏顶栏/底栏,书本体铺满。
   用 #reader 限定提升 specificity,确保胜过 #reader .topbar 等通用选择器。*/
body.immersive #reader .topbar,
body.immersive #reader .bottombar,
body.immersive #reader .nav-arrow{display:none}
body.immersive #reader{padding:0}
body.immersive .stage{padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left)}

/* ============================================================
   移动端响应式优化(平板/手机/小屏)
   断点:1024 / 820 / 768 / 480
   ============================================================ */

/* 1024 - 平板/小屏笔记本:藏侧栏,书封居中 */
@media (max-width:1024px){
  #library{padding:18px 22px}
  .lib-main{grid-template-columns:1fr;gap:18px;align-items:start}
  .cover-wrap{padding:20px 0 6px}
  .toc-panel{max-height:60vh}
}

/* 820 - 平板竖屏:进入单页模式(已由 JS 自动处理),UI 收紧 */
@media (max-width:820px){
  #library{padding:14px 14px 18px}
  .lib-main{grid-template-columns:1fr;gap:14px;padding:8px 0 6px}
  .cover{width:200px;height:280px}
  .cover-title{font-size:32px}
  .cover-frame{inset:16px;padding:18px 12px}
  .cover-mark svg{width:36px;height:36px}
  .toc-list{max-height:48vh}
  /* 翻页按钮缩小但保留(贴边,半透明),不粗暴藏起 */
  .nav-arrow{
    width:36px;height:48px;
    background:rgba(11,12,16,.42);
    border-color:rgba(232,147,42,.18);
  }
  .nav-arrow--prev{left:6px}
  .nav-arrow--next{right:6px}
  .topbar{padding:8px 10px;gap:6px;overflow:hidden}
  .topbar-titles{padding:0 4px;min-width:0}
  .topbar-arc{font-size:12px;letter-spacing:.04em}
  .topbar-section{font-size:10px}
  .topbar-actions{gap:4px;flex-shrink:0}
  .btn-icon{width:38px;height:38px;flex-shrink:0}
  .btn-icon svg{width:20px;height:20px}
  /* safe area:适配 iPhone 刘海/灵动岛/底栏 */
  #reader{padding-top:env(safe-area-inset-top);padding-bottom:env(safe-area-inset-bottom)}
  .topbar{padding-left:max(10px,env(safe-area-inset-left));padding-right:max(10px,env(safe-area-inset-right))}
  .bottombar{padding-left:max(14px,env(safe-area-inset-left));padding-right:max(14px,env(safe-area-inset-right))}
  /* 进度条加粗便于触摸 */
  .progress-track{height:6px}
  .progress-thumb{width:16px;height:16px}
  /* 抽屉更宽更像 sheet */
  .drawer{width:88vw;max-width:88vw}
  /* 字号面板:手机上变成底部 sheet */
  .font-panel{
    top:auto;bottom:max(20px,env(safe-area-inset-bottom));right:0;left:0;
    margin:0 14px;min-width:0;width:auto;border-radius:6px;
  }
  /* 热区扩到屏幕 28% */
  .hotzone{width:28%}
  /* 输入框 16px 防 iOS 缩放 */
  .toc-search input{font-size:16px;width:100%}
  /* 翻页光带略宽 */
  .flip-rail{width:8px}
}

/* 480 - 小屏手机(竖屏) */
@media (max-width:520px){
  #library{padding:12px}
  .lib-stats{display:none}
  .brand-title{font-size:15px;letter-spacing:.12em}
  .brand-sub{font-size:8px}
  .cover{width:170px;height:238px}
  .cover-title{font-size:26px;letter-spacing:.08em}
  .cover-tag,.cover-sub,.cover-foot{font-size:8px;letter-spacing:.18em}
  .cover-rule{width:34px;height:1.5px}
  .cover-frame{inset:14px;padding:14px 10px}
  .toc-panel{padding:14px 14px}
  .toc-title{font-size:11px;letter-spacing:.22em}
  .toc-group-title{font-size:10px}
  .toc-item{padding:8px 10px}
  .toc-item .ti-name{font-size:13px}
  .lib-footer{font-size:10px}
  /* 顶栏更紧凑;section 标题隐藏(避免挤压按钮) */
  .topbar{padding:6px 8px;gap:4px;overflow:hidden}
  .topbar-titles{padding:0 4px;min-width:0}
  .topbar-arc{font-size:11px;letter-spacing:.02em;max-width:60vw}
  .topbar-section{display:none}
  .topbar-actions{gap:3px;flex-shrink:0}
  .btn-icon{width:34px;height:34px;flex-shrink:0}
  .btn-icon svg{width:18px;height:18px}
  /* 翻页按钮进一步缩小 */
  .nav-arrow{width:30px;height:42px}
  .nav-arrow--prev{left:4px}
  .nav-arrow--next{right:4px}
  .nav-arrow svg{width:16px;height:16px}
  /* 进度条 meta 字号小 */
  .progress-meta{font-size:10px}
  /* 抽屉全屏 */
  .drawer{width:100vw;max-width:100vw}
}

/* 360 - 极小屏 */
@media (max-width:360px){
  .cover{width:148px;height:206px}
  .cover-title{font-size:22px}
  .nav-arrow{width:28px;height:40px}
}

/* 横屏(手机横屏/iPad 横屏):书可以双页,但顶栏底栏占空间小 */
@media (max-width:900px) and (orientation:landscape){
  .bottombar{padding:6px 12px 8px}
  .topbar{padding:6px 10px}
}

/* ============================================================
   减弱动态效果:禁用卷曲/回弹动画,翻页由 JS 走瞬时换页
   ============================================================ */
@media (prefers-reduced-motion: reduce){
  *,
  *::before,
  *::after{
    animation-duration:.001s !important;
    animation-iteration-count:1 !important;
    transition-duration:.001s !important;
    scroll-behavior:auto !important;
  }
  /* 悬停折角提示瞬时显隐,不播 peekIn 动画 */
  .book.peek-right .page--right::after,
  .book.peek-left .page--left::after,
  body.mode-single .book.peek-left .page--right::after{animation:none}
  /* 翻动页/画布相关过渡全部失效 */
  .page--flip{transition:none !important}
  .flip-canvas{display:none !important}
  .book--gl .page--flip{display:none !important}
  .flip-rail{display:none !important}
  /* 减弱态下不进沉浸 */
  body.immersive .topbar,
  body.immersive .bottombar{display:flex}
}