/* ============================================================
   口琴曲谱 —— 极简黑白
   背景纯白 · 文字纯黑 · 只用细线分区
   ============================================================ */

:root{
  --ink:#000;
  --ink-2:rgba(0,0,0,.55);
  --ink-3:rgba(0,0,0,.38);
  --line:#e6e6e6;
  --line-strong:#000;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --serif:"Iowan Old Style","Palatino Linotype",Georgia,"Songti SC","SimSun","Times New Roman",serif;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Consolas,"Courier New",monospace;
  --pad:26px;
  --ease:cubic-bezier(.2,.6,.2,1);
}

*,*::before,*::after{box-sizing:border-box}
[hidden]{display:none!important}

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

body{
  margin:0;
  min-height:100vh;
  display:grid;
  grid-template-columns:clamp(238px,25%,360px) minmax(0,1fr);
  background:#fff;
  color:var(--ink);
  font-family:var(--sans);
  font-size:14px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

::selection{background:#000;color:#fff}

:focus-visible{outline:1px solid #000;outline-offset:2px}

a{color:inherit}

/* ─────────── 左侧栏 ─────────── */

.side{
  position:sticky;
  top:0;
  height:100vh;
  min-height:100vh;
  display:flex;
  flex-direction:column;
  gap:26px;
  padding:30px var(--pad) 20px;
  border-right:1px solid var(--line);
  overflow-y:auto;
  overscroll-behavior:contain;
}

.brand{margin:0}
.brand h1{
  margin:0;
  font-family:var(--serif);
  font-size:20px;
  font-weight:500;
  letter-spacing:.03em;
  line-height:1.25;
}
.brand-sub{
  margin:8px 0 0;
  font-size:9px;
  letter-spacing:.26em;
  text-transform:uppercase;
  color:var(--ink-2);
}

.label{
  display:block;
  margin:0 0 10px;
  font-size:10px;
  font-weight:400;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--ink-2);
}

.field,.block{margin:0;min-width:0}

.input{
  width:100%;
  padding:9px 10px;
  border:1px solid var(--line-strong);
  border-radius:0;
  background:#fff;
  color:var(--ink);
  font:inherit;
  font-size:13px;
  -webkit-appearance:none;
  appearance:none;
}
.input::placeholder{color:var(--ink-3)}
.input:hover{border-color:#000}
.input:focus{outline:none;box-shadow:inset 0 0 0 1px #000}

.select{
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='9' height='6'%3E%3Cpath d='M0 0l4.5 6L9 0' fill='none' stroke='%23000' stroke-width='1'/%3E%3C/svg%3E");
  background-repeat:no-repeat;
  background-position:right 11px center;
  padding-right:28px;
  cursor:pointer;
}

/* 标签筛选 */
.tags{display:flex;flex-wrap:wrap;gap:6px}
.tag{
  padding:4px 9px;
  border:1px solid var(--line);
  border-radius:0;
  background:#fff;
  color:var(--ink);
  font:inherit;
  font-size:11.5px;
  line-height:1.4;
  cursor:pointer;
  transition:border-color .16s var(--ease),background-color .16s var(--ease),color .16s var(--ease);
}
.tag:hover{border-color:#000}
.tag[aria-pressed="true"]{background:#000;border-color:#000;color:#fff}

/* 设置行 */
.row{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  min-height:30px;
  font-size:12.5px;
}
.row-ctl{display:flex;align-items:center;gap:10px;flex:1;justify-content:flex-end}
.row-ctl output{
  min-width:38px;
  text-align:right;
  font-family:var(--mono);
  font-size:11px;
  color:var(--ink-2);
}
input[type="range"]{
  -webkit-appearance:none;
  appearance:none;
  width:100%;
  max-width:120px;
  height:16px;
  background:transparent;
  cursor:pointer;
  accent-color:#000;
}
input[type="range"]::-webkit-slider-runnable-track{height:1px;background:#000}
input[type="range"]::-webkit-slider-thumb{
  -webkit-appearance:none;
  width:11px;height:11px;
  margin-top:-5px;
  border-radius:50%;
  background:#000;
}
input[type="range"]::-moz-range-track{height:1px;background:#000}
input[type="range"]::-moz-range-thumb{
  width:11px;height:11px;border:0;border-radius:50%;background:#000;
}
input[type="checkbox"]{
  -webkit-appearance:none;
  appearance:none;
  width:15px;height:15px;
  margin:0;
  border:1px solid #000;
  background:#fff;
  cursor:pointer;
  position:relative;
  flex:none;
}
input[type="checkbox"]:checked{background:#000}
input[type="checkbox"]:checked::after{
  content:"";
  position:absolute;left:4px;top:1px;
  width:5px;height:9px;
  border:solid #fff;
  border-width:0 1.5px 1.5px 0;
  transform:rotate(45deg);
}

/* 侧栏底部 */
.side-foot{
  margin-top:auto;
  padding-top:16px;
  border-top:1px solid var(--line);
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:10px;
}
.count{font-size:11px;letter-spacing:.1em;color:var(--ink-2)}
.link{
  border:0;background:none;padding:0;
  font:inherit;font-size:11px;
  letter-spacing:.1em;
  color:var(--ink);
  text-decoration:underline;
  text-underline-offset:3px;
  text-decoration-thickness:1px;
  cursor:pointer;
}

/* ─────────── 右侧舞台 ─────────── */

.stage{
  min-width:0;
  min-height:100vh;
  display:flex;
  flex-direction:column;
}

.stage-bar{
  position:sticky;
  top:0;
  z-index:20;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
  padding:15px 32px;
  background:#fff;
  border-bottom:1px solid var(--line);
}
.crumb{
  font-size:11.5px;
  letter-spacing:.16em;
  text-transform:none;
  color:var(--ink-2);
  overflow:hidden;
  text-overflow:ellipsis;
  white-space:nowrap;
}
.crumb b{font-weight:500;color:#000;letter-spacing:.08em}
.stage-actions{display:flex;align-items:center;gap:20px;flex:none}
.btn{
  border:0;background:none;padding:0;
  font:inherit;font-size:11.5px;
  letter-spacing:.1em;
  color:var(--ink);
  cursor:pointer;
  text-decoration:none;
  white-space:nowrap;
}
.btn:hover{text-decoration:underline;text-underline-offset:3px}
.btn[disabled]{color:var(--ink-3);cursor:default;text-decoration:none}

.stage-body{
  flex:1;
  min-width:0;
  padding:30px 32px 90px;
}

/* ─────────── 曲谱列表 ─────────── */

.grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(178px,1fr));
  gap:30px 22px;
  align-content:start;
}
.card{
  display:block;
  text-align:left;
  border:0;
  padding:0;
  background:none;
  color:inherit;
  font:inherit;
  cursor:pointer;
  min-width:0;
}
.thumb{
  position:relative;
  aspect-ratio:3/4;
  border:1px solid var(--line);
  background:#fff;
  overflow:hidden;
  transition:border-color .18s var(--ease);
}
.card:hover .thumb,
.card:focus-visible .thumb{border-color:#000}
.thumb img{
  display:block;
  width:100%;height:100%;
  object-fit:cover;
  object-position:top center;
  filter:grayscale(1);
  transition:filter .2s var(--ease);
}
.card:hover .thumb img{filter:grayscale(0)}
.thumb .kind{
  position:absolute;
  left:0;bottom:0;
  padding:2px 6px;
  background:#000;
  color:#fff;
  font-size:9px;
  letter-spacing:.16em;
  text-transform:uppercase;
}
.thumb .pages{
  position:absolute;
  right:6px;top:5px;
  font-family:var(--mono);
  font-size:10px;
  color:var(--ink-2);
}
.thumb.placeholder{
  display:flex;
  align-items:center;
  justify-content:center;
}
.thumb.placeholder span{
  font-family:var(--serif);
  font-size:20px;
  letter-spacing:.1em;
}
.card .title{
  margin:10px 0 0;
  font-size:13px;
  line-height:1.45;
  overflow:hidden;
  display:-webkit-box;
  -webkit-line-clamp:2;
  -webkit-box-orient:vertical;
}
.card .meta{
  margin:4px 0 0;
  font-size:10px;
  letter-spacing:.12em;
  text-transform:none;
  color:var(--ink-2);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

/* 紧凑列表 */
.grid.dense{grid-template-columns:1fr;gap:0}
.grid.dense .card{
  display:grid;
  grid-template-columns:38px minmax(0,1fr) auto;
  align-items:center;
  gap:16px;
  padding:11px 2px;
  border-bottom:1px solid var(--line);
}
.grid.dense .card:hover{background:#fff}
.grid.dense .thumb{
  width:38px;
  aspect-ratio:3/4;
  border-color:var(--line);
}
.grid.dense .thumb .kind,
.grid.dense .thumb .pages{display:none}
.grid.dense .card .title{margin:0;font-size:13.5px;-webkit-line-clamp:1}
.grid.dense .card .meta{margin:0;text-align:right}

/* ─────────── 查看器 ─────────── */

.viewer{--zoom:1;overflow-x:auto;overflow-y:hidden}
.viewer .page{
  width:calc(var(--zoom) * 100%);
  margin:0 auto 26px;
  border:1px solid var(--line);
  background:#fff;
}
.viewer[data-fit="off"] .page{width:calc(var(--zoom) * 820px)}
.viewer .page img{
  display:block;
  width:100%;
  height:auto;
}
.viewer .page .pagenum{
  display:block;
  padding:6px 10px;
  border-top:1px solid var(--line);
  font-family:var(--mono);
  font-size:10px;
  letter-spacing:.14em;
  color:var(--ink-2);
  text-align:right;
}
.viewer iframe.pdf{
  display:block;
  width:100%;
  height:calc(100vh - 168px);
  min-height:520px;
  border:1px solid var(--line);
  background:#fff;
}
.viewer .missing{
  padding:60px 24px;
  border:1px solid var(--line);
  text-align:center;
  font-size:13px;
  line-height:2;
}

/* ─────────── 空状态 ─────────── */

.empty{max-width:620px;padding:56px 0 0}
.empty h2{
  margin:0 0 18px;
  font-family:var(--serif);
  font-size:27px;
  font-weight:400;
  letter-spacing:.04em;
  line-height:1.4;
}
.empty p{margin:0 0 12px;line-height:1.95;font-size:13.5px;color:var(--ink)}
.empty .dim{color:var(--ink-2);font-size:12.5px}
.empty ol{margin:14px 0 0;padding-left:1.3em;line-height:2}
.empty code{
  font-family:var(--mono);
  font-size:11.5px;
  padding:1px 5px;
  border:1px solid var(--line);
  white-space:nowrap;
}
.empty hr{
  height:1px;border:0;
  background:var(--line);
  margin:28px 0;
}

/* ─────────── 滚动条 ─────────── */

.side::-webkit-scrollbar,
.viewer::-webkit-scrollbar,
.stage-body::-webkit-scrollbar{width:9px;height:9px}
.side::-webkit-scrollbar-thumb,
.viewer::-webkit-scrollbar-thumb,
.stage-body::-webkit-scrollbar-thumb{background:rgba(0,0,0,.18)}
.side::-webkit-scrollbar-thumb:hover,
.viewer::-webkit-scrollbar-thumb:hover{background:rgba(0,0,0,.4)}
.side::-webkit-scrollbar-track,
.viewer::-webkit-scrollbar-track{background:#fff}

/* ─────────── 窄屏 ─────────── */

@media (max-width:860px){
  body{grid-template-columns:1fr}
  .side{
    position:static;
    height:auto;
    min-height:0;
    border-right:0;
    border-bottom:1px solid var(--line);
    padding:24px 20px 18px;
    gap:20px;
  }
  .side-foot{margin-top:4px}
  .stage-bar{padding:13px 20px}
  .stage-body{padding:22px 20px 70px}
  .grid{grid-template-columns:repeat(auto-fill,minmax(132px,1fr));gap:24px 16px}
  .viewer iframe.pdf{height:72vh}
}

@media (prefers-reduced-motion:reduce){
  *{transition:none!important;animation:none!important}
}

/* ─────────── 打印：只打曲谱 ─────────── */

@media print{
  .side,.stage-bar{display:none}
  body{display:block}
  .stage-body{padding:0}
  .grid,.empty{display:none}
  .viewer{--zoom:1}
  .viewer .page{width:100%;border:0;margin:0 0 12px;page-break-after:always}
}

/* ─────────── 谱种切换 / 待放入 ─────────── */

.btn.is-active{
  text-decoration:underline;
  text-underline-offset:3px;
  text-decoration-thickness:1px;
}
.actions-gap{
  display:inline-block;
  width:1px;
  height:12px;
  background:var(--line);
  vertical-align:middle;
}
.thumb.pending{border-style:dashed}

.viewer .missing{text-align:left;line-height:2.1}
.viewer .missing b{font-weight:500}
.viewer .missing code{
  font-family:var(--mono);
  font-size:11.5px;
  padding:1px 5px;
  border:1px solid var(--line);
  white-space:nowrap;
}

.thumb.pending .kind{
  top:50%;
  left:50%;
  right:auto;
  bottom:auto;
  transform:translate(-50%,-50%);
  background:#fff;
  color:var(--ink-2);
  font-size:10px;
  letter-spacing:.24em;
}

/* ─────────── 左下角：回到主站 ─────────── */

.home-link{
  display:block;
  margin-top:14px;
  padding:9px 10px;
  border:1px solid #000;
  background:#000;
  color:#fff;
  font-size:12px;
  letter-spacing:.08em;
  text-align:center;
  text-decoration:none;
  transition:background-color .16s var(--ease), color .16s var(--ease);
}
.home-link:hover,
.home-link:focus-visible{
  background:#fff;
  color:#000;
}

@media print{.home-link{display:none}}