:root{
  --paper:#fbfaf7;
  --ink:#1c1a19;
  --ui:#1c1a19;
  --line:rgba(28,26,24,.10);
  --bar-bg:rgba(255,255,255,.78);
  --safe-t:env(safe-area-inset-top,0px);
  --safe-b:env(safe-area-inset-bottom,0px);
  --hdr-h:52px;
  /* 画板主题 */
  --board-bg:#fbfaf7;
  --board-rule:rgba(28,26,24,.06);
  --board-ink:#1c1a19;
}
:root[data-theme="chalk"]{
  --board-bg:#22282e;
  --board-rule:rgba(255,255,255,.07);
  --board-ink:#f2efe8;
}

*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{height:100%}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--paper);color:var(--ink);
  font:400 15px/1.6 -apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  overscroll-behavior:none;touch-action:manipulation;
  -webkit-user-select:none;user-select:none;
  overflow:hidden;
}
button{font-family:inherit}

/* ---------------- 顶栏 ---------------- */
.top{
  position:fixed;top:0;left:0;right:0;height:calc(var(--hdr-h) + var(--safe-t));
  padding:var(--safe-t) 12px 0;
  display:flex;align-items:center;gap:10px;z-index:30;
  background:var(--bar-bg);backdrop-filter:saturate(180%) blur(14px);
  -webkit-backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:7px;text-decoration:none;color:var(--ink);flex:0 0 auto}
.mark{
  width:26px;height:26px;border-radius:8px;background:var(--ink);color:var(--paper);
  display:grid;place-items:center;font-size:15px;font-weight:600;line-height:1;
}
.brand-txt{font-size:14px;font-weight:600;letter-spacing:.01em;white-space:nowrap}

.modes{
  position:relative;margin:0 auto;display:flex;padding:3px;border-radius:999px;
  background:rgba(28,26,24,.07);
}
.modes button{
  position:relative;z-index:2;appearance:none;border:0;background:transparent;
  padding:5px 15px;border-radius:999px;font-size:13px;font-weight:500;color:rgba(28,26,24,.55);
  cursor:pointer;transition:color .18s ease;
}
.modes button[aria-selected="true"]{color:var(--ink)}
.mode-slider{
  position:absolute;z-index:1;top:3px;bottom:3px;left:3px;width:calc(50% - 3px);
  background:#fff;border-radius:999px;box-shadow:0 1px 3px rgba(28,26,24,.14);
  transition:transform .22s cubic-bezier(.4,0,.2,1);
}
.modes[data-mode="write"] .mode-slider{transform:translateX(100%)}

.top-right{display:flex;gap:2px;flex:0 0 auto}
.icon-btn{
  appearance:none;border:0;background:transparent;color:var(--ui);
  width:34px;height:34px;border-radius:999px;display:grid;place-items:center;
  cursor:pointer;padding:0;text-decoration:none;transition:background .15s ease,transform .1s ease;
}
.icon-btn:hover{background:rgba(28,26,24,.06)}
.icon-btn:active{transform:scale(.92)}
.icon-btn svg{width:19px;height:19px;display:block}
.icon-btn.on{background:rgba(28,26,24,.11)}
.icon-btn[disabled]{opacity:.28;pointer-events:none}

/* ---------------- 视图 ---------------- */
.view{position:fixed;inset:var(--hdr-h) 0 0 0;top:calc(var(--hdr-h) + var(--safe-t))}
.view[hidden]{display:none!important}
/* 黑板主题：画板整屏换成深色 */
#boardView{background:var(--board-bg);transition:background .2s ease}
.layer{position:absolute;inset:0;width:100%;height:100%;display:block;touch-action:none}
#boardBg{pointer-events:none}

/* ---------------- 工具栏 ---------------- */
.toolbar{
  position:absolute;left:50%;transform:translateX(-50%);
  bottom:calc(10px + var(--safe-b));
  display:flex;align-items:center;gap:2px;padding:5px 7px;border-radius:999px;
  background:var(--bar-bg);border:1px solid var(--line);
  box-shadow:0 6px 24px rgba(28,26,24,.12);
  backdrop-filter:saturate(180%) blur(14px);-webkit-backdrop-filter:saturate(180%) blur(14px);
  z-index:20;max-width:calc(100vw - 16px);
}
.toolbar button{width:36px;height:36px}
.toolbar svg{width:19px;height:19px}
.pill{
  appearance:none;border:0;background:transparent;color:var(--ui);cursor:pointer;
  height:34px;padding:0 13px;border-radius:999px;font-size:13px;font-weight:500;
  transition:background .15s ease,transform .1s ease;white-space:nowrap;
}
.pill:active{transform:scale(.94)}
.pill.strong{background:var(--ink);color:var(--paper)}
.pill.strong:active{background:rgba(28,26,24,.82)}
.sep{width:1px;height:20px;background:var(--line);margin:0 4px;flex:0 0 auto}
.dots{display:flex;gap:3px;padding:0 3px}
.dot{
  width:21px;height:21px;border-radius:50%;border:1.5px solid rgba(28,26,24,.16);
  cursor:pointer;padding:0;transition:transform .12s ease,box-shadow .12s ease;
}
.dot.on{transform:scale(1.15);box-shadow:0 0 0 2px var(--paper),0 0 0 3.5px currentColor}
.dot:active{transform:scale(.95)}
#bSize{font-size:12px;font-weight:600}

/* ---------------- 写字模式 ---------------- */
#writeView{display:flex;flex-direction:column;background:var(--paper)}
.body{
  flex:1 1 auto;min-height:0;overflow-y:auto;-webkit-overflow-scrolling:touch;
  padding:18px 18px 40px;outline:none;
  font-family:"Ma Shan Zheng","Caveat",cursive;
  font-size:19px;line-height:2;
  background-image:repeating-linear-gradient(to bottom,transparent 0,transparent 37px,var(--board-rule) 37px,var(--board-rule) 38px);
  background-position:0 22px;
  user-select:text;-webkit-user-select:text;
  caret-color:var(--ink);
}
.body:empty::before{content:"在这里写点什么…";color:rgba(28,26,24,.26);font-family:-apple-system,system-ui,sans-serif;font-size:15px}
.body .ink{display:inline-block;vertical-align:-.22em;line-height:1;margin:0 .02em}
.body .ink svg{display:block;height:1.05em;width:auto;overflow:visible}
.body .ink path{fill:var(--ink)}
.body .ind{display:inline-block;width:2em}

.padwrap{
  flex:0 0 auto;border-top:1px solid var(--line);background:#fff;
  padding-bottom:var(--safe-b);
}
.pad-status{
  display:flex;align-items:center;gap:8px;padding:7px 14px 0;
  font-size:12.5px;color:rgba(28,26,24,.5);min-height:26px;
}
.pad-hint{flex:1 1 auto;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* 标点建议条 */
.pad-suggest{
  display:flex;align-items:center;gap:6px;flex-wrap:wrap;
  padding:7px 12px 2px;
}
.pad-suggest[hidden]{display:none}
.suggest-tip{font-size:12px;color:rgba(28,26,24,.5);flex:0 0 auto}
.suggest-btn{
  appearance:none;border:1px solid rgba(28,26,24,.18);background:#fff;
  border-radius:10px;padding:5px 11px;cursor:pointer;
  display:flex;align-items:center;gap:7px;line-height:1;
  box-shadow:0 1px 2px rgba(28,26,24,.06);
  transition:background .14s ease,transform .1s ease,border-color .14s ease;
}
.suggest-btn:hover{border-color:rgba(28,26,24,.3)}
.suggest-btn:active{transform:scale(.96);background:#f4f1ea}
.suggest-btn b{
  font-size:24px;font-weight:400;line-height:1;
  font-family:"Ma Shan Zheng","Caveat",cursive;color:var(--ink);
  display:inline-block;min-width:1.1em;text-align:center;
}
.suggest-btn i{font-style:normal;font-size:11px;color:rgba(28,26,24,.58);white-space:nowrap}
.suggest-x{
  appearance:none;border:1px solid transparent;background:transparent;cursor:pointer;
  font-size:12px;color:rgba(28,26,24,.5);padding:5px 8px;border-radius:8px;
}
.suggest-x:hover{background:rgba(28,26,24,.05)}

.pad-canvas-wrap{position:relative;height:132px;margin:4px 10px 2px}
#padBg{pointer-events:none}
.pad-canvas-wrap::after{
  content:"";position:absolute;left:10px;right:10px;bottom:22px;height:1px;
  background:rgba(28,26,24,.10);pointer-events:none;
}
#writeView .toolbar{position:relative;bottom:auto;left:auto;transform:none;margin:0 auto 10px}

/* ---------------- 弹窗 ---------------- */
.modal{
  position:fixed;inset:0;z-index:60;display:grid;place-items:center;padding:24px;
  background:rgba(251,250,247,.9);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
}
.modal[hidden]{display:none}
.modal-card{
  position:relative;max-width:320px;width:100%;background:#fff;border:1px solid var(--line);
  border-radius:20px;padding:26px 22px 20px;text-align:center;
  box-shadow:0 16px 48px rgba(28,26,24,.14);
}
.modal-card h2{margin:0 0 6px;font-size:17px;font-weight:600}
.modal-card p{margin:0 0 16px;font-size:13.5px;color:rgba(28,26,24,.58)}
.modal-x{
  position:absolute;top:10px;right:10px;appearance:none;border:0;background:transparent;
  color:rgba(28,26,24,.4);width:30px;height:30px;border-radius:999px;cursor:pointer;
  display:grid;place-items:center;
}
.modal-x svg{width:16px;height:16px}
.qr-box{
  display:grid;place-items:center;padding:12px;background:#fff;
  border:1px solid var(--line);border-radius:14px;
}
.qr-box svg{width:200px;height:200px;display:block}
.qr-url{
  display:block;margin-top:12px;font-size:11px;color:rgba(28,26,24,.45);
  word-break:break-all;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;
}

/* ---------------- 提示条 ---------------- */
#toast{
  position:fixed;left:50%;transform:translate(-50%,8px);bottom:calc(76px + var(--safe-b));
  background:rgba(28,26,24,.9);color:#fff;font-size:13px;padding:8px 14px;border-radius:999px;
  opacity:0;pointer-events:none;transition:opacity .22s ease,transform .22s ease;z-index:70;white-space:nowrap;
}
#toast.show{opacity:1;transform:translate(-50%,0)}

@media (max-width:430px){
  .brand-txt{display:none}
  .toolbar{gap:0;padding:4px 5px}
  .toolbar button{width:33px;height:33px}
  .toolbar svg{width:18px;height:18px}
  .pill{padding:0 11px;font-size:12.5px}
  .sep{margin:0 3px;height:18px}
  .dot{width:19px;height:19px}
  .dots{gap:2px;padding:0 2px}
  .body{font-size:18px;padding:14px 14px 30px}
  .pad-canvas-wrap{height:118px}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}