:root{
  --bg:#f3f6fb;--panel:#fff;--panel2:#f8fafc;--text:#111827;--muted:#6b7280;--line:#e5e7eb;
  --blue:#2563eb;--blue-soft:#eef4ff;--hover:#f3f4f6;--code:#0f172a;--code-text:#e2e8f0;
  --shadow:0 12px 36px rgba(15,23,42,.12)
}
html[data-theme="dark"]{
  --bg:#0b1020;--panel:#111827;--panel2:#172033;--text:#e5e7eb;--muted:#94a3b8;--line:#263247;
  --blue:#60a5fa;--blue-soft:#13233d;--hover:#1b2639;--code:#090f1d;--code-text:#e2e8f0;
  --shadow:0 14px 40px rgba(0,0,0,.36)
}

*{box-sizing:border-box}
html,body{height:100%;min-height:100%;margin:0}
body{
  font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--text)
}
button,input,textarea{font:inherit;color:inherit}
button{cursor:pointer}
.app{height:100vh;height:100dvh;min-height:0;display:flex;flex-direction:column;overflow:hidden}

/* ---------- 单行顶部栏 ---------- */
.navbar{
  height:54px;
  min-height:54px;
  border-bottom:1px solid var(--line);
  background:var(--panel);
  display:flex;
  align-items:center;
  gap:10px;
  padding:0 14px;
  flex:none;
  position:relative;
  z-index:20;
}

.filename-wrap{
  width:280px;
  min-width:180px;
  flex:0 1 280px;
}
.filename{
  width:100%;
  height:36px;
  border:1px solid var(--line);
  background:var(--panel2);
  border-radius:8px;
  padding:0 12px;
  font-weight:700;
  outline:none;
  transition:border-color .15s,box-shadow .15s,background .15s;
}
.filename:focus{
  border-color:var(--blue);
  box-shadow:0 0 0 3px color-mix(in srgb,var(--blue) 14%,transparent);
}

.nav-group{display:flex;align-items:center;gap:2px;flex:none}
.nav-item{position:relative}
.navbtn{
  height:36px;
  border:0;
  background:transparent;
  padding:0 10px;
  border-radius:7px;
  white-space:nowrap;
}
.navbtn:hover,.navbtn.open{background:var(--hover)}

.menu{
  position:absolute;
  top:43px;
  left:0;
  min-width:220px;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:11px;
  box-shadow:var(--shadow);
  padding:6px;
  display:none;
  z-index:100;
}
.menu.open{display:block}
.menu button{
  width:100%;
  border:0;
  background:transparent;
  border-radius:7px;
  padding:9px 10px;
  text-align:left;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.menu button:hover{background:var(--hover)}
.menu .sep-line{height:1px;background:var(--line);margin:5px 4px}
.kbd{font-size:11px;color:var(--muted)}

.spacer{flex:1;min-width:12px}

.modes{
  height:100%;
  display:flex;
  align-items:stretch;
  gap:1px;
  flex:none;
}
.modebtn{
  min-width:52px;
  border:0;
  background:transparent;
  padding:0 10px;
  border-bottom:2px solid transparent;
  color:var(--muted);
  white-space:nowrap;
}
.modebtn:hover{background:var(--hover);color:var(--text)}
.modebtn.active{color:var(--blue);border-color:var(--blue);font-weight:700}

.theme-btn{
  width:36px;
  height:36px;
  flex:none;
  display:grid;
  place-items:center;
  border:1px solid var(--line);
  background:var(--panel);
  border-radius:8px;
  font-size:17px;
}
.theme-btn:hover{background:var(--hover)}

/* ---------- 编辑区 ---------- */
.workspace{
  flex:1;
  min-height:0;
  display:grid;
  grid-template-columns:1fr 1fr;
  background:var(--bg)
}
.pane{min-width:0;min-height:0;background:var(--panel);overflow:auto}
.editor-pane{position:relative;border-right:1px solid var(--line)}
.editor{
  width:100%;height:100%;
  border:0;resize:none;outline:none;
  padding:22px 24px 80px;
  background:var(--panel);color:var(--text);
  font:15px/1.7 "SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;
  tab-size:2
}

.preview-pane{padding:26px 36px 80px}
.preview{max-width:900px;margin:auto;line-height:1.75;font-size:16px}
.preview h1{font-size:30px;margin:0 0 20px}
.preview h2{font-size:22px;margin-top:28px}
.preview h3{font-size:18px;margin-top:24px}
.preview p{margin:9px 0}
.preview blockquote{
  margin:16px 0;padding:8px 15px;
  border-left:3px solid var(--blue);
  background:var(--blue-soft);
  color:var(--muted)
}
.preview code{background:var(--panel2);padding:2px 5px;border-radius:5px}
.preview pre{
  background:var(--code);color:var(--code-text);
  padding:16px 18px;border-radius:9px;overflow:auto
}
.preview pre code{background:transparent;padding:0}
.preview img{max-width:100%;border-radius:10px}
.preview table{width:100%;border-collapse:collapse;margin:18px 0}
.preview td,.preview th{border:1px solid var(--line);padding:8px 10px}
.preview a{color:var(--blue)}

.drop-overlay{
  position:absolute;inset:18px;
  border:2px dashed var(--blue);
  border-radius:14px;
  background:color-mix(in srgb,var(--blue-soft) 92%,transparent);
  display:none;
  place-items:center;
  text-align:center;
  font-weight:700;
  color:var(--blue);
  z-index:5
}
.editor-pane.dragging .drop-overlay{display:grid}
.drop-overlay small{display:block;color:var(--muted);font-weight:500;margin-top:8px}

/* ---------- 底部状态栏 ---------- */
.statusbar{
  height:34px;
  border-top:1px solid var(--line);
  background:var(--panel);
  display:flex;
  align-items:center;
  padding:0 16px;
  gap:16px;
  color:var(--muted);
  font-size:12px;
  flex:none
}
.dot{width:8px;height:8px;border-radius:50%;background:#10b981}
.status-right{margin-left:auto;display:flex;gap:16px}

/* ---------- 模式 ---------- */
.workspace.single{grid-template-columns:1fr}
.workspace.single .preview-pane{display:none}
.workspace.wysiwyg-mode{grid-template-columns:1fr}
.workspace.wysiwyg-mode .editor-pane{display:none}
.workspace.wysiwyg-mode .preview-pane{display:block}
.workspace.preview-only{grid-template-columns:1fr}
.workspace.preview-only .editor-pane{display:none}
.workspace.code-mode{grid-template-columns:1fr}
.workspace.code-mode .preview-pane{display:none}
.workspace.code-mode .editor{background:var(--code);color:var(--code-text)}

/* ---------- 通用控件 ---------- */
.btn{
  border:1px solid var(--line);
  background:var(--panel);
  border-radius:9px;
  padding:9px 12px;
  display:inline-flex;
  align-items:center;
  gap:7px
}
.btn:hover{background:var(--hover)}

.modal{
  position:fixed;inset:0;
  background:rgba(0,0,0,.42);
  display:none;
  align-items:center;
  justify-content:center;
  z-index:300
}
.modal.open{display:flex}
.card{
  width:min(480px,calc(100vw - 32px));
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:15px;
  box-shadow:var(--shadow);
  padding:20px
}
.card h3{margin:0 0 14px}
.field{margin:10px 0}
.field label{display:block;font-size:12px;color:var(--muted);margin-bottom:5px}
.field input{
  width:100%;
  border:1px solid var(--line);
  background:var(--panel2);
  border-radius:8px;
  padding:10px 11px;
  outline:none
}
.card-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}

.image-manager{max-height:340px;overflow:auto;border:1px solid var(--line);border-radius:10px}
.image-row{
  display:grid;
  grid-template-columns:52px 1fr auto;
  gap:10px;
  align-items:center;
  padding:9px;
  border-bottom:1px solid var(--line)
}
.image-row:last-child{border-bottom:0}
.image-row img{width:52px;height:42px;object-fit:cover;border-radius:6px;background:var(--panel2)}
.image-meta{min-width:0}
.image-name{font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.image-size{font-size:11px;color:var(--muted)}
.image-actions{display:flex;gap:5px;align-items:center;flex-wrap:wrap}
.image-width-control{display:flex;align-items:center;gap:4px}
.image-width-input{
  width:62px;height:32px;
  border:1px solid var(--line);
  background:var(--panel2);
  border-radius:6px;
  padding:0 6px;
  text-align:center;
}
.image-width-unit{font-size:12px;color:var(--muted)}
.mini{border:1px solid var(--line);background:var(--panel);border-radius:6px;padding:5px 7px}

.toast{
  position:fixed;right:18px;bottom:52px;
  background:var(--text);color:var(--panel);
  padding:9px 12px;border-radius:8px;
  opacity:0;transform:translateY(8px);
  transition:.2s;pointer-events:none;z-index:500
}
.toast.show{opacity:1;transform:none}
.hidden{display:none!important}

/* ---------- 平板 ---------- */
@media(max-width:1050px) and (min-width:821px){
  .navbar{gap:6px;padding:0 10px}
  .filename-wrap{width:220px;flex-basis:220px}
  .navbtn{padding:0 8px}
  .modebtn{min-width:auto;padding:0 8px}
}

/* ---------- 手机端 ---------- */
@media(max-width:820px){
  html,body{overscroll-behavior:none}
  body{-webkit-text-size-adjust:100%}

  .app{
    height:100dvh;
    min-height:100dvh;
  }

  /* 手机顶部采用两行紧凑布局：
     第一行文件名 + 主题，第二行五个主菜单。 */
  .navbar{
    height:auto;
    min-height:96px;
    flex-wrap:wrap;
    align-content:center;
    gap:6px 8px;
    padding:
      max(6px,env(safe-area-inset-top))
      8px
      7px;
    overflow:visible;
  }

  .filename-wrap{
    order:1;
    width:auto;
    min-width:0;
    flex:1 1 calc(100% - 46px);
  }

  .filename{
    height:36px;
    font-size:16px; /* 防止 iOS 聚焦时自动放大 */
    padding:0 10px;
  }

  .theme-btn{
    order:2;
    width:36px;
    height:36px;
  }

  .nav-group{
    order:3;
    width:100%;
    flex:1 0 100%;
    display:grid;
    grid-template-columns:repeat(5,minmax(0,1fr));
    gap:2px;
  }

  .nav-item{position:static}

  .navbtn{
    width:100%;
    height:34px;
    padding:0 2px;
    font-size:14px;
    text-align:center;
    overflow:hidden;
    text-overflow:ellipsis;
  }

  /* 移动端菜单固定在顶部栏下方，避免被横向容器裁剪。 */
  .menu{
    position:fixed;
    top:calc(max(96px, 84px + env(safe-area-inset-top)));
    left:8px;
    right:8px;
    width:auto;
    min-width:0;
    max-height:min(62dvh,520px);
    overflow:auto;
    -webkit-overflow-scrolling:touch;
    border-radius:12px;
  }

  .menu button{
    min-height:44px;
    padding:10px 12px;
    font-size:15px;
  }

  .kbd{font-size:10px}

  .spacer{display:none}

  /* 手机上不做左右分屏，模式切换放到底部，节省顶部空间。 */
  .modes{
    position:fixed;
    left:8px;
    right:8px;
    bottom:max(8px,env(safe-area-inset-bottom));
    height:48px;
    z-index:180;
    padding:4px;
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:3px;
    background:color-mix(in srgb,var(--panel) 94%,transparent);
    border:1px solid var(--line);
    border-radius:13px;
    box-shadow:var(--shadow);
    backdrop-filter:blur(12px);
    -webkit-backdrop-filter:blur(12px);
  }

  .modebtn{
    min-width:0;
    height:38px;
    padding:0 8px;
    border:0;
    border-radius:9px;
    font-size:14px;
  }

  .modebtn.active{
    border:0;
    background:var(--blue-soft);
  }

  .modebtn[data-mode="split"]{display:none}

  .workspace{
    grid-template-columns:1fr;
    min-height:0;
  }

  /* “分屏”状态在手机上等同于编辑状态，防止空白页。 */
  .workspace .preview-pane{display:none}
  .workspace.wysiwyg-mode .editor-pane{display:none}
  .workspace.wysiwyg-mode .preview-pane{display:block}
  .workspace.preview-only .editor-pane{display:none}
  .workspace.preview-only .preview-pane{display:block}
  .workspace.single .editor-pane{display:block}
  .workspace.code-mode .editor-pane{display:block}

  .editor-pane{border-right:0}
  .editor{
    padding:16px 14px calc(92px + env(safe-area-inset-bottom));
    font-size:16px; /* iOS textarea 不缩放 */
    line-height:1.65;
  }

  .preview-pane{
    padding:18px 16px calc(92px + env(safe-area-inset-bottom));
  }

  .preview{
    max-width:none;
    font-size:16px;
    line-height:1.72;
    overflow-wrap:anywhere;
    word-break:break-word;
  }

  .preview h1{font-size:26px;margin-bottom:16px}
  .preview h2{font-size:21px;margin-top:24px}
  .preview h3{font-size:18px}
  .preview pre{
    margin-left:-4px;
    margin-right:-4px;
    max-width:calc(100vw - 24px);
    overflow-x:auto;
    -webkit-overflow-scrolling:touch;
  }

  .preview table{
    display:block;
    width:100%;
    max-width:100%;
    overflow-x:auto;
    -webkit-overflow-scrolling:touch;
  }

  .preview img{
    height:auto;
    max-width:100%;
  }

  .drop-overlay{inset:10px}

  /* 手机端隐藏状态栏，信息已由编辑区和本地保存承担。 */
  .statusbar{display:none}

  /* 弹窗改为底部抽屉，更适合单手操作和软键盘。 */
  .modal{
    align-items:flex-end;
    padding:0;
  }

  .card{
    width:100%;
    max-height:86dvh;
    overflow:auto;
    border-radius:16px 16px 0 0;
    border-left:0;
    border-right:0;
    border-bottom:0;
    padding:18px 16px calc(18px + env(safe-area-inset-bottom));
  }

  .field input{
    min-height:44px;
    font-size:16px;
  }

  .card-actions{
    position:sticky;
    bottom:0;
    background:var(--panel);
    padding-top:10px;
  }

  .card-actions .btn{
    min-height:42px;
  }

  .image-manager{
    max-height:52dvh;
  }

  .image-row{
    grid-template-columns:48px minmax(0,1fr);
    gap:8px;
  }

  .image-row img{
    width:48px;
    height:42px;
  }

  .image-actions{
    grid-column:1 / -1;
    justify-content:flex-end;
  }
  .image-width-input{width:58px}

  .mini{
    min-height:36px;
    padding:7px 10px;
  }

  .toast{
    left:50%;
    right:auto;
    bottom:calc(68px + env(safe-area-inset-bottom));
    transform:translate(-50%,8px);
    max-width:calc(100vw - 32px);
    text-align:center;
    white-space:normal;
  }

  .toast.show{transform:translate(-50%,0)}
}

/* 特别窄的手机 */
@media(max-width:390px){
  .navbar{padding-left:6px;padding-right:6px}
  .navbtn{font-size:13px}
  .filename{font-size:15px}
  .menu{left:6px;right:6px}
}

/* 横屏手机：尽量减少顶部占用 */
@media(max-width:900px) and (orientation:landscape){
  .navbar{
    min-height:78px;
    padding-top:max(4px,env(safe-area-inset-top));
    padding-bottom:4px;
  }

  .filename-wrap{flex-basis:calc(100% - 44px)}
  .navbtn{height:30px}
  .menu{top:calc(78px + env(safe-area-inset-top))}
  .modes{
    left:auto;
    width:270px;
  }
}

/* ---------- 打印 ---------- */
@media print{
  html[data-theme="dark"]{
    --panel:#fff;--text:#111827;--muted:#64748b;--line:#ddd;--panel2:#f8fafc
  }
  .navbar,.statusbar,.editor-pane{display:none!important}
  .app{height:auto;overflow:visible}
  .workspace{display:block}
  .preview-pane{display:block!important;overflow:visible;padding:0}
  .preview{max-width:none}
}


/* ---------- 所见即所得编辑模式 ---------- */
.workspace.wysiwyg-mode .preview-pane{background:var(--panel)}
.workspace.wysiwyg-mode .preview{min-height:100%;outline:none;caret-color:var(--blue)}
.workspace.wysiwyg-mode .preview:focus{outline:none}
.workspace.wysiwyg-mode .preview img{cursor:zoom-in;outline:1px dashed transparent;outline-offset:4px}
.workspace.wysiwyg-mode .preview img:hover{outline-color:var(--blue)}
.workspace.wysiwyg-mode .preview table{cursor:text}
.workspace.wysiwyg-mode .preview [contenteditable="false"]{user-select:none}