/* ============================================================
   YCat 全站统一左侧导航 Rail（共享组件）
   使用：页面引入本 CSS + js/app-rail.js，body 内放 <div id="app-rail"></div>
   机制：rail 固定左侧；非编辑器页靠 body 左 padding 随 --rail-w 联动；
        编辑器页（含 #editor-app）自动加 .editor-page 类，padding 归零、由自身 .main 处理左移。
   ============================================================ */
:root{
  --rail-bg: #11142b;
  --rail-bg-2: #171b38;
  --rail-fg: #c9cdec;
  --rail-fg-dim: #7e85b4;
  --rail-active: #8b7bff;
  --rail-active-soft: rgba(139,123,255,.18);
  --rail-hover: rgba(255,255,255,.055);
  --rail-edge: rgba(255,255,255,.07);
  --rail-w: 66px;
  --rail-w-expanded: 216px;
  --rail-font: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
}

/* —— 页面容器联动：非编辑器页面用 body 左 padding —— */
body.has-rail{ padding-left: var(--rail-w); transition: padding-left .24s cubic-bezier(.4,0,.2,1); }
body.has-rail.rail-expanded{ --rail-w: var(--rail-w-expanded); }
body.has-rail.editor-page{ padding-left: 0; } /* 编辑器自行管理 .main 位移 */

/* —— Rail 容器（深色常驻，修复收起变白） —— */
#app-rail{
  position: fixed; left: 0; top: 0; bottom: 0;
  width: var(--rail-w);
  display: flex; flex-direction: column;
  background: linear-gradient(180deg,var(--rail-bg),var(--rail-bg-2));
  color: var(--rail-fg);
  border-right: 1px solid var(--rail-edge);
  z-index: 600;
  transition: width .24s cubic-bezier(.4,0,.2,1);
  font-family: var(--rail-font);
  overflow: hidden;
  user-select: none;
}
body.rail-expanded #app-rail{ width: var(--rail-w-expanded); }

/* 收起态：细微内阴影暗示“可展开”，不再覆盖背景 */
body:not(.rail-expanded) #app-rail{
  box-shadow: inset 14px 0 22px -18px rgba(139,123,255,.5);
}

/* Logo */
#app-rail .rail-logo{
  flex: 0 0 auto;
  height: 56px; display: flex; align-items: center; gap: 11px;
  padding: 0 16px; margin: 0;
  font-weight: 800; font-size: 15px; letter-spacing: .3px;
  color: #fff; text-decoration: none;
  border-bottom: 1px solid var(--rail-edge);
}
#app-rail .rail-logo::before{
  content: "Y"; flex: 0 0 auto;
  width: 30px; height: 30px; border-radius: 9px;
  display: grid; place-items: center;
  background: linear-gradient(135deg,#7c5cff,#4f46e5 55%,#6450e6);
  color: #fff; font-size: 17px; font-weight: 800;
  box-shadow: 0 4px 14px rgba(79,70,229,.45);
}
#app-rail .rail-logo .rail-logo-text{ display: none; white-space: nowrap; }
body.rail-expanded #app-rail .rail-logo .rail-logo-text{ display: inline; }

/* Toggle */
#app-rail .rail-toggle{
  flex: 0 0 auto;
  display: flex; align-items: center; gap: 10px;
  height: 40px; margin: 10px; padding: 0 11px;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--rail-edge);
  border-radius: 10px;
  color: var(--rail-fg); cursor: pointer;
  transition: background .16s ease, transform .12s ease;
}
#app-rail .rail-toggle:hover{ background: rgba(255,255,255,.09); }
#app-rail .rail-toggle:active{ transform: scale(.97); }
#app-rail .rail-toggle .rt-chev{
  flex: 0 0 auto; width: 18px; height: 18px;
  transition: transform .24s cubic-bezier(.4,0,.2,1);
}
body.rail-expanded #app-rail .rail-toggle .rt-chev{ transform: rotate(180deg); }
#app-rail .rail-toggle .rt-label{ display: none; font-size: 13px; white-space: nowrap; }
body.rail-expanded #app-rail .rail-toggle .rt-label{ display: inline; }

/* Scroll area */
#app-rail .rail-scroll{
  flex: 1 1 auto;
  overflow-y: auto; overflow-x: hidden;
  padding: 4px 10px 16px;
  display: flex; flex-direction: column; gap: 4px;
  scrollbar-width: thin; scrollbar-color: rgba(255,255,255,.14) transparent;
}
#app-rail .rail-scroll::-webkit-scrollbar{ width: 7px; }
#app-rail .rail-scroll::-webkit-scrollbar-thumb{ background: rgba(255,255,255,.14); border-radius: 8px; }

/* Group */
#app-rail .rail-group{ display: flex; flex-direction: column; gap: 2px; }
#app-rail .rail-group + .rail-group{ margin-top: 6px; padding-top: 8px; border-top: 1px solid rgba(255,255,255,.05); }

/* Group head（可点击收缩，仅展开态可见） */
#app-rail .rail-group-head{
  display: none;
  align-items: center; gap: 6px;
  height: 26px; padding: 0 10px;
  background: none; border: 0; cursor: pointer;
  color: var(--rail-fg-dim);
  font: 700 10.5px/1 var(--rail-font);
  letter-spacing: 1.4px; text-transform: uppercase;
  width: 100%; text-align: left;
}
#app-rail .rail-group-head:hover{ color: var(--rail-fg); }
#app-rail .rail-group-head .rg-caret{
  flex: 0 0 auto; font-size: 9px;
  transition: transform .2s ease; transform: rotate(90deg);
}
#app-rail .rail-group.collapsed .rg-caret{ transform: rotate(0deg); }
#app-rail .rail-group-head .rg-label{ flex: 1 1 auto; white-space: nowrap; }
body.rail-expanded #app-rail .rail-group-head{ display: flex; }

/* 收起态：分组标题隐藏，项目始终显示（仅 emoji） */
#app-rail .rail-group-items{ display: flex; flex-direction: column; gap: 2px; }
body.rail-expanded #app-rail .rail-group.collapsed .rail-group-items{ display: none; }

/* Item */
#app-rail .rail-item{
  position: relative;
  display: flex; align-items: center; gap: 12px;
  height: 42px; padding: 0 11px;
  border-radius: 10px;
  color: var(--rail-fg);
  text-decoration: none; cursor: pointer;
  transition: background .16s ease, color .16s ease;
  overflow: hidden;
}
#app-rail .rail-item:hover{ background: var(--rail-hover); color: #fff; }
#app-rail .rail-item:focus-visible{ outline: 2px solid var(--rail-active); outline-offset: 2px; }

/* emoji icon（常驻） */
#app-rail .rail-emoji{
  flex: 0 0 auto; width: 24px; height: 24px;
  display: grid; place-items: center;
  font-size: 17px; line-height: 1;
  transition: transform .16s ease;
}
#app-rail .rail-item:hover .rail-emoji{ transform: scale(1.12); }

/* text column（展开态显示） */
#app-rail .rail-text{
  display: none;
  flex-direction: column; min-width: 0; line-height: 1.18;
}
body.rail-expanded #app-rail .rail-text{ display: flex; }
#app-rail .rail-label{ font-size: 13.5px; font-weight: 600; color: #f1f2fb; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
#app-rail .rail-hint{
  font-size: 11.5px; color: var(--rail-fg-dim);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  max-height: 0; opacity: 0;
  transition: max-height .22s ease, opacity .2s ease;
}
#app-rail .rail-hint.show{ max-height: 2.4em; opacity: 1; }

/* active state */
#app-rail .rail-item.rail-item--active{
  background: var(--rail-active-soft);
  color: #fff;
}
#app-rail .rail-item.rail-item--active::before{
  content: ""; position: absolute; left: 0; top: 9px; bottom: 9px;
  width: 3px; border-radius: 3px; background: var(--rail-active);
  animation: railActivePulse 2.6s ease-in-out infinite;
}
@keyframes railActivePulse{
  0%,100%{ opacity: .65; box-shadow: 0 0 0 0 rgba(139,123,255,0); }
  50%{ opacity: 1; box-shadow: 0 0 8px 1px rgba(139,123,255,.45); }
}

/* —— 移动端：抽屉 —— */
@media (max-width: 640px){
  body.has-rail{ padding-left: 0; }
  #app-rail{ transform: translateX(-100%); transition: transform .24s cubic-bezier(.4,0,.2,1); }
  body.rail-expanded #app-rail{ transform: translateX(0); }
}