/* ============================================================================
   正方体三视图 · 设计系统
   世界：方格纸 / 制图（三视图本身就是工程制图的产物，学生的方块也落在格子上）
   策略：Restrained —— 中性纸底 + 一个主色，朱红只用于"当前/刚刚变化"的注意力
   ========================================================================= */

:root {
  --topbar-h: 58px;   /* 顶栏高度：大屏媒体查询里会改成 64px，工作区以此计算可用高度 */

  /* 纸与墨 */
  --paper: #f2f5f9;
  --panel: #ffffff;
  --panel-alt: #eaeff6;
  --ink: #131c26;
  --ink-2: #4c5c70;
  --ink-3: #5c6b7d;
  --line: #d2dbe6;
  --line-strong: #b6c4d4;

  /* 方格纸 */
  --grid: #cfdcec;
  --grid-strong: #b9cbe2;

  /* 主色：制图蓝 */
  --blue: #1b4d8f;
  --blue-mid: #3f7cc4;
  --blue-soft: #e8eff9;
  --blue-line: #9fbde3;

  /* 注意力：朱 */
  --accent: #c2402b;
  --accent-soft: #fbece9;

  --ok: #1c7a52;
  --ok-soft: #e7f4ee;
  --danger: #c2402b;

  --r-sm: 3px;
  --r-md: 5px;
  --r-lg: 8px;

  --shadow-1: 0 1px 2px rgba(19, 28, 38, .07), 0 2px 6px rgba(19, 28, 38, .05);
  --shadow-2: 0 2px 4px rgba(19, 28, 38, .08), 0 10px 24px rgba(19, 28, 38, .09);

  --ui: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --data: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  --tap: 44px;
}

* { box-sizing: border-box; }

/* 组件里大量使用 display，[hidden] 必须能压过它们 */
[hidden] { display: none !important; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: var(--ui);
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  font-size: 15px;
  line-height: 1.5;
}

h1, h2, h3 { margin: 0; font-weight: 650; letter-spacing: -.01em; }

button { font: inherit; color: inherit; }

:focus-visible {
  outline: 2px solid var(--blue-mid);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

/* ---------------------------------------------------------------- 顶栏 */

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  height: var(--topbar-h);
  padding: 0 18px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  position: relative;
  z-index: 5;
}

.status, .btn, .group-chip, .brand { white-space: nowrap; }

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 680;
  font-size: 16px;
  letter-spacing: -.015em;
  white-space: nowrap;
}

.brand svg { display: block; }

.brand small {
  font-weight: 500;
  color: var(--ink-3);
  font-size: 12.5px;
  padding-left: 9px;
  margin-left: 3px;
  border-left: 1px solid var(--line);
}

.topbar .spacer { flex: 1; }

/* ---------------------------------------------------------------- 控件 */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 38px;
  padding: 0 13px;
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-md);
  font-size: 14px;
  font-weight: 550;
  cursor: pointer;
  transition: background-color .16s ease-out, border-color .16s ease-out,
              color .16s ease-out, transform .12s ease-out;
}

.btn:hover:not(:disabled) { background: var(--panel-alt); border-color: var(--ink-3); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.btn-primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
.btn-primary:hover:not(:disabled) { background: #16406f; border-color: #16406f; }

.btn-quiet { border-color: transparent; background: transparent; }
.btn-quiet:hover:not(:disabled) { background: var(--panel-alt); border-color: transparent; }

/* 开关型按钮的激活态：橡皮擦开着要一眼看得出来 */
.btn[aria-pressed="true"] {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
.btn[aria-pressed="true"]:hover { background: #16406f; border-color: #16406f; }

.btn-danger { color: var(--danger); }
.btn-danger:hover:not(:disabled) { background: var(--accent-soft); border-color: var(--accent); }

.btn-block { width: 100%; }

.group-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 38px;
  padding: 0 14px;
  background: var(--blue-soft);
  border: 1px solid var(--blue-line);
  border-radius: var(--r-md);
  font-weight: 620;
  color: var(--blue);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  color: var(--ink-2);
  font-variant-numeric: tabular-nums;
}

.status .dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--ink-3);
  flex: none;
}
.status[data-state="saved"] .dot { background: var(--ok); }
.status[data-state="saving"] .dot { background: var(--blue-mid); }
.status[data-state="error"] .dot { background: var(--danger); }
.status[data-state="offline"] .dot { background: var(--danger); }

/* ---------------------------------------------------------------- 选组 */

.gate {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  grid-template-rows: 1fr auto;
  padding: 40px 24px 28px;
  overflow: auto;
  background: var(--paper);
}

.gate[hidden] { display: none; }

/* 已经认领过组：首页收起，工作区展开（首屏由 <head> 里的内联脚本提前加类，避免闪一下） */
.app { display: none; }
html.has-group .app { display: block; }
html.has-group .gate { display: none; }

.gate-inner {
  width: min(760px, 100%);
  margin: 0 auto;
  align-self: center;
}

.gate h1 {
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1.15;
  margin-bottom: 10px;
}

.gate p.lede {
  color: var(--ink-2);
  font-size: 16px;
  margin: 0 0 28px;
  max-width: 52ch;
}

.gate-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.gate-grid button {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 104px;
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-1);
  cursor: pointer;
  transition: transform .16s cubic-bezier(.2,.7,.3,1), border-color .16s ease-out,
              box-shadow .16s ease-out;
}

.gate-grid button:hover {
  transform: translateY(-3px);
  border-color: var(--blue-mid);
  box-shadow: var(--shadow-2);
}

.gate-grid .n {
  font-family: var(--data);
  font-size: 34px;
  font-weight: 600;
  line-height: 1;
  color: var(--ink);
}

.gate-grid .t { font-size: 13.5px; color: var(--ink-2); }

.gate-grid .taken {
  position: absolute;
  top: 8px; right: 8px;
  font-size: 11.5px;
  color: var(--blue);
  background: var(--blue-soft);
  border-radius: 999px;
  padding: 2px 8px;
}

.gate-note {
  margin: 20px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-2);
}

.gate-foot {
  width: min(760px, 100%);
  margin: 0 auto;
  padding-top: 18px;
  color: var(--ink-3);
  font-size: 12.5px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 教师端入口：放在首页角落，学生平时点不到；进了工作区就没有这个链接 */
.gate-teacher {
  margin-left: auto;
  padding: 8px 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--r-md);
  background: var(--panel);
  color: var(--ink-2);
  font-weight: 560;
  text-decoration: none;
  transition: background-color .16s ease-out, border-color .16s ease-out, color .16s ease-out;
}

.gate-teacher:hover {
  background: var(--blue-soft);
  border-color: var(--blue-mid);
  color: var(--blue);
}

@media (pointer: coarse) {
  .gate-teacher { min-height: 48px; display: inline-flex; align-items: center; padding: 0 18px; }
}

/* ---------------------------------------------------------------- 布局 */

.workspace {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr) 392px;
  gap: 14px;
  padding: 14px;
  height: calc(100vh - var(--topbar-h));
  min-height: 0;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.panel-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  font-size: 13px;
  font-weight: 620;
  color: var(--ink-2);
  letter-spacing: .01em;
}

.panel-body { padding: 12px; overflow: auto; }

/* 工具栏：只有三个按钮，少了就是少了 */

.tool-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px;
}

.tool-tip {
  margin: 0;
  padding: 0 12px 12px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--ink-2);
}


/* ---------------------------------------------------------------- 3D 舞台 */

.stage { position: relative; overflow: hidden; }

.stage canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
  cursor: crosshair;
}

.stage[data-placing="true"] canvas { cursor: copy; }

.stage-hint {
  position: absolute;
  left: 12px;
  bottom: 12px;
  right: 12px;
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  pointer-events: none;
}

.chip {
  background: rgba(255, 255, 255, .93);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 5px 11px;
  font-size: 12.5px;
  color: var(--ink-2);
  box-shadow: var(--shadow-1);
  backdrop-filter: blur(3px);
}

.chip.strong { color: var(--ink); font-weight: 560; }

.stage-stat {
  position: absolute;
  top: 12px;
  left: 12px;
  display: flex;
  gap: 8px;
  align-items: center;
  pointer-events: none;
}

/* 三视图：点一下按钮，三个方向同时显示 */

.view-head { padding: 12px 12px 0; }

.view-placeholder {
  margin: 12px;
  padding: 18px 16px;
  background: var(--panel-alt);
  border-radius: var(--r-md);
  color: var(--ink-2);
  font-size: 13px;
  line-height: 1.5;
}

.view-placeholder[hidden] { display: none; }
.view-placeholder strong { display: block; color: var(--ink); font-size: 14px; margin-bottom: 4px; }
.view-placeholder p { margin: 0; }

.views-grid {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.view-item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 8px 10px 4px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.view-item-title {
  font-size: 13.5px;
  font-weight: 620;
  color: var(--ink);
}

.view-item-canvas {
  display: grid;
  place-items: center;
  overflow: hidden;
}

.view-item-canvas canvas { display: block; }

.view-item-empty {
  font-size: 13px;
  color: var(--ink-3);
}

.view-item-size {
  margin: 0;
  font-family: var(--data);
  font-size: 12.5px;
  color: var(--ink-2);
  text-align: right;
}

.view-foot {
  margin: 0;
  padding: 0 14px 12px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--ink-2);
}


/* ---------------------------------------------------------------- 教师端 */

.teacher-board {
  padding: 14px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-auto-rows: minmax(0, 1fr);
  gap: 12px;
  height: calc(100vh - var(--topbar-h));
  min-height: 0;
}

.group-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
  transition: background-color .22s ease-out;
}

.group-card[data-updated="true"] { background: var(--blue-soft); }
.group-card[data-empty="true"] { border-style: dashed; }

.group-card header {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 11px 13px;
  border-bottom: 1px solid var(--line);
}

.group-card .name { font-weight: 650; font-size: 15px; }
.group-card .count { font-family: var(--data); font-size: 13px; color: var(--blue); }
.group-card .when {
  margin-left: auto;
  font-family: var(--data);
  font-size: 12px;
  color: var(--ink-3);
}

.group-card .card-stage { flex: 1; min-height: 0; position: relative; }
.group-card canvas { display: block; width: 100%; height: 100%; touch-action: none; }

.group-card .card-empty {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 16px;
  color: var(--ink-3);
  font-size: 13.5px;
  pointer-events: none;
}

.group-card .card-empty span { max-width: 22ch; }

/* ---------------------------------------------------------------- 小屏 */

@media (max-width: 1180px) {
  .workspace { grid-template-columns: 148px minmax(0, 1fr) 330px; }
}

@media (max-width: 980px) {
  .workspace {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: auto minmax(280px, 42vh) auto;
    height: auto;
    min-height: calc(100vh - var(--topbar-h));
  }
  .tool-list { flex-direction: row; flex-wrap: wrap; gap: 8px; }
  .tool-list .btn { flex: 1; min-width: 92px; }
  .tool-tip { padding: 0 12px 12px; }
  .views-grid { overflow: visible; }
  .teacher-board { grid-template-columns: repeat(2, minmax(0, 1fr)); height: auto; grid-auto-rows: minmax(240px, 34vh); }
  .gate-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .teacher-board { grid-template-columns: minmax(0, 1fr); }
  .brand small { display: none; }
  .topbar { height: auto; padding: 9px 12px; row-gap: 8px; gap: 10px; }
  .brand { flex: 1 1 100%; font-size: 15px; }
  .brand svg { width: 19px; height: 19px; }
  .workspace { padding: 10px; gap: 10px; }
  .view-item-canvas { min-height: 140px; }
  .gate-grid { grid-template-columns: repeat(2, 1fr); }
  .gate-grid button { min-height: 88px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}

/* ============================================================================
   视角球（平板没有右键，靠它转视角）
   ========================================================================= */

.orbit-pad {
  position: absolute;
  right: 14px;
  bottom: 14px;
  width: 92px;
  height: 92px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .94);
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow-1);
  color: var(--blue);
  cursor: grab;
  touch-action: none;
  user-select: none;
  z-index: 3;
  transition: background-color .16s ease-out, border-color .16s ease-out, transform .12s ease-out;
}

.orbit-pad:hover { background: #fff; border-color: var(--blue-mid); }
.orbit-pad:active,
.orbit-pad[data-active="true"] {
  cursor: grabbing;
  transform: scale(.97);
  background: var(--blue-soft);
  border-color: var(--blue);
}

.orbit-pad svg { width: 40px; height: 40px; display: block; }

.orbit-pad span {
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--ink-2);
}

/* ============================================================================
   教师端：点击卡片放大演示（大屏讲课）
   ========================================================================= */

.group-card { cursor: pointer; }
.group-card:hover { border-color: var(--blue-mid); box-shadow: var(--shadow-1); }
.group-card:focus-within { outline: 2px solid var(--blue-mid); outline-offset: 2px; }

.card-open {
  flex: none;
  min-height: 34px;
  padding: 0 12px;
  margin-left: 10px;
  border-radius: var(--r-md);
  border: 1px solid var(--blue-line);
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 13px;
  font-weight: 620;
  cursor: pointer;
  transition: background-color .16s ease-out, border-color .16s ease-out, color .16s ease-out;
}

.card-open:hover { background: var(--blue); border-color: var(--blue); color: #fff; }

@media (pointer: coarse) {
  .card-open { min-height: 46px; padding: 0 18px; font-size: 15px; }
}

body.is-focusing { overflow: hidden; }

.focus-layer {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: var(--paper);
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
}

.focus-layer[hidden] { display: none !important; }

.focus-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: 12px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.focus-title { display: flex; align-items: baseline; gap: 12px; }
.focus-title strong { font-size: clamp(20px, 2.2vw, 30px); }
.focus-meta { font-family: var(--data); font-size: clamp(13px, 1.1vw, 17px); color: var(--ink-2); }
.focus-actions { margin-left: auto; display: flex; align-items: center; gap: 14px; }
.focus-hint { font-size: 12.5px; color: var(--ink-3); }

.focus-body {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(320px, 1fr);
  gap: 14px;
  padding: 14px;
  min-height: 0;
}

.focus-stage {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  min-height: 0;
}

.focus-stage canvas { display: block; width: 100%; height: 100%; touch-action: none; }

.orbit-pad--large { width: 116px; height: 116px; right: 18px; bottom: 18px; }
.orbit-pad--large svg { width: 50px; height: 50px; }
.orbit-pad--large span { font-size: 12.5px; }

.focus-views {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 0;
  overflow-y: auto;
}

/* ============================================================================
   平板 / 触屏：手指比鼠标粗，所有可点目标放大
   ========================================================================= */

@media (pointer: coarse) {
  .btn { min-height: 50px; font-size: 15.5px; }
  .tool-list .btn { min-height: 56px; font-size: 16.5px; }
  .orbit-pad { width: 104px; height: 104px; }
  .orbit-pad svg { width: 46px; height: 46px; }
  .orbit-pad span { font-size: 12.5px; }
  .chip { font-size: 13px; padding: 6px 12px; }
}

/* 平板横屏（1024~1366）：三栏收窄一点，舞台优先 */
@media (max-width: 1366px) and (min-width: 981px) {
  .workspace { grid-template-columns: 168px minmax(0, 1fr) 344px; gap: 12px; padding: 12px; }
  .tool-tip { display: none; }
}

/* 一体机 / 大屏：整体放大，站远也能看清 */
@media (min-width: 1600px) {
  body { font-size: 16px; }
  :root { --topbar-h: 64px; }
  .workspace { grid-template-columns: 210px minmax(0, 1fr) 440px; gap: 16px; padding: 16px; }
  .btn { min-height: 44px; font-size: 15px; }
  .tool-list .btn { min-height: 52px; font-size: 16px; }
  .tool-tip { font-size: 13.5px; }
  .chip { font-size: 13.5px; padding: 6px 12px; }
  .drag-source { min-height: 44px; }
  .gate h1 { font-size: 42px; }
  .gate-grid button { min-height: 120px; }
  .gate-grid .n { font-size: 40px; }
  .group-card .name { font-size: 17px; }
  .group-card .count { font-size: 14.5px; }
  .group-card .when { font-size: 13.5px; }
}

@media (min-width: 2200px) {
  body { font-size: 17px; }
  .workspace { grid-template-columns: 240px minmax(0, 1fr) 520px; }
  .tool-list .btn { min-height: 60px; font-size: 18px; }
  .orbit-pad { width: 116px; height: 116px; }
  .orbit-pad svg { width: 52px; height: 52px; }
}

/* 窄屏（竖屏平板 / 手机）：放大演示改成上下排 */
@media (max-width: 980px) {
  .focus-body { grid-template-columns: minmax(0, 1fr); grid-template-rows: minmax(240px, 44vh) auto; }
  .focus-layer { overflow-y: auto; }
  .focus-bar { position: sticky; top: 0; z-index: 2; }
  .focus-hint { display: none; }
  .orbit-pad { right: 10px; bottom: 10px; }
}

@media (max-width: 640px) {
  /* 小屏上格子本来就小，视角球缩小并半透明，避免挡住右前角 */
  .orbit-pad {
    width: 76px;
    height: 76px;
    right: 8px;
    bottom: 8px;
    background: rgba(255, 255, 255, .9);
  }
  .orbit-pad svg { width: 32px; height: 32px; }
  .orbit-pad span { font-size: 10.5px; }
}