/* ============================================================
   科学实验台 · 浙教版七年级科学虚拟化学实验平台
   设计系统：浅色 / 通透 / 适合平板触屏
   ============================================================ */

:root {
  --bg: #f4f7fa;
  --bg-2: #eaf0f6;
  --card: #ffffff;
  --ink: #1f2937;
  --ink-2: #4b5563;
  --ink-3: #7b8794;
  --line: #e4e9ef;
  --line-2: #d5dde6;

  --brand: #0e7c86;
  --brand-d: #0a5f68;
  --brand-l: #e6f4f5;
  --brand-2: #1d9fbf;

  --flame: #f97316;
  --flame-l: #fff1e3;
  --warn: #f59e0b;
  --warn-l: #fff8e8;
  --danger: #dc2626;
  --danger-l: #fdeced;
  --ok: #16a34a;
  --ok-l: #eaf7ee;
  --purple: #7c3aed;
  --purple-l: #f1ecfe;

  --r-sm: 8px;
  --r: 12px;
  --r-lg: 18px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 6px 20px rgba(16, 24, 40, .06);
  --shadow-lg: 0 10px 40px rgba(16, 24, 40, .14);

  --stage-w: 760px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; font-size: inherit; color: inherit; }

/* ---------- 通用容器 ---------- */
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 20px; }

/* ---------- 顶栏 ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar-in {
  max-width: 1180px;
  margin: 0 auto;
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
  color: var(--ink);
  letter-spacing: .3px;
}
.logo:hover { text-decoration: none; }
.logo-mark {
  width: 32px; height: 32px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  color: #fff;
  display: grid; place-items: center;
  font-size: 17px;
  box-shadow: 0 3px 10px rgba(14, 124, 134, .3);
}
.logo-sub {
  font-size: 12px;
  font-weight: 500;
  color: var(--ink-3);
  border-left: 1px solid var(--line-2);
  padding-left: 10px;
  margin-left: 2px;
}
.topbar-spacer { flex: 1; }
.topbar-link {
  font-size: 13px;
  color: var(--ink-2);
  padding: 6px 11px;
  border-radius: 999px;
  border: 1px solid transparent;
}
.topbar-link:hover { background: var(--bg-2); text-decoration: none; }

/* ---------- 首页 Hero ---------- */
.hero {
  background:
    radial-gradient(900px 340px at 12% -10%, #d7eef0 0%, rgba(215,238,240,0) 60%),
    radial-gradient(700px 300px at 88% 0%, #e3ecff 0%, rgba(227,236,255,0) 62%),
    var(--card);
  border-bottom: 1px solid var(--line);
}
.hero-in {
  max-width: 1180px;
  margin: 0 auto;
  padding: 42px 20px 38px;
  display: flex;
  gap: 36px;
  align-items: center;
  flex-wrap: wrap;
}
.hero-txt { flex: 1 1 380px; min-width: 300px; }
.hero h1 {
  font-size: 30px;
  line-height: 1.32;
  margin: 0 0 12px;
  letter-spacing: -.3px;
}
.hero h1 em {
  font-style: normal;
  color: var(--brand);
}
.hero p {
  margin: 0 0 18px;
  color: var(--ink-2);
  font-size: 15px;
  max-width: 560px;
}
.hero-tips { display: flex; gap: 8px; flex-wrap: wrap; }
.tip {
  font-size: 12.5px;
  background: #fff;
  border: 1px solid var(--line-2);
  color: var(--ink-2);
  padding: 4px 11px;
  border-radius: 999px;
}

/* 进度卡 */
.progress-card {
  flex: 0 0 auto;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  padding: 18px 22px;
  display: flex;
  align-items: center;
  gap: 18px;
}
.ring { position: relative; width: 78px; height: 78px; flex: 0 0 auto; }
.ring svg { transform: rotate(-90deg); }
.ring-txt {
  position: absolute; inset: 0;
  display: grid; place-items: center;
  font-weight: 700; font-size: 17px; color: var(--brand);
}
.ring-txt small { display: block; font-size: 10px; color: var(--ink-3); font-weight: 500; margin-top: -2px; }
.progress-meta { font-size: 13px; color: var(--ink-2); }
.progress-meta b { color: var(--ink); font-size: 15px; }
.progress-meta div + div { margin-top: 3px; }

/* ---------- 视图切换 ---------- */
.viewswitch {
  display: inline-flex;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 3px;
  gap: 2px;
}
.viewswitch button {
  border: 0;
  background: transparent;
  padding: 7px 18px;
  border-radius: 999px;
  font-size: 13.5px;
  color: var(--ink-2);
  cursor: pointer;
  transition: .16s;
}
.viewswitch button.on {
  background: #fff;
  color: var(--brand);
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(16, 24, 40, .1);
}

.section-head {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  margin: 32px 0 14px;
}
.section-head h2 {
  font-size: 19px;
  margin: 0;
  letter-spacing: -.2px;
}
.section-head .desc { font-size: 13px; color: var(--ink-3); }

/* ---------- 章节 ---------- */
.chapter {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  margin-bottom: 14px;
  overflow: hidden;
}
.chapter-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  cursor: pointer;
  user-select: none;
}
.chapter-no {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-l);
  border-radius: 7px;
  padding: 3px 9px;
  flex: 0 0 auto;
}
.chapter-title { font-weight: 600; font-size: 15.5px; flex: 1; }
.chapter-count { font-size: 12.5px; color: var(--ink-3); }
.caret { transition: transform .2s; color: var(--ink-3); font-size: 12px; }
.chapter.collapsed .caret { transform: rotate(-90deg); }
.chapter.collapsed .chapter-body { display: none; }
.chapter-body { padding: 0 18px 16px; }

/* ---------- 实验卡片 ---------- */
.exp-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(268px, 1fr));
  gap: 12px;
  margin-top: 4px;
}
.exp-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 15px 16px 13px;
  cursor: pointer;
  transition: .18s;
  display: flex;
  flex-direction: column;
  gap: 9px;
  position: relative;
  overflow: hidden;
}
.exp-card::before {
  content: "";
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--brand);
  opacity: .8;
}
.exp-card:hover {
  border-color: var(--brand-2);
  box-shadow: 0 6px 20px rgba(14, 124, 134, .14);
  transform: translateY(-2px);
}
.exp-card .row1 { display: flex; align-items: center; gap: 8px; }
.exp-card h3 { font-size: 16px; margin: 0; flex: 1; letter-spacing: -.2px; }
.exp-card .desc { font-size: 13px; color: var(--ink-2); margin: 0; }
.exp-card .foot { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-top: 2px; }

.badge {
  font-size: 11.5px;
  padding: 2px 8px;
  border-radius: 6px;
  background: var(--bg-2);
  color: var(--ink-2);
  white-space: nowrap;
}
.badge.hot { background: var(--danger-l); color: var(--danger); font-weight: 600; }
.badge.often { background: var(--warn-l); color: #b45309; font-weight: 600; }
.badge.know { background: var(--brand-l); color: var(--brand-d); }
.badge.time { background: #eef2f7; color: var(--ink-3); }
.badge.done { background: var(--ok-l); color: var(--ok); font-weight: 600; }
.badge.tag { background: #f1f5f9; color: var(--ink-3); }

.done-check {
  position: absolute;
  right: 12px; bottom: 10px;
  font-size: 12px;
  color: var(--ok);
  font-weight: 600;
}

/* 规划中 */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 10px;
}
.roadmap-item {
  border: 1px dashed var(--line-2);
  border-radius: var(--r);
  padding: 12px 14px;
  background: rgba(255, 255, 255, .6);
}
.roadmap-item .t { font-weight: 600; font-size: 14px; }
.roadmap-item .s { font-size: 12px; color: var(--ink-3); margin-top: 2px; }

/* ---------- 页脚 ---------- */
.footer {
  margin-top: 48px;
  border-top: 1px solid var(--line);
  background: #fff;
  padding: 26px 20px 34px;
  color: var(--ink-3);
  font-size: 13px;
}
.footer-in { max-width: 1180px; margin: 0 auto; }
.footer b { color: var(--ink-2); }

/* ============================================================
   实验页
   ============================================================ */
.exp-top {
  background: #fff;
  border-bottom: 1px solid var(--line);
}
.exp-top-in {
  max-width: 1360px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.back-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13.5px; color: var(--ink-2);
  border: 1px solid var(--line-2);
  border-radius: 999px;
  padding: 5px 13px;
  background: #fff;
}
.back-link:hover { background: var(--bg-2); text-decoration: none; }
.exp-title { font-size: 18px; font-weight: 700; margin: 0; }
.exp-meta { display: flex; gap: 7px; flex-wrap: wrap; align-items: center; }

.layout {
  max-width: 1360px;
  margin: 0 auto;
  padding: 18px 20px 40px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 372px;
  gap: 18px;
  align-items: start;
}

/* 模拟区 */
.stage-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.stage-head {
  padding: 11px 16px;
  border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 10px;
  font-size: 13px; color: var(--ink-3);
}
.stage-head .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--ok); }
.stage-canvas-wrap { padding: 14px 16px 0; }
canvas.sim {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--r);
  background: linear-gradient(180deg, #fbfdfe 0%, #f2f7fa 100%);
  touch-action: none;
}
.stage-ctrl { padding: 14px 16px 16px; }

/* 控件 */
.ctrl-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 22px;
  align-items: flex-end;
}
.ctrl {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 150px;
}
.ctrl-label {
  font-size: 12.5px;
  color: var(--ink-3);
  display: flex; align-items: center; gap: 6px;
}
.ctrl-label b { color: var(--ink); font-weight: 600; font-size: 13px; }
.slider-line { display: flex; align-items: center; gap: 10px; }
input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  width: 190px;
  height: 4px;
  border-radius: 999px;
  background: var(--line-2);
  outline: none;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--brand);
  box-shadow: 0 2px 6px rgba(16, 24, 40, .18);
  cursor: pointer;
}
input[type=range]::-moz-range-thumb {
  width: 16px; height: 16px; border-radius: 50%;
  background: #fff; border: 3px solid var(--brand); cursor: pointer;
}
.val {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--brand);
  min-width: 62px;
  font-size: 14px;
}

.seg {
  display: inline-flex;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 3px;
  gap: 2px;
}
.seg button {
  border: 0; background: transparent;
  padding: 5px 12px; border-radius: 7px;
  font-size: 13px; color: var(--ink-2); cursor: pointer; transition: .15s;
}
.seg button.on { background: #fff; color: var(--brand); font-weight: 600; box-shadow: 0 1px 3px rgba(16, 24, 40, .1); }

.btn {
  border: 1px solid var(--line-2);
  background: #fff;
  border-radius: 9px;
  padding: 8px 16px;
  font-size: 13.5px;
  cursor: pointer;
  transition: .15s;
  display: inline-flex; align-items: center; gap: 6px;
  color: var(--ink);
}
.btn:hover { background: var(--bg-2); }
.btn.primary {
  background: var(--brand);
  border-color: var(--brand);
  color: #fff;
  font-weight: 600;
}
.btn.primary:hover { background: var(--brand-d); }
.btn.warn { background: var(--flame); border-color: var(--flame); color: #fff; font-weight: 600; }
.btn.warn:hover { filter: brightness(.94); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-sm { padding: 5px 11px; font-size: 12.5px; }

.switch {
  display: inline-flex; align-items: center; gap: 9px;
  cursor: pointer; user-select: none;
}
.switch input { display: none; }
.switch .track {
  width: 44px; height: 24px; border-radius: 999px;
  background: var(--line-2);
  position: relative; transition: .18s;
  flex: 0 0 auto;
}
.switch .track::after {
  content: ""; position: absolute;
  top: 3px; left: 3px;
  width: 18px; height: 18px; border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, .2);
  transition: .18s;
}
.switch input:checked + .track { background: var(--brand); }
.switch input:checked + .track::after { transform: translateX(20px); }
.switch .txt { font-size: 13.5px; }
.switch .txt b { color: var(--brand); }

/* 试剂/样本筹码 */
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  border: 1px solid var(--line-2);
  background: #fff;
  border-radius: 999px;
  padding: 6px 13px;
  font-size: 13px;
  cursor: grab;
  display: inline-flex; align-items: center; gap: 7px;
  transition: .15s;
  touch-action: none;
}
.chip:hover { border-color: var(--brand-2); }
.chip.sel { border-color: var(--brand); background: var(--brand-l); color: var(--brand-d); font-weight: 600; }
.chip .sw { width: 12px; height: 12px; border-radius: 50%; flex: 0 0 auto; border: 1px solid rgba(0,0,0,.12); }
.chip small { color: var(--ink-3); font-size: 11.5px; }
.chip.sel small { color: var(--brand); }

.drag-ghost {
  position: fixed;
  z-index: 9999;
  pointer-events: none;
  transform: translate(-50%, -50%) scale(1.06);
  opacity: .95;
  box-shadow: var(--shadow-lg);
}

/* 状态条 */
.status-bar {
  margin: 12px 16px 0;
  border-radius: 9px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 9px 13px;
  font-size: 13px;
  color: var(--ink-2);
  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;
  min-height: 40px;
}
.status-bar b { color: var(--ink); }
.status-bar .ok { color: var(--ok); font-weight: 600; }
.status-bar .no { color: var(--danger); font-weight: 600; }
.status-bar .fire { color: var(--flame); font-weight: 700; }

/* ---- 右栏 ---- */
.side {
  position: sticky;
  top: 74px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.tabs {
  display: flex;
  border-bottom: 1px solid var(--line);
  background: #fbfcfd;
}
.tabs button {
  flex: 1;
  border: 0;
  background: transparent;
  padding: 12px 4px;
  font-size: 13.5px;
  color: var(--ink-3);
  cursor: pointer;
  position: relative;
  transition: .15s;
}
.tabs button.on { color: var(--brand); font-weight: 600; }
.tabs button.on::after {
  content: ""; position: absolute; left: 14%; right: 14%; bottom: 0;
  height: 2.5px; background: var(--brand); border-radius: 3px 3px 0 0;
}
.tabs .dot-new {
  display: inline-block; width: 6px; height: 6px; border-radius: 50%;
  background: var(--flame); margin-left: 4px; vertical-align: 2px;
}
.panel { padding: 14px 16px 18px; max-height: calc(100vh - 190px); overflow-y: auto; }
.panel::-webkit-scrollbar { width: 8px; }
.panel::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 8px; }

.steps { list-style: none; margin: 0; padding: 0; counter-reset: s; }
.steps li {
  position: relative;
  padding: 0 0 14px 30px;
  font-size: 13.5px;
  color: var(--ink-2);
  counter-increment: s;
}
.steps li::before {
  content: counter(s);
  position: absolute; left: 0; top: 1px;
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--brand-l); color: var(--brand-d);
  font-size: 11.5px; font-weight: 700;
  display: grid; place-items: center;
}
.steps li::after {
  content: ""; position: absolute; left: 9.5px; top: 24px; bottom: 2px;
  width: 1px; background: var(--line);
}
.steps li:last-child { padding-bottom: 0; }
.steps li:last-child::after { display: none; }
.steps li.done { color: var(--ok); }
.steps li.done::before { background: var(--ok); color: #fff; content: "✓"; }
.steps li b { color: var(--ink); }

/* 现象 */
.log-list { list-style: none; margin: 0; padding: 0; }
.log-list li {
  font-size: 13.5px;
  padding: 9px 11px;
  border-radius: 9px;
  background: var(--bg-2);
  margin-bottom: 8px;
  color: var(--ink-2);
  animation: fade .25s ease;
}
.log-list li.hi { background: var(--flame-l); color: #9a3412; font-weight: 600; }
.log-list li.good { background: var(--ok-l); color: #15803d; }
.empty { color: var(--ink-3); font-size: 13px; text-align: center; padding: 26px 10px; }

@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

/* 知识卡 */
.kcard {
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 13px 14px;
  margin-bottom: 11px;
  background: #fff;
}
.kcard h4 {
  margin: 0 0 7px;
  font-size: 14.5px;
  display: flex; align-items: center; gap: 7px;
}
.kcard h4 .ic { font-size: 15px; }
.kcard p { margin: 0 0 7px; font-size: 13.5px; color: var(--ink-2); }
.kcard p:last-child { margin-bottom: 0; }
.kcard .formula {
  display: block;
  background: var(--bg-2);
  border-radius: 8px;
  padding: 8px 11px;
  font-size: 13px;
  color: var(--ink);
  margin: 7px 0;
  font-variant-numeric: tabular-nums;
}
.kcard.conclusion {
  border-color: var(--brand-2);
  background: linear-gradient(180deg, var(--brand-l) 0%, #fff 70%);
  box-shadow: 0 3px 14px rgba(14, 124, 134, .12);
}
.kcard.locked { opacity: .55; filter: grayscale(.4); }
.lock-note {
  font-size: 12.5px; color: var(--ink-3);
  background: var(--bg-2); border-radius: 8px;
  padding: 8px 11px; margin-top: 8px;
}

/* 中考真题 */
.q-card {
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 13px 14px;
  margin-bottom: 12px;
}
.q-title { font-size: 14px; font-weight: 600; margin: 0 0 10px; line-height: 1.6; }
.q-title .no { color: var(--brand); margin-right: 6px; }
.opts { display: flex; flex-direction: column; gap: 7px; }
.opt {
  border: 1px solid var(--line-2);
  border-radius: 9px;
  padding: 8px 12px;
  font-size: 13.5px;
  cursor: pointer;
  transition: .15s;
  background: #fff;
  text-align: left;
  display: block; width: 100%;
}
.opt:hover:not(:disabled) { border-color: var(--brand-2); background: #fafdfe; }
.opt:disabled { cursor: default; }
.opt.right { border-color: var(--ok); background: var(--ok-l); color: #15803d; font-weight: 600; }
.opt.wrong { border-color: var(--danger); background: var(--danger-l); color: var(--danger); }
.expl {
  margin-top: 10px;
  font-size: 13px;
  background: var(--bg-2);
  border-radius: 8px;
  padding: 9px 11px;
  color: var(--ink-2);
}
.expl b { color: var(--ink); }

.finish {
  margin-top: 14px;
  border-top: 1px dashed var(--line-2);
  padding-top: 14px;
}
.finish .btn { width: 100%; justify-content: center; }
.note-mini { font-size: 12px; color: var(--ink-3); margin-top: 8px; text-align: center; }

/* 安全提示 */
.safety-list { list-style: none; margin: 0 0 10px; padding: 0; }
.safety-list li {
  font-size: 13.5px; color: var(--ink-2);
  padding: 7px 0 7px 22px; position: relative;
}
.safety-list li::before {
  content: "⚠"; position: absolute; left: 0; top: 7px; font-size: 12px;
}

/* ---------- 弹窗 ---------- */
.mask {
  position: fixed; inset: 0;
  background: rgba(17, 24, 39, .5);
  backdrop-filter: blur(3px);
  display: grid; place-items: center;
  z-index: 200;
  padding: 20px;
  animation: fade .2s ease;
}
.modal {
  background: #fff;
  border-radius: var(--r-lg);
  max-width: 470px;
  width: 100%;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: pop .22s cubic-bezier(.2, .9, .3, 1.2);
  max-height: 88vh;
  display: flex;
  flex-direction: column;
}
@keyframes pop { from { transform: scale(.94); opacity: 0; } to { transform: none; opacity: 1; } }
.modal-head {
  padding: 17px 20px 13px;
  border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 10px;
}
.modal-head .ic {
  width: 30px; height: 30px; border-radius: 9px;
  background: var(--warn-l); color: var(--warn);
  display: grid; place-items: center; font-size: 16px;
  flex: 0 0 auto;
}
.modal-head h3 { margin: 0; font-size: 16.5px; }
.modal-body { padding: 6px 20px 16px; overflow-y: auto; }
.modal-foot {
  padding: 13px 20px 17px;
  border-top: 1px solid var(--line);
  display: flex; gap: 10px;
}
.modal-foot .btn { flex: 1; justify-content: center; }
.check-row {
  display: flex; align-items: center; gap: 9px;
  font-size: 13.5px; color: var(--ink-2);
  margin-top: 12px; cursor: pointer;
}
.check-row input { width: 17px; height: 17px; accent-color: var(--brand); }

/* ---------- toast ---------- */
.toast-wrap {
  position: fixed;
  left: 50%; bottom: 34px;
  transform: translateX(-50%);
  z-index: 300;
  display: flex; flex-direction: column; gap: 8px; align-items: center;
  pointer-events: none;
}
.toast {
  background: rgba(24, 32, 44, .93);
  color: #fff;
  font-size: 13.5px;
  padding: 9px 18px;
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  animation: toastIn .22s ease;
}
@keyframes toastIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

/* ---------- 分类筐（物质变化实验） ---------- */
.bin-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 14px;
}
.bin {
  border: 2px dashed var(--line-2);
  border-radius: var(--r);
  min-height: 132px;
  padding: 10px;
  display: flex; flex-wrap: wrap; gap: 7px; align-content: flex-start;
  transition: .15s;
  background: #fcfdfe;
}
.bin .bin-title {
  width: 100%;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-3);
  margin-bottom: 2px;
}
.bin.over { border-color: var(--brand); background: var(--brand-l); }
.bin.phys.over { border-color: var(--brand-2); background: #eaf6fb; }
.bin.chem.over { border-color: var(--purple); background: var(--purple-l); }
.mini {
  font-size: 12.5px;
  padding: 4px 10px;
  border-radius: 7px;
  background: #fff;
  border: 1px solid var(--line-2);
  cursor: grab;
  touch-action: none;
}
.mini.phys { border-color: #b6e3f0; background: #f0fafd; color: #0e6f8a; }
.mini.chem { border-color: #ddd0fb; background: #f7f4fe; color: #6d28d9; }
.mini.wrong { animation: shake .35s; border-color: var(--danger); background: var(--danger-l); color: var(--danger); }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* 金属性质实验的信息表 */
.mini-table { width: 100%; border-collapse: collapse; font-size: 13px; margin-top: 8px; }
.mini-table th, .mini-table td {
  border: 1px solid var(--line);
  padding: 6px 9px;
  text-align: left;
}
.mini-table th { background: var(--bg-2); font-weight: 600; font-size: 12.5px; }

.readout {
  font-size: 13px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 10px 12px;
  margin-top: 12px;
  color: var(--ink-2);
  min-height: 44px;
}
.readout b { color: var(--ink); }

.hint-line { font-size: 12.5px; color: var(--ink-3); margin-top: 10px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .layout { grid-template-columns: 1fr; }
  .side { position: static; }
  .panel { max-height: none; }
}
@media (max-width: 720px) {
  .hero-in { padding: 30px 18px 26px; }
  .hero h1 { font-size: 23px; }
  .progress-card { width: 100%; }
  .wrap { padding: 0 16px; }
  .exp-top-in { padding: 12px 16px; }
  .layout { padding: 14px 16px 32px; }
  .stage-canvas-wrap { padding: 10px 10px 0; }
  .side { border-radius: var(--r); }
  .tabs button { font-size: 12.5px; padding: 11px 2px; }
  .bin-wrap { grid-template-columns: 1fr; }
  input[type=range] { width: 150px; }
  .logo-sub { display: none; }
}