/* 可触摸插图的样式。颜色全部来自站点同步进 iframe 的变量（--paper、--pencil、--marker …），
   下面的值只是独立打开时的回退。深色模式和配色由站点写到 <html data-theme data-palette>。
   画风照首页 Hero 的机械臂：4px 铅笔线、6px 连杆、白心关节、marker 色夹爪和虚线十字靶。 */
:root {
  --paper: #f6f7f4;
  --paper-2: #ffffff;
  --erased: #e0e3e0;
  --pencil: #1f2433;
  --pencil-60: rgba(31, 36, 51, 0.6);
  --pencil-45: rgba(31, 36, 51, 0.45);
  --pencil-25: rgba(31, 36, 51, 0.25);
  --pencil-12: rgba(31, 36, 51, 0.12);
  --marker: #c4562f;
  --pen: #3b4f9e;
  --postit: #e6ebfa;
  --postit-2: #dcefe4;
  --postit-3: #f8e5dc;
  --tape: rgba(255, 236, 150, 0.7);
  --font-body: 'LXGW WenKai Screen', 'KaiTi', 'STKaiti', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, 'Liberation Mono', 'LXGW WenKai Screen', monospace;
  --radius-wobble-sm: 180px 15px 180px 15px / 15px 180px 15px 180px;
  --radius-pill: 999px 18px 999px 18px / 18px 999px 18px 999px;
  --shadow-soft: 3px 3px 0 0 rgba(31, 36, 51, 0.1);
  --shadow-hand-sm: 2px 2px 0 0 var(--pencil);
  color-scheme: light;
}
html[data-theme='dark'] {
  color-scheme: dark;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  background: transparent;
}
body {
  font-family: var(--font-body);
  color: var(--pencil);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
button,
input {
  font: inherit;
  color: inherit;
}
:focus-visible {
  outline: 2px dashed var(--marker);
  outline-offset: 2px;
}

/* ---------- 一张图：点阵纸上左边画、右边一张小卡片，底下一句「你看到的是什么」 ---------- */
.fig {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 11.5rem;
  grid-template-rows: auto 1fr auto;
  grid-template-areas: 'stage head' 'stage body' 'note note';
  gap: 0.45rem 0.9rem;
  padding: 0.6rem 0.8rem 0.65rem;
  background-color: var(--paper);
  background-image: radial-gradient(var(--erased) 1px, transparent 1px);
  background-size: 20px 20px;
}
.fig-stage {
  grid-area: stage;
  align-self: center;
  min-width: 0;
}
.fig-head,
.fig-body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.45rem;
  min-width: 0;
}
.fig-head {
  grid-area: head;
  padding-top: 0.2rem;
}
.fig-body {
  grid-area: body;
}
.fig-tag {
  padding: 0 0.6rem;
  border: 2px solid var(--pencil);
  border-radius: var(--radius-wobble-sm);
  background: var(--postit);
  font-size: 0.82rem;
  transform: rotate(-2deg);
}
.fig-hint {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.5;
  color: var(--pencil-60);
}
/* 读数：一张小白卡，数字用等宽，拖动时不左右跳 */
.fig-readout {
  width: 100%;
  padding: 0.35rem 0.6rem;
  background: var(--paper-2);
  border: 2px solid var(--pencil);
  border-radius: 12px 18px 14px 16px / 16px 14px 18px 12px;
  box-shadow: var(--shadow-soft);
  font-size: 0.86rem;
  line-height: 1.55;
}
.fig-readout:empty {
  display: none;
}
.fig-readout .row {
  display: flex;
  justify-content: space-between;
  gap: 0.6rem;
}
.fig-readout .k {
  color: var(--pencil-60);
}
.fig-readout .v {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.fig-readout .row.is-big .v {
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 700;
}
.fig-readout .row.is-hot .v {
  color: var(--marker);
  font-weight: 700;
}
/* 底下那句话：留够两行，文字长短变化时 iframe 高度不跳 */
.fig-note {
  grid-area: note;
  margin: 0;
  min-height: 3.2em;
  padding: 0.1rem 0.2rem 0;
  font-size: 0.9rem;
  line-height: 1.6;
}
.fig-note b {
  color: var(--marker);
}

/* ---------- 控件：胶囊按钮、手绘开关、手绘滑块 ---------- */
.fig-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.5rem;
  width: 100%;
}
.fig-controls:empty {
  display: none;
}
.fig-btn {
  padding: 0.05rem 0.75rem;
  font-size: 0.85rem;
  line-height: 1.6;
  background: var(--paper-2);
  border: 2px solid var(--pencil);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-hand-sm);
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.1s ease;
}
.fig-btn:hover {
  background: var(--marker);
  color: #fff;
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0 0 var(--pencil);
}
.fig-btn:active {
  transform: translate(2px, 2px);
  box-shadow: none;
}
.fig-btn:disabled {
  opacity: 0.45;
  cursor: default;
  background: var(--paper-2);
  color: var(--pencil);
  transform: none;
  box-shadow: var(--shadow-hand-sm);
}
.fig-btn.is-quiet {
  border-width: 1.5px;
  box-shadow: none;
}
.fig-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0;
  font-size: 0.86rem;
  background: none;
  border: 0;
  cursor: pointer;
}
.fig-toggle .box {
  position: relative;
  flex: none;
  width: 1.05rem;
  height: 1.05rem;
  background: var(--paper-2);
  border: 2px solid var(--pencil);
  border-radius: 4px 6px 3px 5px;
  box-shadow: 1.5px 1.5px 0 0 var(--pencil);
}
.fig-toggle[aria-pressed='true'] .box {
  background: var(--postit-2);
}
/* 勾：两条边的 L 形转 45°，像随手打的钩 */
.fig-toggle[aria-pressed='true'] .box::after {
  content: '';
  position: absolute;
  left: 0.22rem;
  top: -0.2rem;
  width: 0.4rem;
  height: 0.8rem;
  border: solid var(--marker);
  border-width: 0 3px 3px 0;
  border-radius: 1px 1px 3px 1px;
  transform: rotate(40deg);
}
.fig-toggle:hover .box {
  transform: translate(1px, 1px);
  box-shadow: 0.5px 0.5px 0 0 var(--pencil);
}
.fig-slider {
  display: flex;
  flex: 1 1 9.5rem;
  flex-direction: column;
  gap: 0.05rem;
  min-width: 0;
  font-size: 0.86rem;
}
.fig-slider .head {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
}
.fig-slider .val {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--marker);
}
/* 滑块自己画：铅笔描边的轨道，左边涂上便签色，拇指是一颗歪一点的白纽扣 */
.fig-slider input[type='range'] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 1.5rem;
  margin: 0;
  background: transparent;
  cursor: pointer;
}
.fig-slider input[type='range']::-webkit-slider-runnable-track {
  box-sizing: border-box;
  height: 0.75rem;
  border: 2px solid var(--pencil);
  border-radius: 999px 12px 999px 12px / 12px 999px 12px 999px;
  background: linear-gradient(to right, var(--postit-3) 0 var(--fill, 50%), var(--paper-2) var(--fill, 50%));
}
.fig-slider input[type='range']::-moz-range-track {
  box-sizing: border-box;
  height: 0.75rem;
  border: 2px solid var(--pencil);
  border-radius: 999px 12px 999px 12px / 12px 999px 12px 999px;
  background: linear-gradient(to right, var(--postit-3) 0 var(--fill, 50%), var(--paper-2) var(--fill, 50%));
}
.fig-slider input[type='range']::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  box-sizing: border-box;
  width: 1.15rem;
  height: 1.15rem;
  margin-top: calc((0.75rem - 4px - 1.15rem) / 2);
  background: var(--paper-2);
  border: 2px solid var(--pencil);
  border-radius: 55% 45% 50% 50% / 45% 55% 45% 55%;
  box-shadow: 1.5px 1.5px 0 0 var(--pencil);
}
.fig-slider input[type='range']::-moz-range-thumb {
  box-sizing: border-box;
  width: 1.15rem;
  height: 1.15rem;
  background: var(--paper-2);
  border: 2px solid var(--pencil);
  border-radius: 55% 45% 50% 50% / 45% 55% 45% 55%;
  box-shadow: 1.5px 1.5px 0 0 var(--pencil);
}
.fig-slider input[type='range']:hover::-webkit-slider-thumb {
  background: var(--marker);
}
.fig-slider input[type='range']:hover::-moz-range-thumb {
  background: var(--marker);
}
.fig-slider input[type='range']:focus-visible {
  outline: 2px dashed var(--marker);
  outline-offset: 3px;
}

/* ---------- SVG：和首页机械臂同一支笔 ---------- */
.fig-svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: hidden;
  fill: none;
  stroke: var(--pencil);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-linejoin: round;
  -webkit-user-select: none;
  user-select: none;
}
.fig-svg text {
  fill: var(--pencil-60);
  stroke: none;
  font-family: var(--font-body);
  font-size: 15px;
}
.fig-svg text.is-strong {
  fill: var(--pencil);
  font-weight: 700;
}
.fig-svg text.is-marker {
  fill: var(--marker);
}
.fig-svg text.is-pen {
  fill: var(--pen);
}
.arm-base .joint,
.arm .joint {
  fill: var(--paper-2);
}
.arm .link {
  stroke-width: 6;
}
.arm .tip {
  fill: var(--marker);
}
/* 影子手臂：另一个解、上一步、残影。细虚线，不抢主角 */
.arm.is-ghost {
  stroke: var(--pencil-45);
  stroke-width: 2.5;
  stroke-dasharray: 5 5;
}
.arm.is-ghost .link {
  stroke-width: 3;
}
.arm.is-ghost .joint {
  fill: var(--paper);
  stroke-dasharray: none;
}
.arm.is-ghost .tip {
  fill: var(--pencil-25);
  stroke: none;
}
.arm.is-faint {
  stroke: var(--pencil-25);
  stroke-dasharray: none;
}
.arm.is-faint .joint {
  stroke: var(--pencil-25);
}
.arm.is-dim {
  opacity: 0.45;
}
.target {
  stroke: var(--marker);
  stroke-width: 2.5;
  stroke-dasharray: 4 3;
}
/* 辅助线：指尖轨迹、构造线、角度弧、可达区域 */
.trail {
  stroke: var(--pen);
  stroke-width: 2.5;
  stroke-dasharray: 1 6;
}
.guide {
  stroke: var(--pencil-25);
  stroke-width: 2;
  stroke-dasharray: 4 6;
}
.guide.is-pen {
  stroke: var(--pen);
  opacity: 0.75;
}
.guide.is-marker {
  stroke: var(--marker);
}
.angle {
  stroke: var(--pen);
  stroke-width: 2.5;
}
.angle.is-marker {
  stroke: var(--marker);
}
.zone {
  fill: var(--postit-2);
  fill-rule: evenodd;
  stroke: var(--pencil-25);
  stroke-width: 2;
  stroke-dasharray: 6 5;
}
.zone.is-pen {
  fill: var(--postit);
}
.zone.is-hot {
  fill: var(--postit-3);
}
.ray {
  stroke-width: 2.5;
  stroke-dasharray: 6 5;
}
.ray.is-tip {
  stroke: var(--pen);
}
.ray.is-target {
  stroke: var(--marker);
}
.vec {
  stroke-width: 3;
}
.vec.is-pen {
  stroke: var(--pen);
}
.vec.is-marker {
  stroke: var(--marker);
}
.active-ring {
  stroke: var(--marker);
  stroke-width: 3;
}

/* ---------- 拖动柄：透明的大触摸区 + 一圈虚线提示「这里能拖」 ---------- */
.handle {
  cursor: grab;
  touch-action: none;
  outline: none;
}
.handle.is-dragging {
  cursor: grabbing;
}
.handle .hit {
  fill: transparent;
  stroke: none;
}
.handle .ring {
  stroke: var(--marker);
  stroke-width: 2;
  stroke-dasharray: 3 4;
  opacity: 0.55;
}
.handle:hover .ring,
.handle.is-dragging .ring {
  opacity: 1;
}
.handle:focus-visible .ring {
  opacity: 1;
  stroke-width: 2.5;
  stroke-dasharray: 5 3;
}
/* 靶子自己就是虚线圆，平时不再加一圈；键盘聚焦时才出现 */
.handle.is-target .ring {
  opacity: 0;
}
.handle.is-target:focus-visible .ring {
  opacity: 1;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 窄：卡片落到图下面 ---------- */
@media (max-width: 520px) {
  .fig {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: auto;
    grid-template-areas: 'head' 'stage' 'body' 'note';
    padding: 0.55rem 0.55rem 0.6rem;
  }
  .fig-head {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.2rem 0.6rem;
    padding-top: 0;
  }
  .fig-note {
    min-height: 4.8em;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}