/*
  交互几何题页统一样式（数学说）
  与 internal/templates/interactive_geometry_page_style.css 内容一致；题页中引用：
  <link rel="stylesheet" href="../../../assets/css/interactive-geometry-page.css" />
*/

:root {
  --bg: #f6f0e5;
  --panel: rgba(255, 251, 245, 0.94);
  --ink: #1f2937;
  --muted: #6b7280;
  --line: rgba(120, 53, 15, 0.14);
  --accent: #0f766e;
  --warn: #b45309;
  --focus: #dc2626;
  --paper: rgba(245, 158, 11, 0.16);
  --paper-stroke: #d97706;
  /* 折叠/动区：折叠题用 --fold，平移等题在脚本里可用 --moving（同色链） */
  --fold: rgba(14, 116, 144, 0.18);
  --fold-stroke: #0f766e;
  --moving: var(--fold);
  --moving-stroke: var(--fold-stroke);
  --overlap: rgba(220, 38, 38, 0.18);
  --overlap-stroke: #b91c1c;
  --shadow: 0 18px 54px rgba(120, 53, 15, 0.12);
  /* 少量题图标注备用 */
  --accent-2: #2563eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(circle at 10% 5%, rgba(251, 191, 36, 0.16), transparent 24%),
    radial-gradient(circle at 90% 0%, rgba(14, 116, 144, 0.12), transparent 28%),
    linear-gradient(180deg, #fbf7ef 0%, var(--bg) 100%);
  padding: 16px;
}

.lesson-topbar {
  max-width: 1380px;
  margin: 0 auto 10px;
  padding: 0 4px 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  font-size: 14px;
  color: var(--muted);
}

.lesson-topbar a {
  color: var(--accent);
  font-weight: 800;
  text-decoration: none;
  border-bottom: 1px solid rgba(15, 118, 110, 0.25);
}

.lesson-topbar a:hover {
  color: #115e59;
}

.lesson-topbar .lesson-title {
  font-weight: 900;
  color: var(--ink);
  letter-spacing: 0.02em;
}

.page {
  max-width: 1380px;
  margin: 0 auto;
  display: grid;
  gap: 14px;
}

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.problem {
  padding: 14px 16px;
  display: grid;
  gap: 8px;
  font-size: 14px;
  line-height: 1.7;
}

.problem-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.problem-summary-text {
  font-weight: 900;
  color: #0f172a;
}

.problem-toggle {
  flex: 0 0 auto;
  background: linear-gradient(135deg, #0f766e, #14b8a6);
  font-size: 12px;
  padding: 7px 12px;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 800;
  color: #fff;
}

.problem-full {
  display: grid;
  gap: 8px;
}

.problem.collapsed .problem-full {
  display: none;
}

.problem-line {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 12px;
}

.problem-line > span:first-child {
  flex: 1 1 60%;
  min-width: 0;
}

.answer-chip {
  display: none;
  flex: 0 0 auto;
  align-self: baseline;
  justify-content: center;
  width: max-content;
  max-width: 100%;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(15, 118, 110, 0.1);
  border: 1px solid rgba(15, 118, 110, 0.18);
  color: #115e59;
  font-size: 12px;
  font-weight: 800;
  line-height: 1.4;
  text-align: center;
  white-space: nowrap;
  overflow-wrap: anywhere;
}

.answer-chip.show {
  display: inline-flex;
}

/* 原题图形组：外层是一个白色大卡片，内部 grid 装多张图 */
.problem-original-figures {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin-top: 8px;
  padding: 16px;
  background: #fff;
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 10px;
}

/* 只有一张图时：去掉外层卡片间距，让单图直接显示自己的白底和边框 */
.problem-original-figures:has(.problem-figure:only-child) {
  display: block;
  padding: 0;
  background: transparent;
  border: none;
}

.problem-original-figures:has(.problem-figure:only-child) .problem-figure {
  align-items: flex-start;
}

.problem-original-figures:has(.problem-figure:only-child) .problem-figure svg {
  background: #fff;
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 10px;
  max-width: 360px;
  margin: 0;
}

/* 单张图：去掉自己的边框/背景，只是布局单元 */
.problem-figure {
  margin: 0;
  background: transparent;
  border: none;
  border-radius: 0;
  overflow: visible;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.problem-figure svg {
  width: 100%;
  height: 180px;
  display: block;
  background: #fff;
}

/* 图标题：图下方第一行 */
.problem-figure h3 {
  margin: 6px 0 0 0;
  padding: 0;
  border: none;
  font-size: 14px;
  font-weight: 700;
  color: #334155;
  text-align: center;
}

/* 图说明：图下方第二行（更小、更淡） */
.problem-figure-caption {
  margin: 2px 0 0 0;
  font-size: 13px;
  color: #6b7280;
  text-align: center;
  line-height: 1.4;
}

@media (max-width: 640px) {
  .problem-original-figures {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    padding: 12px;
    gap: 12px;
  }

  .problem-figure svg {
    height: 160px;
  }
}

.lesson-nav {
  padding: 10px 14px;
  display: grid;
  gap: 8px;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(560px, 1.2fr) minmax(320px, 0.8fr);
  gap: 14px;
  align-items: start;
}

.diagram,
.panel {
  padding: 14px;
  display: grid;
  gap: 10px;
}

.svg-wrap {
  overflow: auto;
  border-radius: 16px;
}

svg {
  width: 100%;
  display: block;
  border-radius: 16px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(255, 248, 240, 0.96));
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  color: var(--muted);
  font-size: 13px;
}

.legend span {
  display: inline-flex;
  gap: 7px;
  align-items: center;
}

.sw {
  width: 12px;
  height: 12px;
  border-radius: 4px;
  border: 1px solid rgba(15, 23, 42, 0.18);
}

.sw-paper {
  background: var(--paper);
  border-color: var(--paper-stroke);
}

.sw-fold {
  background: var(--fold);
  border-color: var(--fold-stroke);
}

.sw-overlap {
  background: var(--overlap);
  border-color: var(--overlap-stroke);
}

.geom-grid-line {
  stroke: rgba(15, 23, 42, 0.06);
  stroke-width: 1;
}

.geom-axis {
  stroke: #93a0ad;
  stroke-width: 2;
}

.geom-axis-label {
  fill: #64748b;
  font-size: 19px;
  font-weight: 900;
}

.geom-axis-marker {
  fill: #64748b;
}

.geom-fixed {
  fill: var(--paper);
  stroke: var(--paper-stroke);
  stroke-width: 3;
}

.geom-original {
  fill: rgba(245, 158, 11, 0.1);
  stroke: var(--paper-stroke);
  stroke-width: 2.4;
  stroke-dasharray: 8 7;
}

.geom-moving {
  fill: var(--fold);
  stroke: var(--fold-stroke);
  stroke-width: 3;
}

.geom-overlap {
  fill: var(--overlap);
  stroke: var(--overlap-stroke);
  stroke-width: 3;
}

.geom-overlap-guide {
  stroke: var(--overlap-stroke);
  stroke-width: 3;
}

.geom-area-cut {
  fill: rgba(245, 158, 11, 0.28);
  stroke: var(--warn);
  stroke-width: 2.2;
  stroke-dasharray: 6 5;
}

.geom-translation-guide {
  stroke: var(--accent);
  stroke-width: 2.6;
  stroke-dasharray: 8 6;
}

.geom-angle-guide {
  fill: none;
  stroke: #dc2626;
  stroke-width: 3;
}

.geom-angle-label,
.geom-overlap-label {
  fill: #dc2626;
  font-weight: 900;
}

.geom-angle-label {
  font-size: 20px;
}

.geom-angle-label-small {
  font-size: 14px;
}

.geom-overlap-label {
  font-size: 18px;
}

.geom-fixed-point,
.geom-moving-point {
  stroke: #fff;
  stroke-width: 2.4;
}

.geom-fixed-point {
  fill: #1f2937;
}

.geom-moving-point {
  fill: var(--fold-stroke);
}

.geom-result-box {
  fill: rgba(255, 255, 255, 0.95);
  stroke: #475569;
  stroke-width: 1.4;
}

.geom-result-top-right {
  transform: translate(742px, 56px);
}

.geom-result-text {
  fill: #111827;
  font-size: 14px;
  font-weight: 900;
}

.geom-mini-bg {
  fill: rgba(255, 255, 255, 0.72);
}

.geom-mini-axis {
  stroke: #94a3b8;
  stroke-width: 1.5;
}

.geom-mini-fixed {
  fill: var(--paper);
  stroke: var(--paper-stroke);
  stroke-width: 1.8;
}

.geom-mini-moving {
  fill: var(--fold);
  stroke: var(--fold-stroke);
  stroke-width: 1.8;
}

.geom-mini-overlap {
  fill: var(--overlap);
  stroke: var(--overlap-stroke);
  stroke-width: 1.8;
}

.step-nav {
  display: grid;
  gap: 8px;
}

.step-group {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 8px;
  align-items: center;
}

.step-group:first-child {
  grid-template-columns: 110px 1fr auto;
}

.step-group-title {
  font-size: 12px;
  font-weight: 900;
  color: #475569;
}

.step-dots {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.step-connector {
  width: 16px;
  height: 2px;
  border-radius: 99px;
  background: #cbd5e1;
}

.step-dot {
  min-width: 62px;
  height: 28px;
  border-radius: 999px;
  padding: 0 10px;
  display: inline-grid;
  place-items: center;
  background: #e2e8f0;
  color: #475569;
  border: 1px solid rgba(71, 85, 105, 0.18);
  font-size: 12px;
  white-space: nowrap;
}

.step-dot.done {
  background: #dff4ed;
  color: #0f766e;
}

.step-dot.active {
  background: #0f766e;
  color: #fff;
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.14);
}

.nav-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.step-head {
  display: grid;
  gap: 4px;
}

.step-section {
  display: inline-flex;
  align-items: center;
  justify-self: start;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(15, 118, 110, 0.1);
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.panel h2 {
  margin: 0;
  font-size: 19px;
}

.derive-list {
  display: grid;
  gap: 8px;
}

.derive-line {
  font-size: 14px;
  line-height: 1.62;
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
}

.derive-line strong {
  color: var(--accent);
  margin-right: 8px;
}

.derive-ref {
  margin-left: 10px;
  border: 1px solid rgba(37, 99, 235, 0.22);
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.08);
  color: var(--accent);
  font: 700 12px/1.2 var(--sans);
  padding: 3px 8px;
  cursor: pointer;
  vertical-align: 1px;
}

.derive-ref:hover,
.derive-ref:focus-visible {
  background: rgba(37, 99, 235, 0.14);
  outline: none;
}

.mini-boundaries {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.mini-boundaries[hidden] {
  display: none !important;
}

.mini-card {
  border-radius: 10px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.82);
  padding: 6px;
  display: grid;
  gap: 4px;
}

.mini-card[data-t] {
  cursor: pointer;
  transition: transform 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.mini-card[data-t]:hover {
  transform: translateY(-1px);
  border-color: rgba(15, 118, 110, 0.35);
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.08);
}

.mini-card.active {
  border-color: #0f766e;
  background: #eef7f2;
}

.mini-card h3 {
  margin: 0;
  font-size: 12px;
  color: var(--warn);
}

.mini-card p {
  margin: 0;
  font-size: 11px;
  line-height: 1.35;
  color: var(--muted);
}

.tools {
  padding: 12px 14px;
  display: grid;
  gap: 12px;
}

.tool-block {
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 16px;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.62);
  display: grid;
  gap: 10px;
}

.tool-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}

.tool-title {
  font-size: 13px;
  font-weight: 900;
  color: #0f766e;
  letter-spacing: 0.04em;
}

.btns {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.p-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.p-control {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 320px;
  flex: 1;
}

.p-control[hidden] {
  display: none;
}

.p-control input[type="range"] {
  width: 240px;
  max-width: min(260px, 100%);
  accent-color: var(--accent);
}

.milestones {
  width: 100%;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.milestones[hidden] {
  display: none;
}

.milestone-label {
  font-size: 13px;
  font-weight: 800;
  color: #64748b;
  margin-right: 2px;
}

.milestone-btn {
  border: 1px solid rgba(15, 118, 110, 0.24);
  background: #eef7f2;
  color: #0f766e;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 13px;
  cursor: pointer;
  font-weight: 700;
}

.milestone-btn.active {
  background: #0f766e;
  color: #fff;
}

.status {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

svg .area-formula-bg {
  fill: rgba(255, 251, 245, 0.92);
  stroke: rgba(120, 53, 15, 0.18);
  stroke-width: 1.4;
}

svg .area-formula-text {
  fill: #1f2937;
  font-size: 17px;
  font-weight: 800;
}

svg .area-formula-target {
  fill: var(--overlap-stroke);
}

svg .area-formula-base {
  fill: var(--accent);
}

svg .area-formula-cut {
  fill: var(--warn);
}

svg .area-formula-op {
  fill: #64748b;
}

button {
  border: 0;
  cursor: pointer;
  border-radius: 999px;
  padding: 9px 14px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #0f766e, #155e75);
}

button.secondary {
  background: linear-gradient(135deg, #334155, #475569);
}

button.warn {
  background: linear-gradient(135deg, #b45309, #d97706);
}

button.move-on {
  background: linear-gradient(135deg, #0f766e, #14b8a6);
}

button.move-off {
  background: linear-gradient(135deg, #b45309, #d97706);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
  filter: saturate(0.5);
}

@media (max-width: 1000px) {
  .workspace {
    grid-template-columns: 1fr;
  }

  .step-group,
  .step-group:first-child {
    grid-template-columns: 1fr;
  }

  .nav-buttons {
    justify-content: flex-start;
  }

  .problem-line > span:first-child {
    flex-basis: 100%;
  }

  .mini-boundaries {
    grid-template-columns: 1fr;
  }
}

/*
  全步骤展开题页布局
  用于 internal/templates/interactive-problem-page.template.html 和南开式题目页。
*/

.page-with-rail {
  max-width: 1460px;
}

.lesson-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 248px;
  gap: 14px;
  align-items: start;
}

.lesson-flow,
.all-steps {
  min-width: 0;
  display: grid;
  gap: 14px;
}

.lesson-step-card {
  scroll-margin-top: 16px;
  padding: 14px;
  display: grid;
  gap: 12px;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.lesson-step-card.active-step {
  border-color: rgba(15, 118, 110, 0.34);
  box-shadow: 0 18px 54px rgba(15, 118, 110, 0.14);
}

.step-card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.step-card-title {
  min-width: 0;
  display: grid;
  gap: 6px;
}

.step-card-title h2 {
  margin: 0;
  color: #0f172a;
  font-size: 21px;
  line-height: 1.3;
}

.step-card-index {
  flex: 0 0 auto;
  min-width: 46px;
  padding: 5px 10px;
  border-radius: 999px;
  background: rgba(15, 118, 110, 0.1);
  color: var(--accent);
  font-size: 13px;
  font-weight: 900;
  text-align: center;
}

.step-card-body {
  display: grid;
  grid-template-columns: minmax(440px, 1.1fr) minmax(300px, 0.9fr);
  gap: 14px;
  align-items: start;
}

.step-card-diagram,
.step-card-panel {
  display: grid;
  gap: 10px;
}

.step-card-panel {
  padding: 12px;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.58);
}

.step-local-tools {
  display: grid;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid rgba(15, 118, 110, 0.14);
  border-radius: 14px;
  background: rgba(238, 247, 242, 0.72);
}

.step-slider-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: nowrap;
}

.step-slider-row label {
  color: var(--accent);
  font-size: 13px;
  font-weight: 900;
  white-space: nowrap;
}

.step-slider-row input[type="range"] {
  flex: 1;
  min-width: 180px;
  accent-color: var(--accent);
}

.step-t-value {
  min-width: 72px;
  color: #0f172a;
  font-size: 13px;
  font-weight: 900;
  text-align: right;
  white-space: nowrap;
}

.step-local-note {
  color: #64748b;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.45;
}

.lesson-step-card .mini-boundaries {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 8px 10px;
  border: 1px solid rgba(15, 118, 110, 0.12);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.5);
}

.mini-jump-row {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 2px;
  scrollbar-width: none;
}

.mini-jump-row::-webkit-scrollbar {
  display: none;
}

.mini-jump {
  flex: 0 0 auto;
  border: 1px solid rgba(15, 118, 110, 0.22);
  border-radius: 999px;
  background: rgba(238, 247, 242, 0.82);
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
  padding: 6px 10px;
  cursor: pointer;
}

.mini-jump.active {
  background: var(--accent);
  color: #fff;
}

.mini-preview-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 8px;
}

.mini-card {
  cursor: pointer;
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.mini-card:hover {
  transform: translateY(-1px);
  border-color: rgba(15, 118, 110, 0.36);
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.08);
}

.lesson-rail {
  position: sticky;
  top: 14px;
  max-height: calc(100vh - 28px);
  overflow: auto;
  padding: 14px;
  display: grid;
  gap: 12px;
}

.rail-kicker {
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.rail-title {
  margin: 0;
  color: #0f172a;
  font-size: 20px;
  line-height: 1.2;
}

.rail-progress {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  color: #64748b;
  font-size: 12px;
  font-weight: 800;
}

.rail-progress-bar {
  flex: 1;
  height: 6px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.28);
  overflow: hidden;
}

.rail-progress-fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #0f766e, #14b8a6);
  transition: width 0.2s ease;
}

.lesson-rail .step-nav {
  gap: 12px;
}

.lesson-rail .step-group,
.lesson-rail .step-group:first-child {
  grid-template-columns: 1fr;
  gap: 7px;
  align-items: stretch;
}

.lesson-rail .step-group-title {
  color: #0f172a;
  font-size: 13px;
}

.lesson-rail .step-dots {
  display: grid;
  gap: 6px;
}

.lesson-rail .step-connector {
  display: none;
}

.lesson-rail .step-dot {
  width: 100%;
  min-width: 0;
  height: auto;
  min-height: 34px;
  justify-content: start;
  place-items: center start;
  border-radius: 12px;
  padding: 8px 10px;
  text-align: left;
  white-space: normal;
}

.mobile-step-dock,
.mobile-step-sheet {
  display: none;
}

@media (max-width: 1180px) {
  .lesson-layout {
    grid-template-columns: minmax(0, 1fr) 220px;
  }

  .step-card-body {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 860px) {
  body {
    padding-bottom: 96px;
  }

  .lesson-layout {
    display: block;
  }

  .lesson-rail {
    display: none;
  }

  .mobile-step-dock {
    position: fixed;
    left: 12px;
    right: 12px;
    bottom: 12px;
    z-index: 40;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 12px;
    border: 1px solid rgba(15, 118, 110, 0.2);
    border-radius: 18px;
    background: rgba(255, 251, 245, 0.96);
    box-shadow: 0 18px 48px rgba(15, 23, 42, 0.18);
    backdrop-filter: blur(14px);
  }

  .mobile-step-current {
    min-width: 0;
    display: grid;
    gap: 3px;
  }

  .mobile-step-count {
    color: var(--accent);
    font-size: 11px;
    font-weight: 900;
    white-space: nowrap;
  }

  .mobile-step-name {
    overflow: hidden;
    color: #0f172a;
    font-size: 14px;
    font-weight: 900;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .mobile-step-toggle {
    flex: 0 0 auto;
    padding: 9px 14px;
  }

  .mobile-step-sheet {
    position: fixed;
    inset: auto 0 0;
    z-index: 50;
    display: block;
    padding: 10px 12px 14px;
    background: rgba(15, 23, 42, 0.24);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.18s ease;
  }

  .mobile-step-sheet.open {
    opacity: 1;
    pointer-events: auto;
  }

  .mobile-step-panel {
    max-height: min(72vh, 560px);
    overflow: auto;
    border: 1px solid rgba(120, 53, 15, 0.16);
    border-radius: 24px;
    background: #fffaf2;
    box-shadow: 0 -18px 56px rgba(15, 23, 42, 0.2);
    padding: 10px 14px 16px;
    transform: translateY(12px);
    transition: transform 0.18s ease;
  }

  .mobile-step-sheet.open .mobile-step-panel {
    transform: translateY(0);
  }

  .mobile-sheet-handle {
    width: 42px;
    height: 4px;
    margin: 2px auto 12px;
    border-radius: 999px;
    background: rgba(100, 116, 139, 0.35);
  }

  .mobile-sheet-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 12px;
  }

  .mobile-sheet-head h2 {
    margin: 0;
    color: #0f172a;
    font-size: 18px;
  }

  .mobile-step-sheet .step-nav {
    gap: 12px;
  }

  .mobile-step-sheet .step-group,
  .mobile-step-sheet .step-group:first-child {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .mobile-step-sheet .step-dots {
    display: flex;
    gap: 7px;
    flex-wrap: wrap;
  }

  .mobile-step-sheet .step-connector,
  .mobile-step-sheet .nav-buttons {
    display: none;
  }

  .mobile-step-sheet .step-dot {
    min-width: 0;
  }

  .step-card-title h2 {
    font-size: 18px;
  }

  .step-card-head {
    display: flex;
    align-items: flex-start;
    gap: 8px;
  }

  .step-card-body {
    grid-template-columns: 1fr;
  }

  .step-card-index {
    margin-top: 2px;
    min-width: auto;
    padding: 3px 7px;
    font-size: 11px;
    line-height: 1.2;
    white-space: nowrap;
  }

  .step-local-tools {
    padding: 8px 10px;
  }

  .step-slider-row {
    flex-wrap: nowrap;
    gap: 7px;
  }

  .step-slider-row label {
    flex: 0 0 auto;
    max-width: 82px;
    overflow: hidden;
    font-size: 12px;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .step-slider-row input[type="range"] {
    flex: 1 1 auto;
    min-width: 0;
  }

  .step-t-value {
    min-width: 56px;
    font-size: 12px;
  }

  .step-local-note,
  .mini-jump-row {
    display: none;
  }

  .lesson-step-card .mini-boundaries {
    gap: 6px;
    margin-top: -2px;
    padding: 7px 8px;
  }

  .mini-preview-strip {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 2px;
    scroll-snap-type: x proximity;
    scrollbar-width: none;
  }

  .mini-preview-strip::-webkit-scrollbar {
    display: none;
  }

  .mini-preview-strip .mini-card {
    flex: 0 0 128px;
    min-width: 128px;
    padding: 6px;
    gap: 4px;
    scroll-snap-align: start;
  }

  .mini-preview-strip .mini-card svg {
    display: block;
    width: 100%;
    height: 58px;
    border-radius: 8px;
    background: rgba(255, 251, 245, 0.78);
  }

  .mini-preview-strip .mini-card h3 {
    font-size: 12px;
    line-height: 1.15;
  }

  .mini-preview-strip .mini-card p {
    display: none;
  }
}