/* ============================================================
   US版ジェネレーターの「Quick start → 学年 → プリセット →
   左の設定 / 右のプレビュー」という操作の流れを日本語向けに再構成。
   既存の印刷紙面（.sheet）には影響させず、画面UIだけを上書きする。
   ============================================================ */

:root {
  --bg: #f6f8f7;
  --paper: #ffffff;
  --ink: #1e2d2a;
  --ink-soft: #5f706b;
  --muted: #7b8985;
  --line: #dfe7e4;
  --line-dark: #c8d6d1;
  --accent: #236b59;
  --accent-dark: #185244;
  --accent-soft: #edf7f3;
  --warm: #9a6a3a;
  --warm-soft: #f8f2e9;
  --shadow: 0 4px 14px rgba(24, 50, 43, 0.06);
  --radius: 10px;
  --radius-sm: 8px;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-size: 15px;
}

.container {
  max-width: 1200px;
}

.site-header {
  position: relative;
  background: #fff;
  border-bottom: 1px solid var(--line);
  backdrop-filter: none;
}
.header-inner {
  max-width: 1200px;
  padding: 10px 24px;
}
.logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--accent);
  box-shadow: none;
  font-size: 17px;
}
.logo-text {
  font-size: 16px;
  letter-spacing: 0.01em;
}
.logo-text small {
  font-size: 9px;
  letter-spacing: 0.08em;
}
.main-nav a {
  border-radius: 6px;
  font-size: 13px;
}
.header-cta {
  border-radius: 6px !important;
  box-shadow: none;
  padding: 8px 14px !important;
}
.menu-toggle {
  border-radius: 7px;
  box-shadow: none;
}

.btn {
  border-radius: 7px;
  min-height: 42px;
  box-shadow: none;
  font-size: 14px;
}
.btn-primary {
  background: var(--accent);
  box-shadow: none;
}
.btn-primary:hover {
  background: var(--accent-dark);
}
.btn-outline {
  border-color: var(--line-dark);
}

/* ---- ページ導入：US版と同じく、説明は短く ---- */
.compact-intro {
  padding: 26px 0 0;
}
.compact-intro .eyebrow {
  margin-bottom: 7px;
  font-size: 11px;
  letter-spacing: 0.1em;
}
.compact-intro h1 {
  margin: 0 0 8px;
  font-size: clamp(24px, 3.3vw, 34px);
  line-height: 1.4;
  letter-spacing: 0.015em;
}
.compact-intro .lead {
  margin: 0;
  max-width: 780px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}
.compact-top-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 11px;
}
.pill {
  border-color: var(--line);
  border-radius: 999px;
  background: #fff;
  font-size: 11px;
  padding: 2px 9px;
}

/* ---- クイックスタート ---- */
.quick-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: 18px 24px 0;
}
.quick-guide {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 28px;
  color: #546662;
  font-size: 12px;
}
.quick-guide__label {
  flex: 0 0 auto;
  color: #3a4a46;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.quick-guide__steps {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px;
  color: #667570;
}
.quick-guide__step {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
}
.quick-guide__step b,
.quick-guide__step strong {
  display: inline-grid;
  place-items: center;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  background: #e7efec;
  color: #3b5f55;
  font-size: 10px;
  font-weight: 800;
}
.quick-guide__arrow {
  color: #b2bfbb;
  font-size: 12px;
}
.quick-guide__link {
  margin-left: auto;
  font-size: 11px;
  font-weight: 700;
  color: #3b5f55;
  text-decoration: none;
  white-space: nowrap;
}
.quick-guide__link:hover {
  text-decoration: underline;
}

.quick-card {
  margin-top: 9px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 9px;
  overflow: hidden;
}
.quick-section {
  padding: 9px 20px 9px;
  border-bottom: 1px solid var(--line);
}
.quick-heading {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  color: #344641;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.1em;
}
.quick-number {
  color: #72827d;
}
.grade-tabs {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 7px;
  margin-top: 7px;
}
.grade-tab {
  min-height: 42px;
  padding: 7px 4px;
  border: 1px solid var(--line-dark);
  border-radius: 7px;
  background: #fff;
  color: #43534f;
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.2;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.grade-tab:hover {
  border-color: #82a79b;
  background: #fbfdfc;
}
.grade-tab.is-active {
  border-color: #8db9aa;
  background: var(--accent-soft);
  color: #1b5a4a;
  box-shadow: inset 0 0 0 1px rgba(35, 107, 89, 0.08);
}
.grade-tab small {
  display: block;
  margin-top: 1px;
  font-size: 9px;
  font-weight: 500;
  color: #7f918b;
}

.presets-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 4px 20px 1px;
  border-bottom: 0;
  background: #fff;
}
.preset-label {
  flex: 0 0 auto;
  color: #71817c;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}
.preset-chips {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  min-width: 0;
}
.preset-chip {
  min-height: 32px;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: #53645f;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  white-space: nowrap;
}
.preset-chip:hover {
  border-color: #8db9aa;
  color: var(--accent-dark);
}
.preset-chip.is-active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.quick-bottom {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 4px 20px 7px;
}
.quick-copy {
  flex: 1 1 auto;
  min-width: 0;
}
.quick-note {
  display: inline-block;
  width: fit-content;
  max-width: 100%;
  min-width: 0;
  padding: 8px 11px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  color: #38534b;
  font-size: 12px;
  line-height: 1.6;
}
.quick-note strong {
  color: #1f5143;
}
.quick-actions {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-right: clamp(40px, 15vw, 220px);
  /* 結合したプリセット行を含むブロックの中心へ寄せる */
  transform: translateY(-9px);
}
.quick-actions .btn {
  min-height: 40px;
  padding: 8px 16px;
  font-size: 13px;
  white-space: nowrap;
}
.quick-actions .btn-primary {
  min-width: 168px;
}
.quick-actions .btn-outline {
  min-width: 126px;
}
.quick-hint {
  margin: 0;
  padding: 5px 2px 0;
  color: #52665f;
  font-size: 12.5px;
  font-weight: 600;
  line-height: 1.5;
}

/* ---- 左の設定 / 右のプレビュー ---- */
.workspace-app {
  max-width: 1200px;
  margin: 0 auto 0;
  display: grid;
  grid-template-columns: 390px minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr);
  height: clamp(560px, calc(100vh - 300px), 700px);
  min-height: 0;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #fff;
  overflow: hidden;
}
.workspace-controls {
  padding: 14px 18px 10px;
  background: #fcfdfc;
  border-right: 1px solid var(--line);
  min-width: 0;
  min-height: 0;
  height: 100%;
  overflow-y: auto;
  scrollbar-width: thin;
}
.workspace-controls h2 {
  margin: 0;
  font-size: 13px;
  line-height: 1.4;
}
.workspace-form {
  display: flex;
  flex-direction: column;
  gap: 11px;
}
.workspace-study-tip {
  margin-top: 12px;
  padding: 9px 11px;
  border: 1px solid #dce8e2;
  border-radius: 7px;
  background: #f5faf7;
  color: #4d625a;
  font-size: 10.5px;
  line-height: 1.6;
}
.workspace-study-tip p {
  margin: 0;
}
.workspace-study-tip__label {
  margin-bottom: 3px !important;
  color: #236b59;
  font-weight: 700;
}
.workspace-study-tip__stumble {
  margin-top: 5px !important;
  color: #6b7d76;
}
.workspace-study-tip__stumble strong {
  color: #52665e;
}
.control-field {
  padding-bottom: 10px;
  border-bottom: 1px solid #edf1ef;
}
.control-field:last-of-type {
  border-bottom: 0;
  padding-bottom: 0;
}
.control-head {
  display: flex;
  align-items: baseline;
  gap: 7px;
  margin-bottom: 7px;
}
.control-head h2 {
  color: #374944;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.08em;
}
.control-step {
  color: #7c8d87;
  font-size: 10px;
  font-weight: 700;
}
.control-meta {
  margin-left: auto;
  color: #83918d;
  font-size: 10px;
  font-weight: 500;
}
.control-help {
  margin: 6px 0 0;
  color: #7d8c87;
  font-size: 10.5px;
  line-height: 1.6;
}
.unit-select {
  width: 100%;
  min-height: 40px;
  padding: 7px 34px 7px 11px;
  border: 1px solid var(--line-dark);
  border-radius: 6px;
  background: #fff;
  color: #344743;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, #5f706b 50%), linear-gradient(135deg, #5f706b 50%, transparent 50%);
  background-position: calc(100% - 17px) 18px, calc(100% - 12px) 18px;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
}
.unit-select:focus {
  outline: 2px solid rgba(35, 107, 89, 0.22);
  border-color: var(--accent);
}
.unit-path {
  display: block;
  margin-top: 5px;
  color: #8b9994;
  font-size: 10px;
}
.difficulty-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
}
.difficulty-btn {
  min-height: 45px;
  padding: 6px 4px;
  border: 1px solid var(--line-dark);
  border-radius: 6px;
  background: #fff;
  color: #465752;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.25;
  cursor: pointer;
}
.difficulty-btn span {
  display: block;
  margin-top: 1px;
  color: #87948f;
  font-size: 9px;
  font-weight: 500;
}
.difficulty-btn:hover {
  border-color: #8db9aa;
}
.difficulty-btn.is-active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
  box-shadow: none;
}
.difficulty-btn.is-active span {
  color: rgba(255,255,255,0.76);
}
.count-chips {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
}
.count-chip {
  min-height: 38px;
  padding: 5px;
  border: 1px solid var(--line-dark);
  border-radius: 6px;
  background: #fff;
  color: #465752;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
}
.count-chip:hover {
  border-color: #8db9aa;
}
.count-chip.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: #1d5b4b;
}
.answer-toggle {
  display: flex;
  align-items: center;
  gap: 7px;
  color: #53645f;
  font-size: 11px;
  cursor: pointer;
}
.answer-toggle input {
  width: 15px;
  height: 15px;
  accent-color: var(--accent);
}
.answer-toggle small {
  display: block;
  color: #87948f;
  font-size: 9.5px;
  font-weight: 400;
}
.generate-main {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  width: 100%;
  min-height: 49px;
  border: 0;
  border-radius: 7px;
  background: var(--accent);
  color: #fff;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
}
.generate-main:hover {
  background: var(--accent-dark);
}
.generate-main svg {
  width: 17px;
  height: 17px;
}
.control-actions {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 5px;
}
.control-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 33px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
  color: #465752;
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 600;
  cursor: pointer;
}
.control-action:hover {
  border-color: #8db9aa;
  color: var(--accent-dark);
}
.control-action svg {
  width: 13px;
  height: 13px;
}

/* preview */
.workspace-preview {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  height: 100%;
  overflow: hidden;
  background: #e9eeec;
}
.preview-toolbar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  min-height: 47px;
  padding: 8px 13px;
  border-bottom: 1px solid var(--line);
  background: #fff;
}
.preview-heading {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  margin-right: auto;
}
.preview-eyebrow {
  color: #5b6c67;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.1em;
  white-space: nowrap;
}
.preview-summary {
  color: #8a9894;
  font-size: 10px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.preview-actions {
  display: flex;
  align-items: center;
  gap: 5px;
}
.preview-page-select {
  min-height: 29px;
  max-width: 74px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
  color: #556660;
  font-family: var(--font-body);
  font-size: 10px;
}
.preview-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 29px;
  padding: 4px 9px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #fff;
  color: #53645f;
  font-family: var(--font-body);
  font-size: 10px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
}
.preview-btn:disabled,
.quick-actions .btn:disabled,
.control-action:disabled {
  opacity: 0.55;
  cursor: wait;
}
.pdf-staging {
  position: fixed;
  left: -10000px;
  top: 0;
  width: 210mm;
  background: #fff;
  z-index: -1;
  pointer-events: none;
}
.pdf-staging .sheet {
  margin: 0;
  border: 0;
  box-shadow: none;
}
.preview-btn:hover {
  border-color: #8db9aa;
  color: var(--accent-dark);
}
.preview-btn.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: #1d5b4b;
}
.preview-btn svg {
  width: 13px;
  height: 13px;
}
.preview-pager-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px 9px;
  padding: 9px 13px;
  border-bottom: 1px solid var(--line);
  background: #fbfcfb;
}
.preview-pager-label {
  color: #5b6c67;
  font-size: 11px;
  font-weight: 700;
  white-space: nowrap;
}
.preview-pager-select {
  min-height: 36px;
  min-width: 168px;
  padding: 6px 34px 6px 11px;
  border: 1px solid var(--line-dark);
  border-radius: 6px;
  background: #fff;
  color: #364944;
  font-family: var(--font-body);
  font-size: 12.5px;
  font-weight: 700;
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, #5f706b 50%), linear-gradient(135deg, #5f706b 50%, transparent 50%);
  background-position: calc(100% - 17px) 15px, calc(100% - 12px) 15px;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  cursor: pointer;
}
#preview-page-select {
  min-width: 220px;
}
#preview-zoom-select {
  min-width: 154px;
}
.preview-pager-select:focus {
  outline: 2px solid rgba(35, 107, 89, 0.22);
  border-color: var(--accent);
}
.preview-pager-note {
  margin-left: auto;
  color: #74847e;
  font-size: 10.5px;
  white-space: nowrap;
}
.preview-stage {
  flex: 1 1 auto;
  overflow: auto;
  padding: 16px;
  min-height: 0;
  scrollbar-color: #b7c7c0 transparent;
}
.preview-content {
  width: 100%;
  min-height: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: center;
}
.preview-sheet-wrap {
  flex: none;
  margin: 0 auto;
  overflow: hidden;
}
.preview-content .sheet {
  flex: none;
  margin: 0;
  border: 1px solid #d3ddd9;
  box-shadow: 0 5px 18px rgba(23, 43, 37, 0.12);
  transform-origin: top left;
}
.preview-content .sheet[hidden],
.preview-sheet-wrap[hidden] {
  display: none !important;
}
.preview-empty {
  width: min(430px, 90%);
  margin: 70px auto;
  padding: 30px;
  border: 1px dashed #b8c9c2;
  border-radius: 8px;
  background: #f8fbfa;
  text-align: center;
  color: #71827c;
  font-size: 12px;
}
.preview-empty strong {
  display: block;
  margin-bottom: 6px;
  color: #3b5f55;
  font-size: 14px;
}

/* examples */
.example-strip {
  max-width: 1200px;
  margin: 20px auto 0;
  padding: 0 24px;
}
.example-strip__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 9px;
}
.example-strip__head h2 {
  margin: 0;
  font-size: 15px;
}
.example-strip__head p {
  margin: 0;
  color: #7d8c87;
  font-size: 11px;
}
.example-strip .example-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 9px;
}
.example-strip .example-item {
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
  padding: 10px 11px;
}
.example-strip .example-number {
  color: #8b9994;
  font-size: 9px;
}
.example-strip .example-body .question-stem {
  font-size: 12px;
}
.example-strip .example-body .math-line {
  font-size: 16px;
}
.example-strip .example-body .answer-space {
  display: none;
}
.example-strip .example-body .hissan {
  font-size: 10px;
}
.example-strip .example-body .clock-svg {
  width: 65px;
  height: 65px;
}
.example-strip .example-body .shape-svg {
  width: 58px;
  height: 58px;
}

/* lower SEO content, sized like a supporting section */
.unit-content {
  max-width: 1200px;
  margin: 30px auto 0;
  padding: 0 24px;
}
.unit-content .content-grid {
  grid-template-columns: 1.55fr 0.8fr;
  gap: 28px;
}
.unit-content .prose h2 {
  margin-top: 24px;
  font-size: 19px;
}
.unit-content .prose p,
.unit-content .prose li {
  font-size: 13.5px;
  line-height: 1.9;
}
.unit-content .point-box,
.unit-content .tip-box {
  border-radius: 0 7px 7px 0;
  padding: 12px 14px;
}
.unit-content .side-panel {
  border-radius: 8px;
  padding: 14px;
}
.unit-content .side-panel h2 {
  font-size: 13px;
}
.unit-content .side-links a {
  font-size: 12px;
}

/* home lower sections */
.home-sections {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}
.home-sections .section {
  padding: 34px 0;
}
.home-sections .section-head h2 {
  font-size: 21px;
}
.home-sections .grade-grid {
  grid-template-columns: repeat(3, 1fr);
}
.home-sections .grade-card {
  border-radius: 8px;
  padding: 16px;
  box-shadow: none;
}
.home-sections .grade-card:hover {
  transform: none;
  box-shadow: 0 3px 12px rgba(24, 50, 43, 0.06);
}
.home-sections .unit-grid {
  grid-template-columns: repeat(2, 1fr);
}
.home-sections .unit-card {
  border-radius: 7px;
  padding: 12px 14px;
}
.home-sections .special-grid {
  grid-template-columns: repeat(4, 1fr);
}
.home-sections .special-card {
  border-radius: 8px;
  min-height: 126px;
  padding: 16px;
}
.home-sections .how-card {
  border-radius: 8px;
  padding: 16px;
}
.home-sections .faq-item summary {
  padding: 12px 30px 12px 0;
  font-size: 13px;
}

.mobile-preview {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: grid;
  place-items: center;
}
.mobile-preview[hidden] {
  display: none !important;
}
body.mobile-preview-open {
  overflow: hidden;
}
.mobile-preview__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(19, 36, 30, 0.58);
}
.mobile-preview__panel {
  position: relative;
  display: flex;
  flex-direction: column;
  width: min(720px, calc(100vw - 24px));
  height: min(90dvh, 900px);
  overflow: hidden;
  border-radius: 13px;
  background: #fff;
  box-shadow: 0 24px 70px rgba(11, 28, 22, 0.35);
}
.mobile-preview__head {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 50px;
  padding: 8px 12px 8px 15px;
  border-bottom: 1px solid var(--line);
  background: #fff;
}
.mobile-preview__head > div {
  display: flex;
  align-items: baseline;
  gap: 8px;
  min-width: 0;
  margin-right: auto;
}
.mobile-preview__eyebrow {
  color: #5b6c67;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
}
.mobile-preview__head strong {
  overflow: hidden;
  color: #364944;
  font-size: 11px;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.mobile-preview__close {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--line-dark);
  border-radius: 50%;
  background: #fff;
  color: #4c5e58;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
}
.mobile-preview__close:hover {
  background: #f3f8f5;
}
.mobile-preview__mount {
  display: flex;
  flex: 1 1 auto;
  min-height: 0;
}
.mobile-preview__mount .workspace-preview {
  width: 100%;
  height: 100%;
  min-height: 0;
  border-radius: 0;
}
.mobile-preview__mount .preview-heading {
  display: none;
}
.mobile-preview__mount .preview-actions {
  margin-left: auto;
}
.mobile-preview__mount .preview-toolbar {
  padding-right: 12px;
}
.mobile-preview__mount .preview-stage {
  padding: 12px;
}

@media (max-width: 860px) {
  .mobile-preview__panel {
    width: 100vw;
    height: 100dvh;
    border-radius: 0;
  }
}
@media (max-width: 1040px) {
  .workspace-app {
    grid-template-columns: 340px minmax(0, 1fr);
  }
  .quick-actions .btn-primary {
    min-width: 145px;
  }
  .quick-actions .btn-outline {
    min-width: 108px;
  }
  .home-sections .special-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 860px) {
  .workspace-app {
    grid-template-columns: 1fr;
    height: auto;
    min-height: 0;
  }
  .workspace-controls {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    overflow: visible;
  }
  .workspace-preview {
    min-height: 560px;
  }
  .preview-stage {
    max-height: 620px;
  }
  .quick-bottom {
    align-items: stretch;
    flex-direction: column;
    gap: 10px;
  }
  .quick-actions {
    justify-content: flex-end;
    margin-right: 0;
    transform: none;
  }
  .quick-note {
    width: 100%;
  }
  .unit-content .content-grid {
    grid-template-columns: 1fr;
  }
  .example-strip .example-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .header-inner {
    padding: 8px 14px;
  }
  .logo-text {
    font-size: 14px;
  }
  .logo-text small {
    display: block;
  }
  .quick-shell,
  .home-sections,
  .unit-content,
  .example-strip {
    padding-left: 14px;
    padding-right: 14px;
  }
  .compact-intro {
    padding-top: 18px;
  }
  .compact-intro h1 {
    font-size: 23px;
  }
  .compact-intro .lead {
    font-size: 13px;
  }
  .quick-guide {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }
  .quick-guide__steps {
    gap: 4px;
  }
  .quick-guide__step {
    font-size: 10px;
  }
  .quick-guide__step b {
    width: 15px;
    height: 15px;
  }
  .quick-guide__arrow {
    display: none;
  }
  .quick-guide__link {
    margin-left: 0;
  }
  .quick-section {
    padding: 14px 13px;
  }
  .grade-tabs {
    grid-template-columns: repeat(3, 1fr);
  }
  .grade-tab {
    min-height: 38px;
    font-size: 12px;
  }
  .presets-row {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
    padding: 9px 13px;
  }
  .preset-chips {
    gap: 5px;
  }
  .preset-label {
    font-size: 10px;
  }
  .preset-chip {
    font-size: 10px;
    padding: 5px 8px;
  }
  .quick-bottom {
    align-items: stretch;
    flex-direction: column;
    padding: 11px 13px;
  }
  .quick-actions {
    display: grid;
    grid-template-columns: 1fr;
  }
  .quick-actions .btn {
    width: 100%;
  }
  .quick-hint {
    padding: 4px 2px 0;
  }
  .workspace-app {
    margin-top: 12px;
    border-left: 0;
    border-right: 0;
    border-radius: 0;
  }
  .workspace-controls {
    padding: 14px 13px;
  }
  .preview-toolbar {
    padding: 7px 10px;
  }
  .preview-summary {
    display: none;
  }
  .preview-stage {
    padding: 10px;
  }
  .preview-pager-bar {
    padding: 8px 10px;
  }
  .preview-pager-select,
  #preview-page-select,
  #preview-zoom-select {
    flex: 1 1 120px;
    min-width: 0;
    min-height: 38px;
    font-size: 12px;
  }
  .preview-pager-label {
    font-size: 10px;
  }
  .preview-pager-note {
    flex: 1 1 100%;
    margin-left: 0;
    white-space: normal;
  }
  .home-sections .grade-grid,
  .home-sections .unit-grid,
  .home-sections .special-grid,
  .home-sections .how-grid {
    grid-template-columns: 1fr;
  }
  .example-strip {
    margin-top: 13px;
  }
}