:root {
  --bg: #f4f6f3;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-strong: rgba(251, 252, 251, 0.98);
  --line: rgba(15, 33, 27, 0.1);
  --line-strong: rgba(15, 33, 27, 0.16);
  --ink: #102019;
  --muted: #5c6a63;
  --accent: #0f8c6c;
  --accent-strong: #0b6c53;
  --shadow: 0 18px 44px rgba(16, 32, 25, 0.08);
  --mono: "IBM Plex Mono", monospace;
  --sans: "IBM Plex Sans", "IBM Plex Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  font-family: var(--sans);
  background:
    radial-gradient(circle at 10% 0%, rgba(15, 140, 108, 0.18), transparent 24%),
    radial-gradient(circle at 85% 12%, rgba(233, 212, 183, 0.32), transparent 22%),
    linear-gradient(180deg, #f8faf8 0%, var(--bg) 100%);
}

.noise {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(15, 33, 27, 0.024) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 33, 27, 0.024) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.8), transparent 92%);
}

.site-shell {
  position: relative;
  width: min(1360px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0 56px;
}

.site-header {
  position: sticky;
  top: 12px;
  z-index: 30;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 16px;
  margin-bottom: 18px;
  background: rgba(252, 253, 252, 0.92);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: var(--ink);
  text-decoration: none;
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 82px;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  color: var(--accent-strong);
  background: rgba(15, 140, 108, 0.1);
  border: 1px solid rgba(15, 140, 108, 0.16);
  border-radius: 999px;
}

.brand strong {
  display: block;
  font-size: 1rem;
  font-weight: 700;
}

.brand p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.86rem;
}

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

.main-nav a,
.button,
.quick-entry,
.share-button,
.lesson-tab,
.mini-link {
  font: inherit;
}

.main-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 10px 14px;
  color: var(--muted);
  text-decoration: none;
  border-radius: 999px;
  transition: 0.2s ease;
}

.nav-short {
  display: none;
}

body[data-page="landing"] .main-nav a[data-nav="landing"],
body[data-page="class"] .main-nav a[data-nav="class"],
body[data-page="course"] .main-nav a[data-nav="course"],
body[data-page="assignment"] .main-nav a[data-nav="assignment"],
body[data-page="showcase"] .main-nav a[data-nav="showcase"],
body[data-page="community"] .main-nav a[data-nav="community"],
body[data-page="assessment"] .main-nav a[data-nav="assessment"] {
  color: var(--ink);
  background: rgba(15, 140, 108, 0.1);
}

.main-nav a:hover,
.button:hover,
.quick-entry:hover,
.share-button:hover,
.lesson-tab:hover {
  transform: translateY(-1px);
}

.page-main,
.product-main {
  display: grid;
  gap: 18px;
}

.product-main > *[id],
.page-main > *[id],
.workspace-card[id],
.lesson-sidebar[id],
.chat-panel[id],
.chat-sidebar[id] {
  scroll-margin-top: 110px;
}

.landing-hero,
.dashboard-hero,
.page-section,
.workspace-card,
.panel,
.lesson-sidebar,
.lesson-stage {
  position: relative;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.page-jump-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 14px 16px;
  background: rgba(250, 252, 250, 0.86);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.page-jump-bar a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 9px 14px;
  color: var(--ink);
  text-decoration: none;
  background: rgba(15, 140, 108, 0.08);
  border: 1px solid rgba(15, 140, 108, 0.1);
  border-radius: 999px;
  transition: 0.2s ease;
}

.page-jump-bar a:hover {
  transform: translateY(-1px);
}

.landing-hero,
.dashboard-hero,
.page-section {
  padding: 30px;
}

.landing-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.88fr);
  gap: 20px;
  min-height: auto;
  align-items: start;
  padding-top: 28px;
  padding-bottom: 28px;
}

.dashboard-hero {
  display: grid;
  gap: 20px;
}

.hero-copy h1,
.dashboard-hero h1,
.section-head h2,
.workspace-card h2,
.feature-card h3,
.panel h3,
.timeline-card h3,
.work-card h3,
.course-block h3 {
  margin: 0 0 12px;
  letter-spacing: -0.03em;
  line-height: 1.08;
}

.hero-copy h1 {
  max-width: 9.2em;
  font-size: clamp(1.9rem, 3vw, 2.95rem);
  line-height: 1.08;
}

.dashboard-hero h1 {
  max-width: 12em;
  font-size: clamp(1.72rem, 2.35vw, 2.35rem);
  line-height: 1.12;
}

.section-head h2 {
  max-width: 15em;
  font-size: clamp(1.56rem, 2.5vw, 2.35rem);
}

.eyebrow,
.module-label,
.panel-kicker,
.status-pill,
.mini-link,
.metric-row,
.stat-card span {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.eyebrow,
.panel-kicker,
.module-label {
  margin: 0 0 12px;
  color: var(--accent-strong);
  text-transform: uppercase;
}

.hero-text,
.section-text,
.feature-card p,
.timeline-card p,
.workspace-card p,
.panel p,
.clean-list li,
.mini-card p,
.chat-message p,
.assistant-subtitle {
  color: var(--muted);
  line-height: 1.75;
}

.hero-text {
  max-width: 42rem;
  margin: 16px 0 0;
  font-size: 1rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 13px 18px;
  text-decoration: none;
  border-radius: 16px;
  transition: 0.2s ease;
}

.button-solid {
  color: #f6fffb;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
}

.button-ghost {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.58);
  border: 1px solid var(--line-strong);
}

.module-stack,
.feature-grid,
.timeline-grid,
.dashboard-grid,
.split-grid,
.quick-grid,
.showcase-grid,
.score-grid,
.stats-row,
.mini-cards,
.agenda-list,
.progress-list,
.course-blocks,
.chat-feed {
  display: grid;
  gap: 16px;
}

.module-card,
.feature-card,
.timeline-card,
.mini-card,
.score-card,
.feedback-card,
.group-item,
.work-card,
.chat-message,
.agenda-item,
.quick-entry,
.stat-card {
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: 22px;
}

.module-card,
.feature-card,
.timeline-card,
.workspace-card,
.panel {
  padding: 22px;
}

.sample-work-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.sample-work-card {
  display: grid;
  gap: 14px;
  color: var(--ink);
  text-decoration: none;
  padding: 16px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: 22px;
  transition: 0.2s ease;
}

.sample-work-card:hover {
  transform: translateY(-2px);
}

.sample-work-media {
  aspect-ratio: 1.24 / 1;
  overflow: hidden;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(15, 140, 108, 0.05);
}

.sample-work-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.sample-work-body {
  display: grid;
  gap: 6px;
}

.sample-work-body strong {
  font-size: 1rem;
}

.sample-work-body p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.module-card-accent {
  background: linear-gradient(145deg, rgba(15, 140, 108, 0.14), rgba(233, 212, 183, 0.25));
}

.feature-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-card,
.timeline-card {
  display: block;
  color: var(--ink);
  text-decoration: none;
}

.timeline-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.split-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.dashboard-grid {
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.workspace-card {
  grid-column: span 4;
}

.workspace-card-large {
  grid-column: span 8;
}

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(15, 33, 27, 0.08);
}

.mini-link {
  color: var(--accent-strong);
  text-decoration: none;
}

.stats-row,
.progress-list {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.stat-card,
.feedback-card,
.mini-card,
.work-card,
.score-card,
.chat-message {
  padding: 16px;
}

.stat-card strong,
.progress-list strong {
  display: block;
  margin: 12px 0 8px;
  font-size: 1.55rem;
}

.stat-card p {
  margin: 0;
}

.agenda-item {
  display: flex;
  gap: 14px;
  padding: 16px;
}

.agenda-item span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  color: var(--accent-strong);
  font-family: var(--mono);
  background: rgba(15, 140, 108, 0.12);
  border-radius: 12px;
}

.quick-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.quick-entry {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 76px;
  padding: 16px;
  color: var(--ink);
  text-decoration: none;
  background: rgba(255, 255, 255, 0.74);
  border: 1px dashed var(--line-strong);
  border-radius: 18px;
  transition: 0.2s ease;
}

.activity-feed {
  display: grid;
  gap: 12px;
}

.activity-item {
  padding: 14px 16px;
  background: rgba(255, 255, 255, 0.68);
  border: 1px solid var(--line);
  border-radius: 18px;
}

.activity-item strong {
  display: inline-flex;
  margin-bottom: 8px;
  color: var(--accent-strong);
  font-family: var(--mono);
  font-size: 0.78rem;
}

.identity-card {
  display: grid;
  gap: 14px;
}

.identity-card strong {
  font-size: 1.08rem;
}

.clean-list {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 10px;
}

.lesson-layout,
.chat-layout {
  display: grid;
  gap: 18px;
}

.lesson-layout {
  grid-template-columns: 280px minmax(0, 1fr);
  align-items: start;
}

.chat-layout {
  grid-template-columns: 260px minmax(0, 1fr) 260px;
}

.lesson-sidebar {
  display: grid;
  gap: 10px;
  padding: 22px;
  position: sticky;
  top: 108px;
  align-self: start;
  height: fit-content;
}

.lesson-tab {
  width: 100%;
  min-height: 52px;
  padding: 14px 16px;
  color: var(--ink);
  text-align: left;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: 18px;
  cursor: pointer;
}

.lesson-tab.is-active,
.group-item.is-active {
  background: rgba(15, 140, 108, 0.12);
}

.lesson-stage {
  padding: 0;
}

.lesson-sheet {
  display: none;
  padding: 24px;
}

.lesson-sheet.is-active {
  display: block;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 12px;
  color: var(--accent-strong);
  background: rgba(15, 140, 108, 0.1);
  border-radius: 999px;
}

.status-pill-soft {
  color: var(--muted);
  background: rgba(15, 33, 27, 0.06);
}

.metric-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
  color: var(--muted);
}

.course-block {
  padding: 18px;
  background: rgba(255, 255, 255, 0.66);
  border: 1px solid var(--line);
  border-radius: 20px;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

.prompt-chip {
  padding: 9px 12px;
  color: var(--ink);
  font: inherit;
  background: rgba(15, 140, 108, 0.08);
  border: 1px solid rgba(15, 140, 108, 0.12);
  border-radius: 999px;
  cursor: pointer;
}

.lab-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.7fr);
  gap: 14px;
}

.input-field {
  display: grid;
  gap: 8px;
}

.input-field span {
  color: var(--muted);
  font-size: 0.9rem;
}

.input-field input,
.input-field textarea {
  width: 100%;
  padding: 13px 14px;
  color: var(--ink);
  font: inherit;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line-strong);
  border-radius: 16px;
  outline: none;
}

.lab-preview,
.submission-receipt,
.work-meta {
  padding: 16px;
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid var(--line);
  border-radius: 18px;
}

.lab-preview span,
.submission-receipt strong {
  display: block;
  margin-bottom: 8px;
  color: var(--accent-strong);
}

.lab-preview strong {
  display: block;
  margin-bottom: 10px;
  line-height: 1.6;
}

.work-meta code {
  padding: 3px 8px;
  color: var(--accent-strong);
  font-family: var(--mono);
  background: rgba(15, 140, 108, 0.08);
  border-radius: 999px;
}

.progress-list div {
  padding: 16px;
  background: rgba(255, 255, 255, 0.66);
  border: 1px solid var(--line);
  border-radius: 18px;
}

.progress-list span,
.work-actions span,
.group-item span {
  display: block;
  color: var(--muted);
}

.showcase-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.work-preview {
  aspect-ratio: 1.16 / 1;
  margin-bottom: 14px;
  overflow: hidden;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(15, 140, 108, 0.05);
}

.work-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.work-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.work-meta-line,
.source-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.65;
}

.source-note {
  margin-top: 18px;
}

.work-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 14px;
}

.share-button {
  min-height: 42px;
  padding: 10px 12px;
  color: var(--ink);
  background: rgba(15, 140, 108, 0.08);
  border: 1px solid rgba(15, 140, 108, 0.16);
  border-radius: 14px;
  cursor: pointer;
}

.inset-panel {
  padding: 18px;
  background: rgba(252, 253, 252, 0.9);
  border-radius: 20px;
}

.assignment-form {
  display: grid;
  gap: 12px;
}

.toggle-row {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
}

.toggle-row input {
  width: 16px;
  height: 16px;
}

.chat-sidebar {
  display: grid;
  gap: 12px;
  align-content: start;
}

.group-item {
  padding: 14px;
}

.group-item strong,
.chat-message strong {
  display: block;
  margin-bottom: 6px;
}

.chat-panel {
  display: grid;
  gap: 16px;
}

.chat-feed {
  min-height: 420px;
}

.chat-message-system {
  color: var(--accent-strong);
  font-family: var(--mono);
  background: rgba(15, 140, 108, 0.08);
}

.chat-compose,
.assistant-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
}

.chat-compose input,
.assistant-form textarea {
  width: 100%;
  padding: 13px 14px;
  color: var(--ink);
  font: inherit;
  background: rgba(255, 255, 255, 0.84);
  border: 1px solid var(--line-strong);
  border-radius: 16px;
  outline: none;
}

.chat-compose button,
.assistant-form button {
  min-height: 48px;
  padding: 12px 16px;
  color: #f7fffb;
  font: inherit;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  border: 0;
  border-radius: 16px;
  cursor: pointer;
}

.score-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.assistant-widget {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 50;
}

.assistant-fab {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 18px;
  color: #f6fffb;
  font: inherit;
  font-weight: 600;
  background: linear-gradient(135deg, var(--ink), #1d3d31);
  border: 0;
  border-radius: 999px;
  box-shadow: 0 22px 44px rgba(16, 32, 25, 0.22);
  cursor: pointer;
}

.assistant-fab-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #8df1cf;
  box-shadow: 0 0 0 6px rgba(141, 241, 207, 0.14);
}

.assistant-panel {
  position: absolute;
  right: 0;
  bottom: 74px;
  width: min(390px, calc(100vw - 24px));
  max-height: min(76vh, 740px);
  display: grid;
  grid-template-rows: auto auto minmax(200px, 1fr) auto;
  gap: 14px;
  padding: 18px;
  background: rgba(250, 252, 250, 0.95);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: 0 32px 72px rgba(16, 32, 25, 0.18);
  backdrop-filter: blur(20px);
}

.assistant-panel[hidden] {
  display: none !important;
}

.assistant-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.assistant-title {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
}

.assistant-subtitle {
  margin: 6px 0 0;
}

.assistant-close {
  width: 34px;
  height: 34px;
  color: var(--muted);
  font: inherit;
  font-size: 1.3rem;
  background: rgba(16, 32, 25, 0.06);
  border: 0;
  border-radius: 50%;
  cursor: pointer;
}

.assistant-quick-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.assistant-quick-actions button {
  padding: 9px 12px;
  color: var(--ink);
  font: inherit;
  background: rgba(15, 140, 108, 0.08);
  border: 1px solid rgba(15, 140, 108, 0.12);
  border-radius: 999px;
  cursor: pointer;
}

.assistant-messages {
  display: grid;
  gap: 12px;
  min-height: 200px;
  overflow-y: auto;
}

.assistant-message {
  max-width: 88%;
}

.assistant-message p {
  margin: 0;
  padding: 12px 14px;
  white-space: pre-wrap;
  line-height: 1.7;
  border-radius: 18px;
}

.assistant-message-bot p {
  background: rgba(15, 140, 108, 0.08);
}

.assistant-message-user {
  justify-self: end;
}

.assistant-message-user p {
  color: #f7fffb;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1180px) {
  .landing-hero,
  .lesson-layout,
  .chat-layout {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .timeline-grid,
  .sample-work-grid,
  .showcase-grid,
  .score-grid,
  .stats-row,
  .progress-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .workspace-card,
  .workspace-card-large {
    grid-column: span 12;
  }

  .lesson-sidebar {
    order: 2;
  }

  .lesson-stage {
    order: 1;
  }

  .chat-panel {
    order: 1;
  }

  .chat-sidebar {
    order: 2;
  }

  .chat-layout > .workspace-card:last-child {
    order: 3;
  }

  .lesson-sidebar {
    position: static;
  }

  .lab-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .site-shell {
    width: min(100% - 16px, 1360px);
    padding-top: 10px;
    padding-bottom: 92px;
  }

  .site-header,
  .landing-hero,
  .dashboard-hero,
  .page-section,
  .workspace-card,
  .panel,
  .lesson-sidebar,
  .lesson-stage {
    padding: 18px;
    border-radius: 22px;
  }

  .site-header {
    top: 8px;
    gap: 12px;
    padding: 12px;
  }

  .brand {
    width: 100%;
    align-items: flex-start;
  }

  .brand-badge {
    min-width: 74px;
    padding: 9px 10px;
  }

  .main-nav {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 8px;
  }

  .main-nav a {
    min-height: 40px;
    width: 100%;
    padding: 9px 8px;
    font-size: 0.86rem;
    text-align: center;
  }

  .nav-full {
    display: none;
  }

  .nav-short {
    display: inline;
  }

  .product-main > *[id],
  .page-main > *[id],
  .workspace-card[id],
  .lesson-sidebar[id],
  .chat-panel[id],
  .chat-sidebar[id] {
    scroll-margin-top: 136px;
  }

  .landing-hero {
    min-height: auto;
  }

  .page-jump-bar {
    position: sticky;
    top: 84px;
    z-index: 18;
    flex-wrap: nowrap;
    overflow-x: auto;
    padding: 10px 12px;
    gap: 8px;
    scrollbar-width: none;
    -ms-overflow-style: none;
  }

  .page-jump-bar::-webkit-scrollbar {
    display: none;
  }

  .page-jump-bar a {
    flex: 0 0 auto;
    white-space: nowrap;
    min-height: 36px;
    padding: 8px 12px;
    font-size: 0.9rem;
  }

  .hero-copy h1 {
    max-width: none;
    font-size: clamp(1.72rem, 7vw, 2.2rem);
  }

  .dashboard-hero h1 {
    max-width: none;
    font-size: clamp(1.5rem, 5.8vw, 1.95rem);
  }

  .hero-text,
  .section-text {
    font-size: 0.98rem;
  }

  .feature-grid,
  .timeline-grid,
  .split-grid,
  .sample-work-grid,
  .showcase-grid,
  .score-grid,
  .stats-row,
  .progress-list,
  .quick-grid {
    grid-template-columns: 1fr;
  }

  .chat-compose,
  .assistant-form {
    grid-template-columns: 1fr;
  }

  .chat-feed {
    min-height: 280px;
  }

  .quick-entry {
    min-height: 64px;
  }

  .work-preview {
    aspect-ratio: 1.3 / 1;
  }

  .assistant-widget {
    right: 10px;
    bottom: 10px;
  }

  .assistant-fab {
    padding: 12px 16px;
  }

  .assistant-panel {
    right: 0;
    bottom: 64px;
    width: min(100vw - 12px, 390px);
    max-height: min(70vh, 620px);
    padding: 14px;
    border-radius: 20px;
  }
}

@media (max-width: 420px) {
  .site-shell {
    width: min(100% - 12px, 1360px);
    padding-bottom: 88px;
  }

  .site-header,
  .landing-hero,
  .dashboard-hero,
  .page-section,
  .workspace-card,
  .panel,
  .lesson-sidebar,
  .lesson-stage {
    padding: 16px;
    border-radius: 18px;
  }

  .hero-copy h1 {
    font-size: clamp(1.5rem, 7vw, 1.84rem);
  }

  .dashboard-hero h1 {
    font-size: clamp(1.34rem, 5.8vw, 1.62rem);
  }

  .page-jump-bar {
    top: 78px;
    padding: 8px 10px;
    border-radius: 16px;
  }

  .page-jump-bar a {
    min-height: 34px;
    padding: 7px 10px;
    font-size: 0.86rem;
  }

  .section-head h2 {
    font-size: clamp(1.45rem, 7vw, 2rem);
  }

  .stat-card strong,
  .progress-list strong {
    font-size: 1.32rem;
  }

  .assistant-widget {
    right: 8px;
    bottom: 8px;
  }

  .main-nav {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .assistant-fab {
    padding: 11px 14px;
    font-size: 0.92rem;
  }

  .assistant-panel {
    width: calc(100vw - 8px);
    right: -2px;
    bottom: 60px;
    padding: 12px;
  }
}