:root {
  --blue: #0b63e5;
  --blue-soft: #eaf2ff;
  --ink: #182234;
  --muted: #667085;
  --surface: #ffffff;
  --canvas: #f5f7fa;
  --line: #dfe5ee;
  --coral: #f0645a;
  --coral-soft: #fff0ee;
  --success: #168a72;
  --success-soft: #e9f7f3;
  --radius: 8px;
  --tap: 44px;
  color-scheme: light;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--canvas);
}

body {
  min-width: 320px;
  min-height: 100dvh;
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font-size: 16px;
  line-height: 1.55;
  letter-spacing: 0;
}

button,
input,
textarea,
select {
  max-width: 100%;
  color: inherit;
  font: inherit;
  letter-spacing: 0;
}

button,
select {
  min-height: var(--tap);
}

button {
  cursor: pointer;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 3px solid #9bc2fb;
  outline-offset: 2px;
}

[hidden] {
  display: none !important;
}

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

.offline-notice {
  position: fixed;
  z-index: 40;
  top: max(8px, env(safe-area-inset-top));
  left: 50%;
  width: min( calc(100% - 32px), 500px);
  padding: 8px 12px;
  border: 1px solid #f4b2ac;
  border-radius: var(--radius);
  color: #7f2d27;
  background: var(--coral-soft);
  text-align: center;
  transform: translateX(-50%);
}

.login-view,
.app-shell {
  width: 100%;
  max-width: 540px;
  min-height: 100dvh;
  margin: 0 auto;
  background: var(--surface);
}

.login-view {
  display: grid;
  align-items: center;
  padding: 32px 24px;
}

.login-panel {
  width: 100%;
  max-width: 420px;
  margin: 0 auto;
}

.brand-icon {
  display: block;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.eyebrow,
.section-kicker {
  margin: 0;
  color: var(--blue);
  font-size: 13px;
  font-weight: 700;
}

.login-panel h1 {
  margin: 12px 0 6px;
  font-size: 30px;
  line-height: 1.25;
}

.supporting,
.page-heading p,
.recommendation-copy {
  color: var(--muted);
}

.login-form {
  display: grid;
  gap: 12px;
  margin-top: 32px;
}

.login-form label,
.analysis-form label,
.answer-form label,
.confirm-dialog label,
.field-label {
  font-size: 14px;
  font-weight: 700;
}

.password-field {
  display: grid;
  grid-template-columns: 1fr var(--tap);
  gap: 8px;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid #aeb9c9;
  border-radius: 6px;
  background: var(--surface);
}

input,
select {
  min-height: var(--tap);
  padding: 9px 12px;
}

textarea {
  min-height: 112px;
  padding: 12px;
  resize: vertical;
}

.primary-button,
.secondary-button,
.back-button {
  min-height: var(--tap);
  border-radius: 6px;
  font-weight: 700;
}

.primary-button {
  padding: 10px 18px;
  border: 1px solid var(--blue);
  color: var(--surface);
  background: var(--blue);
}

.primary-button:hover {
  background: #0958cc;
}

.secondary-button {
  padding: 10px 16px;
  border: 1px solid var(--blue);
  color: var(--blue);
  background: var(--surface);
}

.icon-button {
  display: inline-grid;
  width: var(--tap);
  min-width: var(--tap);
  height: var(--tap);
  place-items: center;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--blue);
  background: var(--surface);
}

.icon-button svg,
.section-icon svg,
.meta-row svg,
.save-status svg,
.bottom-nav svg,
.back-button svg {
  width: 20px;
  height: 20px;
  stroke-width: 2;
}

.form-error {
  margin: 0;
  color: #a12c24;
}

.app-shell {
  position: relative;
  padding-bottom: calc(64px + env(safe-area-inset-bottom));
  box-shadow: 0 0 0 1px var(--line);
}

.app-header {
  display: flex;
  min-height: 84px;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: max(16px, env(safe-area-inset-top)) 20px 12px;
  border-bottom: 1px solid var(--line);
}

.app-header h1 {
  margin: 2px 0 0;
  font-size: 24px;
  line-height: 1.25;
}

.view-container {
  min-height: calc(100dvh - 148px);
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.entry-band,
.single-column-view {
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
}

.section-heading h3,
.page-heading h2,
.dialog-heading h2 {
  margin: 2px 0 0;
  overflow-wrap: anywhere;
  line-height: 1.32;
}

.section-heading h3 {
  font-size: 20px;
}

.section-icon {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border-radius: 6px;
}

.blue-icon {
  color: var(--blue);
  background: var(--blue-soft);
}

.coral-icon {
  color: var(--coral);
  background: var(--coral-soft);
}

.recommendation-copy {
  min-height: 48px;
  margin: 12px 0;
}

.meta-row,
.action-row,
.input-tools,
.tool-group,
.answer-actions,
.with-action,
.dialog-heading {
  display: flex;
  align-items: center;
}

.meta-row {
  min-height: 28px;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

.meta-row span {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.action-row {
  gap: 8px;
  margin-top: 12px;
}

.grow {
  flex: 1;
}

.input-band textarea {
  min-height: 78px;
  margin-top: 12px;
}

.input-tools {
  min-height: 52px;
  justify-content: space-between;
  gap: 8px;
  margin-top: 6px;
}

.tool-group {
  gap: 6px;
}

.material-fields {
  display: grid;
  gap: 8px;
  padding-top: 8px;
}

.page-heading {
  margin-bottom: 22px;
}

.page-heading h2 {
  font-size: 24px;
}

.page-heading p:last-child {
  margin: 8px 0 0;
}

.empty-panel,
.feedback-panel {
  padding: 18px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.full-button {
  width: 100%;
  margin-top: 18px;
}

.back-button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin: -6px 0 14px;
  padding: 4px 0;
  border: 0;
  color: var(--blue);
  background: transparent;
}

.analysis-form,
.question-list {
  display: grid;
  gap: 12px;
}

.analysis-row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.analysis-row span {
  color: var(--muted);
}

.route-list {
  display: grid;
  gap: 8px;
  margin: 8px 0 0;
  padding-left: 22px;
}

.route-list li {
  padding-left: 4px;
}

.stack-actions {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 8px;
  margin-top: 12px;
}

.question-item {
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.question-item label {
  display: block;
  margin-bottom: 8px;
  font-weight: 700;
}

.learning-view.active {
  position: relative;
  display: block;
  min-height: 100dvh;
  background: var(--surface);
}

.learning-header {
  position: sticky;
  z-index: 10;
  top: 0;
  display: grid;
  min-height: 68px;
  grid-template-columns: var(--tap) minmax(0, 1fr) auto;
  gap: 10px;
  align-items: center;
  padding: max(10px, env(safe-area-inset-top)) 14px 10px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.learning-progress {
  min-width: 0;
  font-size: 13px;
  font-weight: 700;
}

.progress-track {
  width: 100%;
  height: 5px;
  margin-top: 5px;
  overflow: hidden;
  border-radius: 3px;
  background: var(--line);
}

.progress-track span {
  display: block;
  width: 25%;
  height: 100%;
  background: var(--blue);
  transition: width 180ms ease;
}

.save-status {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--success);
  font-size: 12px;
  white-space: nowrap;
}

.learning-content {
  padding: 22px 20px 40px;
}

.learning-content h2 {
  margin: 4px 0 8px;
  font-size: 25px;
  line-height: 1.3;
}

.learning-prompt {
  margin: 0 0 20px;
  color: var(--muted);
}

.source-materials {
  display: grid;
  gap: 0;
  margin-bottom: 20px;
  border-top: 1px solid var(--line);
}

.source-block,
.viewpoint-block {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.source-block p,
.viewpoint-block p {
  margin: 8px 0 0;
}

.viewpoint-block {
  margin: 10px 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--canvas);
}

.source-tag {
  display: inline-block;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 700;
}

.source-tag.external {
  color: var(--blue);
  background: var(--blue-soft);
}

.source-tag.knowledge {
  color: var(--success);
  background: var(--success-soft);
}

.source-tag.viewpoint {
  color: #4d596c;
  background: #e8ebef;
}

.answer-form {
  display: grid;
  gap: 8px;
}

.answer-actions {
  justify-content: space-between;
}

.feedback-panel {
  margin-top: 18px;
  color: var(--ink);
}

.style-feedback {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 13px;
}

.style-feedback span {
  width: 100%;
}

.style-feedback button,
.tabs button,
.filter-row button {
  min-height: 36px;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--muted);
  background: var(--surface);
  font-size: 13px;
}

.style-feedback button:hover,
.tabs button.active,
.filter-row button.active {
  border-color: var(--blue);
  color: var(--blue);
  background: var(--blue-soft);
}

.tabs,
.filter-row {
  display: grid;
  gap: 6px;
  margin-bottom: 18px;
}

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

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

.filter-row button {
  min-width: 0;
  padding: 5px 2px;
  overflow-wrap: anywhere;
}

.with-action,
.dialog-heading {
  justify-content: space-between;
  gap: 12px;
}

.result-list {
  display: grid;
  gap: 0;
}

.result-item {
  display: grid;
  gap: 8px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.result-item:first-child {
  border-top: 1px solid var(--line);
}

.result-item h3,
.sync-preview h3 {
  margin: 0;
  overflow-wrap: anywhere;
  font-size: 17px;
}

.result-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  color: var(--muted);
  font-size: 13px;
}

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

.status-line.error {
  color: #a12c24;
}

.bottom-nav {
  position: fixed;
  z-index: 20;
  right: 0;
  bottom: 0;
  left: 0;
  display: grid;
  width: 100%;
  max-width: 540px;
  height: 64px;
  grid-template-columns: repeat(4, 1fr);
  margin: 0 auto;
  padding-bottom: env(safe-area-inset-bottom);
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.bottom-nav button {
  display: grid;
  min-width: 0;
  min-height: 64px;
  place-items: center;
  align-content: center;
  gap: 2px;
  padding: 4px;
  border: 0;
  color: var(--muted);
  background: var(--surface);
  font-size: 12px;
}

.bottom-nav button.active {
  color: var(--blue);
  box-shadow: inset 0 3px 0 var(--blue);
}

.bottom-nav button:focus-visible {
  outline-offset: -3px;
}

.confirm-dialog {
  width: min( calc(100% - 32px), 500px);
  max-height: calc(100dvh - 32px);
  padding: 20px;
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--surface);
}

.confirm-dialog::backdrop {
  background: rgb(24 34 52 / 55%);
}

.confirm-dialog form {
  display: grid;
  gap: 14px;
}

.sync-preview {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--canvas);
}

.sync-preview ul {
  margin: 8px 0;
  padding-left: 20px;
}

.sync-preview p {
  margin: 8px 0 0;
  color: var(--muted);
}

.toast {
  position: fixed;
  z-index: 50;
  right: 20px;
  bottom: 82px;
  left: 20px;
  width: min( calc(100% - 40px), 500px);
  margin: 0 auto;
  padding: 11px 14px;
  border-radius: var(--radius);
  color: var(--surface);
  background: var(--ink);
  text-align: center;
}

@media (max-width: 390px) {
  .app-header,
  .entry-band,
  .single-column-view,
  .learning-content {
    padding-right: 16px;
    padding-left: 16px;
  }

  .entry-band {
    padding-top: 14px;
    padding-bottom: 14px;
  }

  .app-header {
    min-height: 76px;
  }

  .app-header h1 {
    font-size: 22px;
  }

  .recommendation-copy {
    min-height: 0;
    margin: 8px 0;
  }

  .section-heading h3 {
    font-size: 18px;
  }

  .filter-row button {
    font-size: 12px;
  }
}

@media (min-width: 800px) {
  body {
    padding: 22px 0;
  }

  .login-view,
  .app-shell {
    min-height: calc(100dvh - 44px);
  }

  .bottom-nav {
    bottom: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}