/*
 界面样式：定义暖白主题、响应式布局、底部导航与通用组件。
 以 iPad 竖屏为优先，同时支持窄屏手机和桌面浏览器。
 不引用字体、图片或任何第三方资源。
*/

:root {
  --bg: #fdfbf7;
  --surface: #ffffff;
  --surface-soft: #f5f1e9;
  --surface-blue: #eef5ff;
  --question-bg: #edf5ff;
  --question-line: #c7dcf8;
  --question-ink: #173b68;
  --answer-bg: #fff5e6;
  --answer-line: #f0c56f;
  --answer-ink: #5b401d;
  --text: #243044;
  --text-soft: #697386;
  --text-faint: #9aa1ae;
  --line: #e9e3d9;
  --blue: #3b82f6;
  --blue-deep: #245fc2;
  --blue-pale: #dbeaff;
  --orange: #f59e0b;
  --orange-pale: #fff2d5;
  --teal: #168f87;
  --teal-pale: #e3f5f1;
  --shadow: 0 8px 26px rgba(39, 49, 66, 0.06);
  --radius-lg: 20px;
  --radius-md: 16px;
  --content-width: 780px;
  --safe-bottom: max(12px, env(safe-area-inset-bottom));
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

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

body {
  min-width: 320px;
  min-height: 100dvh;
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 18px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  font: inherit;
}

button,
.card-button {
  touch-action: manipulation;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(59, 130, 246, 0.35);
  outline-offset: 3px;
}

button:active,
.card-button:active {
  transform: translateY(1px) scale(0.99);
}

a.button:active,
.tab:active,
.back-link:active,
.quick-card:active,
.focus-item:active,
.text-button:active,
.file-button:active {
  transform: translateY(1px) scale(0.99);
}

.app {
  width: min(100%, 920px);
  min-height: 100dvh;
  margin: 0 auto;
}

.view {
  width: min(100%, var(--content-width));
  min-height: 100dvh;
  margin: 0 auto;
  padding:
    max(28px, env(safe-area-inset-top))
    22px
    calc(106px + var(--safe-bottom));
}

.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 30px;
}

.page-kicker {
  margin: 0 0 6px;
  color: var(--blue-deep);
  font-size: 15px;
  font-weight: 750;
  letter-spacing: 0.08em;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 8px;
  font-size: clamp(30px, 6vw, 36px);
  line-height: 1.28;
  letter-spacing: -0.03em;
}

h2 {
  margin-bottom: 16px;
  font-size: 23px;
  line-height: 1.35;
}

h3 {
  margin-bottom: 8px;
  font-size: 19px;
  line-height: 1.4;
}

.subtitle {
  margin: 0;
  color: var(--text-soft);
  font-size: 17px;
}

.book-switcher {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 14px;
  padding: 15px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.book-switcher__copy {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 1px;
}

.book-switcher__copy > span,
.book-switcher__control > span {
  color: var(--text-soft);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.04em;
}

.book-switcher__copy strong {
  overflow: hidden;
  font-size: 16px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.book-switcher__copy small {
  color: var(--text-faint);
  font-size: 12px;
}

.book-switcher__control {
  display: flex;
  flex-shrink: 0;
  flex-direction: column;
  gap: 4px;
}

.book-switcher__control select {
  min-width: 220px;
  min-height: 48px;
  padding: 7px 34px 7px 12px;
  border: 1px solid var(--line);
  border-radius: 11px;
  outline: none;
  color: var(--text);
  background: var(--surface-soft);
  font: inherit;
  font-size: 15px;
}

.book-switcher__control select:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.16);
}

.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 6vw, 42px);
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero::after {
  position: absolute;
  top: -62px;
  right: -54px;
  width: 190px;
  height: 190px;
  border-radius: 50%;
  background: var(--surface-blue);
  content: "";
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 560px;
  margin-right: auto;
  margin-left: auto;
  text-align: center;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 auto 20px;
  padding: 7px 12px;
  border-radius: 999px;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 15px;
  font-weight: 700;
}

.hero h1 {
  font-size: clamp(31px, 7vw, 42px);
}

.hero__lead {
  max-width: 47ch;
  margin: 0 auto 28px;
  color: var(--text-soft);
  font-size: 18px;
}

.hero .status-line {
  justify-content: center;
  text-align: center;
}

.button {
  display: inline-flex;
  min-height: 52px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 14px;
  cursor: pointer;
  font-weight: 750;
  line-height: 1.2;
  text-decoration: none;
  transition:
    background-color 160ms ease,
    border-color 160ms ease,
    transform 100ms ease;
}

.button--primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 8px 18px rgba(59, 130, 246, 0.22);
}

.button--primary:hover {
  background: var(--blue-deep);
}

.button--secondary {
  color: var(--text);
  border-color: var(--line);
  background: var(--surface);
}

.button--secondary:hover {
  border-color: #d8d0c3;
  background: var(--surface-soft);
}

.button--wide {
  width: 100%;
}

.status-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  margin-top: 20px;
  padding: 15px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: var(--text-soft);
  background: rgba(255, 255, 255, 0.64);
  font-size: 16px;
}

.status-line span + span::before {
  padding-right: 18px;
  color: #c0bbb2;
  content: "｜";
}

.section {
  margin-top: 30px;
}

.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.section-heading h2 {
  margin: 0;
}

.section-heading__note {
  color: var(--text-soft);
  font-size: 15px;
}

.notice {
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.notice strong {
  display: block;
  margin-bottom: 4px;
}

.notice p {
  margin-bottom: 0;
  color: var(--text-soft);
}

.tabbar {
  position: fixed;
  z-index: 20;
  right: 0;
  bottom: 0;
  left: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(72px, 1fr));
  width: min(100%, 600px);
  margin: 0 auto;
  padding: 9px 14px var(--safe-bottom);
  border-top: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  box-shadow: 0 -6px 22px rgba(35, 45, 60, 0.04);
  backdrop-filter: blur(14px);
}

.tab {
  display: flex;
  min-height: 58px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  border-radius: 13px;
  color: var(--text-soft);
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  transition:
    color 150ms ease,
    background-color 150ms ease;
}

.tab:hover {
  background: var(--surface-soft);
}

.tab.is-active {
  color: var(--blue-deep);
  background: var(--surface-blue);
}

.tab__icon {
  font-size: 22px;
  line-height: 1.15;
}

.toast {
  position: fixed;
  z-index: 50;
  right: 20px;
  bottom: calc(96px + var(--safe-bottom));
  left: 20px;
  width: max-content;
  max-width: calc(100% - 40px);
  margin: auto;
  padding: 11px 17px;
  border: 1px solid var(--line);
  border-radius: 12px;
  opacity: 0;
  color: var(--text);
  background: var(--surface);
  box-shadow: var(--shadow);
  pointer-events: none;
  font-size: 16px;
  transform: translateY(8px);
  transition:
    opacity 160ms ease,
    transform 160ms ease;
}

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

.empty-state {
  padding: 38px 22px;
  border: 1px dashed #dad3c6;
  border-radius: var(--radius-lg);
  text-align: center;
}

.empty-state__mark {
  display: grid;
  width: 62px;
  height: 62px;
  margin: 0 auto 15px;
  place-items: center;
  border-radius: 50%;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 28px;
}

.empty-state p {
  max-width: 38ch;
  margin-right: auto;
  margin-bottom: 20px;
  margin-left: auto;
  color: var(--text-soft);
}

.unit-list {
  display: grid;
  gap: 12px;
}

.unit-row {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) auto;
  min-height: 84px;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
  box-shadow: 0 3px 12px rgba(39, 49, 66, 0.025);
}

.unit-row__no {
  display: grid;
  width: 45px;
  height: 45px;
  place-items: center;
  border-radius: 13px;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 20px;
  font-weight: 800;
  white-space: nowrap;
}

.unit-row__title {
  margin: 0;
  font-size: 18px;
  font-weight: 750;
  line-height: 1.35;
}

.unit-row__meta {
  margin: 4px 0 0;
  color: var(--text-soft);
  font-size: 14px;
}

.pill {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  padding: 4px 10px;
  border-radius: 999px;
  color: var(--text-soft);
  background: var(--surface-soft);
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}

.pill--live {
  color: var(--blue-deep);
  background: var(--blue-pale);
}

.loading,
.error-page {
  display: grid;
  min-height: 68dvh;
  place-items: center;
  text-align: center;
}

.spinner {
  width: 30px;
  height: 30px;
  margin: 0 auto 16px;
  border: 3px solid var(--blue-pale);
  border-top-color: var(--blue);
  border-radius: 50%;
  animation: spin 800ms linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.muted {
  color: var(--text-soft);
}

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

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #151821;
    --surface: #202531;
    --surface-soft: #292f3c;
    --surface-blue: #1e2e46;
    --question-bg: #1b2b42;
    --question-line: #35577f;
    --question-ink: #e8f2ff;
    --answer-bg: #362d20;
    --answer-line: #76562c;
    --answer-ink: #fff2d7;
    --text: #eff2f7;
    --text-soft: #adb5c3;
    --text-faint: #7d8798;
    --line: #313847;
    --blue: #69a1ff;
    --blue-deep: #8bb8ff;
    --blue-pale: #253d5d;
    --orange: #ffbd54;
    --orange-pale: #4f3b1e;
    --teal: #68c9c1;
    --teal-pale: #1f4747;
    --shadow: 0 8px 26px rgba(0, 0, 0, 0.18);
  }

  .status-line {
    background: rgba(32, 37, 49, 0.68);
  }

  .tabbar {
    background: color-mix(in srgb, var(--surface) 94%, transparent);
  }
}

@media (max-width: 520px) {
  .view {
    padding-right: 16px;
    padding-left: 16px;
  }

  .hero {
    padding: 26px 22px;
  }

  .book-switcher {
    align-items: stretch;
    flex-direction: column;
    gap: 12px;
  }

  .book-switcher__control select {
    width: 100%;
    min-width: 0;
  }

  .status-line span + span::before {
    padding-right: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Navigation and browsing */
.back-link {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  gap: 7px;
  margin: -10px 0 18px;
  padding: 7px 2px;
  color: var(--text-soft);
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
}

.back-link:hover {
  color: var(--blue-deep);
}

.page-header--compact {
  margin-bottom: 22px;
}

.page-header--compact h1 {
  font-size: clamp(27px, 6vw, 33px);
}

.unit-row--link {
  color: inherit;
  text-decoration: none;
  transition:
    border-color 150ms ease,
    transform 120ms ease,
    box-shadow 150ms ease;
}

.unit-row--link:hover {
  border-color: #bfd5f7;
  box-shadow: var(--shadow);
}

.unit-row--link:active {
  transform: scale(0.993);
}

.unit-row--muted {
  opacity: 0.72;
}

.kp-list {
  display: grid;
  gap: 11px;
}

.kp-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  min-height: 94px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: inherit;
  background: var(--surface);
  text-decoration: none;
  transition:
    border-color 150ms ease,
    transform 120ms ease;
}

.kp-row:hover {
  border-color: #bfd5f7;
}

.kp-row:active {
  transform: scale(0.993);
}

.kp-row__main h3 {
  margin-bottom: 4px;
}

.kp-row__main p {
  margin-bottom: 0;
  color: var(--text-soft);
  font-size: 14px;
}

.kp-row__side {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
}

.kp-row__meta {
  color: var(--text-soft);
  font-size: 12px;
  white-space: nowrap;
}

.stars {
  color: var(--orange);
  font-size: 15px;
  font-weight: 750;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.detail-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin-top: 12px;
  color: var(--text-soft);
  font-size: 14px;
}

.objectives {
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.objectives h2 {
  margin-bottom: 8px;
  font-size: 17px;
}

.objectives ul {
  margin: 0;
  padding-left: 21px;
  color: var(--text-soft);
  font-size: 15px;
}

.browse-list {
  display: grid;
  gap: 12px;
}

.browse-card {
  display: flex;
  width: 100%;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: var(--text);
  background: var(--surface);
  box-shadow: 0 3px 12px rgba(39, 49, 66, 0.025);
  cursor: pointer;
  text-align: left;
}

.browse-card.is-flipped {
  border-color: var(--question-line);
  background: var(--surface);
}

.browse-card__tag {
  padding: 3px 9px;
  border-radius: 999px;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 12px;
  font-weight: 750;
}

.browse-card__front-block {
  display: flex;
  width: 100%;
  flex-direction: column;
  align-items: flex-start;
  gap: 9px;
  padding: 15px 16px;
  border: 1px solid var(--question-line);
  border-radius: 14px;
  background: var(--question-bg);
}

.browse-card__front {
  font-size: 19px;
  font-weight: 750;
  line-height: 1.52;
  color: var(--question-ink);
}

.browse-card__back {
  display: flex;
  flex-direction: column;
  gap: 7px;
  width: 100%;
  padding: 15px 16px 17px;
  border: 1px solid var(--answer-line);
  border-radius: 14px;
  color: var(--answer-ink);
  background: var(--answer-bg);
  font-size: 17px;
}

.browse-card__back strong {
  font-weight: 650;
  line-height: 1.65;
}

.browse-card__back > span:not(.section-label) {
  color: var(--text-soft);
  font-size: 14px;
}

.browse-card__back .unverified {
  color: var(--orange);
  font-weight: 700;
}

.browse-card__hint {
  color: var(--text-faint);
  font-size: 13px;
}

.section-label {
  display: inline-flex;
  min-height: 25px;
  align-items: center;
  padding: 2px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  line-height: 1.4;
}

.section-label--question {
  color: var(--blue-deep);
  background: var(--blue-pale);
}

.section-label--answer {
  color: var(--answer-ink);
  background: rgba(245, 158, 11, 0.16);
}

.choice-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.choice-preview__item {
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 9px;
  color: var(--text-soft);
  background: var(--surface-soft);
  font-size: 14px;
}

.practice-bar {
  position: sticky;
  z-index: 5;
  bottom: calc(78px + var(--safe-bottom));
  margin-top: 20px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

/* Daily cards */
.quick-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.quick-card {
  display: flex;
  min-height: 118px;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: inherit;
  background: var(--surface);
  text-decoration: none;
}

.quick-card > span {
  margin-bottom: 4px;
  color: var(--blue);
  font-size: 23px;
}

.quick-card strong {
  font-size: 17px;
}

.quick-card small {
  color: var(--text-soft);
  font-size: 13px;
}

.quick-card:hover {
  border-color: #bfd5f7;
}

.focus-list {
  overflow: hidden;
  border: 1px solid #f3d59e;
  border-radius: var(--radius-md);
  background: var(--orange-pale);
}

.focus-item {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 17px;
  border-bottom: 1px solid rgba(245, 158, 11, 0.22);
  color: inherit;
  text-decoration: none;
}

.focus-item:last-child {
  border-bottom: 0;
}

.focus-item > span:first-child {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 3px;
}

.focus-item strong {
  font-size: 16px;
}

.focus-item small {
  color: var(--text-soft);
  font-size: 12px;
}

.today-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--line);
}

.today-summary > div {
  display: flex;
  flex-direction: column;
  padding: 16px 18px;
  background: var(--surface);
}

.today-summary strong {
  margin-bottom: 2px;
  font-size: 18px;
}

.today-summary span {
  color: var(--text-soft);
  font-size: 13px;
}

/* Review session */
body[data-route="session"] .tabbar {
  display: none;
}

body[data-route="session"] .view {
  padding-bottom: max(24px, env(safe-area-inset-bottom));
}

.session-header {
  margin-bottom: 18px;
}

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

.session-header__top .page-kicker {
  margin-bottom: 2px;
}

.session-header__top strong {
  font-size: 16px;
}

.icon-button {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--text-soft);
  background: var(--surface);
  cursor: pointer;
  font-size: 20px;
}

.progress-track {
  overflow: hidden;
  height: 7px;
  border-radius: 999px;
  background: var(--surface-soft);
}

.progress-track span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--blue);
  transition: width 220ms ease;
}

.study-card {
  display: flex;
  width: 100%;
  min-height: min(56dvh, 510px);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: clamp(22px, 5vw, 38px);
  border: 1px solid var(--line);
  border-radius: 24px;
  color: var(--text);
  background: var(--surface);
  box-shadow: var(--shadow);
  cursor: pointer;
  text-align: center;
  transition:
    border-color 200ms ease,
    background-color 200ms ease;
}

.study-card.is-flipped {
  border-color: var(--question-line);
  background: var(--surface);
  cursor: default;
}

.study-card__meta {
  padding: 4px 10px;
  border-radius: 999px;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 12px;
  font-weight: 750;
}

.study-card__question-block {
  display: flex;
  width: 100%;
  max-width: 620px;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: clamp(22px, 4.5vw, 34px);
  border: 1px solid var(--question-line);
  border-radius: 18px;
  background: var(--question-bg);
}

.study-card__question {
  max-width: 22ch;
  font-size: clamp(27px, 5.6vw, 34px);
  font-weight: 760;
  line-height: 1.48;
  letter-spacing: -0.02em;
  color: var(--question-ink);
}

.study-card__tap,
.keyboard-tip {
  color: var(--text-faint);
  font-size: 14px;
}

.study-card__answer-block {
  display: flex;
  width: 100%;
  max-width: 620px;
  flex-direction: column;
  align-items: center;
  gap: 11px;
  padding: 18px 22px 20px;
  border: 1px solid var(--answer-line);
  border-radius: 18px;
  background: var(--answer-bg);
}

.study-card__answer {
  display: flex;
  max-width: 34ch;
  flex-direction: column;
  gap: 9px;
  color: var(--answer-ink);
  font-size: 20px;
  line-height: 1.6;
}

.study-card__answer > strong {
  color: var(--answer-ink);
}

.study-card__answer > span {
  color: var(--answer-ink);
  opacity: 0.78;
  font-size: 15px;
}

.study-card__answer > em {
  color: var(--answer-ink);
  font-size: 14px;
  font-style: normal;
  font-weight: 650;
  opacity: 0.82;
}

.study-choice-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.study-choice {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 11px;
  color: var(--text-soft);
  background: var(--surface);
  font-size: 16px;
}

.study-choice b {
  color: var(--blue-deep);
}

.rating-panel {
  padding-top: 18px;
  animation: rating-in 180ms ease both;
}

.rating-panel > p {
  margin-bottom: 10px;
  color: var(--text-soft);
  font-size: 14px;
  text-align: center;
}

.rating-panel--chosen {
  opacity: 0.58;
  pointer-events: none;
}

.rating-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.rating-button {
  position: relative;
  display: flex;
  min-height: 66px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 15px;
  color: var(--text);
  background: var(--surface);
  cursor: pointer;
}

.rating-button > span {
  font-size: 18px;
  line-height: 1;
}

.rating-button strong {
  font-size: 16px;
}

.rating-button small {
  position: absolute;
  top: 7px;
  right: 9px;
  color: var(--text-faint);
  font-size: 10px;
}

.rating-button--again {
  border-color: #f3d59e;
  background: var(--orange-pale);
}

.rating-button--good {
  border-color: #a8ddd6;
  background: var(--teal-pale);
}

.keyboard-tip {
  margin: 14px 0 0;
  text-align: center;
}

@keyframes rating-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.summary {
  max-width: 620px;
  margin: 3vh auto 0;
  text-align: center;
}

.summary__mark,
.pin-gate__mark {
  display: grid;
  width: 68px;
  height: 68px;
  margin: 0 auto 18px;
  place-items: center;
  border-radius: 50%;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 29px;
  font-weight: 750;
}

.summary__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 24px 0 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--line);
}

.summary__stats > div {
  display: flex;
  flex-direction: column;
  padding: 15px 8px;
  background: var(--surface);
}

.summary__stats strong {
  font-size: 25px;
}

.summary__stats span {
  color: var(--text-soft);
  font-size: 13px;
}

.streak-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
  text-align: left;
}

.streak-card span {
  color: var(--text-soft);
}

.streak-card strong {
  color: var(--orange);
  font-size: 22px;
}

.streak-card small {
  color: var(--text-faint);
  font-size: 12px;
}

.summary__again {
  margin-top: 24px;
  text-align: left;
}

.summary__again h2 {
  margin-bottom: 3px;
}

.review-again-item {
  display: flex;
  width: 100%;
  flex-direction: column;
  gap: 6px;
  margin-top: 8px;
  padding: 14px 16px;
  border: 1px solid #f3d59e;
  border-radius: 13px;
  color: var(--text);
  background: var(--orange-pale);
  cursor: pointer;
  font-size: 16px;
  text-align: left;
}

.review-again-item__answer {
  color: var(--text-soft);
}

.summary__actions {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

/* Parent dashboard */
.pin-gate {
  max-width: 500px;
  margin: 5vh auto 0;
  padding: 32px 24px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
  text-align: center;
}

.pin-gate h1 {
  font-size: 30px;
}

.pin-form {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.pin-input {
  width: 100%;
  min-height: 58px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: 13px;
  outline: none;
  color: var(--text);
  background: var(--surface-soft);
  font-size: 23px;
  font-weight: 700;
  letter-spacing: 0.3em;
  text-align: center;
}

.pin-input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.16);
}

.form-error {
  min-height: 26px;
  margin: 0;
  color: var(--orange);
  font-size: 14px;
}

.privacy-note {
  margin: 17px 0 0;
  color: var(--text-faint);
  font-size: 13px;
}

.dashboard-section {
  margin-top: 28px;
}

.accuracy-list,
.weak-list,
.settings-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.accuracy-row,
.weak-row {
  display: flex;
  min-height: 70px;
  align-items: center;
  justify-content: space-between;
  gap: 15px;
  padding: 14px 17px;
  border-bottom: 1px solid var(--line);
}

.accuracy-row:last-child,
.weak-row:last-child {
  border-bottom: 0;
}

.accuracy-row > div:first-child,
.weak-row > div:first-child {
  display: flex;
  min-width: 0;
  flex-direction: column;
}

.accuracy-row strong,
.weak-row strong {
  font-size: 16px;
}

.accuracy-row small,
.weak-row small {
  color: var(--text-soft);
  font-size: 12px;
}

.accuracy-value {
  display: flex;
  width: 112px;
  flex-direction: column;
  align-items: flex-end;
  gap: 5px;
  color: var(--blue-deep);
  font-size: 17px;
  font-weight: 750;
}

.accuracy-bar {
  overflow: hidden;
  width: 100%;
  height: 5px;
  border-radius: 99px;
  background: var(--surface-soft);
}

.accuracy-bar i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--blue);
}

.week-chart {
  display: grid;
  height: 145px;
  grid-template-columns: repeat(7, 1fr);
  gap: 8px;
  padding: 18px 14px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.day-bar {
  display: flex;
  min-width: 0;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.day-bar__track {
  display: flex;
  width: min(100%, 28px);
  flex: 1;
  align-items: flex-end;
  overflow: hidden;
  border-radius: 8px;
  background: var(--surface-soft);
}

.day-bar__track i {
  display: block;
  width: 100%;
  border-radius: inherit;
  background: #d8d3ca;
}

.day-bar__track i.is-studied {
  background: var(--blue);
}

.day-bar small {
  color: var(--text-faint);
  font-size: 11px;
}

.setting-range,
.setting-toggle,
.setting-select {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px 17px;
  border-bottom: 1px solid var(--line);
}

.setting-range:last-child,
.setting-toggle:last-child,
.setting-select:last-child {
  border-bottom: 0;
}

.setting-range > span,
.setting-toggle > span,
.setting-select > span {
  display: flex;
  flex-direction: column;
}

.setting-range strong,
.setting-toggle strong,
.setting-select strong {
  font-size: 16px;
}

.setting-range small,
.setting-toggle small,
.setting-select small {
  color: var(--text-soft);
  font-size: 12px;
}

.setting-range input {
  width: 150px;
  accent-color: var(--blue);
}

.setting-toggle input {
  width: 24px;
  height: 24px;
  accent-color: var(--blue);
}

.setting-select select {
  min-height: 44px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--text);
  background: var(--surface-soft);
  font: inherit;
  font-size: 15px;
}

.data-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.file-button {
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

.file-button input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.button--danger {
  color: var(--orange);
}

.notice--small {
  margin-top: 12px;
}

.notice--small strong {
  font-size: 15px;
}

.notice--small p {
  font-size: 13px;
}

.text-button {
  min-height: 48px;
  margin-top: 12px;
  padding: 8px 0;
  border: 0;
  color: var(--text-soft);
  background: transparent;
  cursor: pointer;
  font-size: 14px;
  text-decoration: underline;
  text-decoration-color: var(--line);
  text-underline-offset: 4px;
}

/* Exit confirmation */
.confirm-overlay {
  position: fixed;
  z-index: 110;
  inset: 0;
  display: grid;
  padding: 20px;
  place-items: center;
  background: rgba(29, 38, 53, 0.46);
  backdrop-filter: blur(7px);
}

.confirm-panel {
  width: min(100%, 420px);
  padding: 28px 24px 24px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: 0 20px 60px rgba(24, 32, 45, 0.24);
  text-align: center;
}

.confirm-panel__mark {
  display: grid;
  width: 54px;
  height: 54px;
  margin: 0 auto 14px;
  place-items: center;
  border-radius: 50%;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 24px;
  font-weight: 800;
}

.confirm-panel__mark.pwa-mark {
  color: var(--teal);
  background: var(--teal-pale);
}

.confirm-panel h2 {
  margin-bottom: 8px;
  font-size: 24px;
}

.confirm-panel p {
  margin-bottom: 22px;
  color: var(--text-soft);
  font-size: 16px;
}

.confirm-panel__actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.confirm-panel__actions--single {
  grid-template-columns: 1fr;
}

/* First-use guide */
.onboarding {
  position: fixed;
  z-index: 100;
  inset: 0;
  display: grid;
  padding: max(20px, env(safe-area-inset-top)) 20px max(20px, env(safe-area-inset-bottom));
  place-items: center;
  background: rgba(29, 38, 53, 0.42);
  backdrop-filter: blur(8px);
}

.onboarding__panel {
  position: relative;
  width: min(100%, 450px);
  padding: 34px 26px 26px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 20px 60px rgba(24, 32, 45, 0.22);
  text-align: center;
}

.onboarding__skip {
  position: absolute;
  top: 12px;
  right: 14px;
  min-width: 48px;
  min-height: 48px;
  border: 0;
  color: var(--text-soft);
  background: transparent;
  cursor: pointer;
}

.onboarding__mark {
  display: grid;
  width: 70px;
  height: 70px;
  margin: 0 auto 18px;
  place-items: center;
  border-radius: 22px;
  color: var(--blue-deep);
  background: var(--blue-pale);
  font-size: 26px;
  font-weight: 800;
}

.onboarding__dots {
  display: flex;
  justify-content: center;
  gap: 7px;
  margin: 22px 0 18px;
}

.onboarding__dots span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--line);
}

.onboarding__dots span.is-active {
  width: 21px;
  border-radius: 99px;
  background: var(--blue);
}

[data-theme="dark"] {
  --bg: #151821;
  --surface: #202531;
  --surface-soft: #292f3c;
  --surface-blue: #1e2e46;
  --question-bg: #1b2b42;
  --question-line: #35577f;
  --question-ink: #e8f2ff;
  --answer-bg: #362d20;
  --answer-line: #76562c;
  --answer-ink: #fff2d7;
  --text: #eff2f7;
  --text-soft: #adb5c3;
  --text-faint: #7d8798;
  --line: #313847;
  --blue: #69a1ff;
  --blue-deep: #8bb8ff;
  --blue-pale: #253d5d;
  --orange: #ffbd54;
  --orange-pale: #4f3b1e;
  --teal: #68c9c1;
  --teal-pale: #1f4747;
  --shadow: 0 8px 26px rgba(0, 0, 0, 0.18);
}

@media (max-width: 520px) {
  .kp-row {
    grid-template-columns: 1fr;
  }

  .kp-row__side {
    align-items: flex-start;
    flex-direction: row;
  }

  .study-card {
    min-height: 54dvh;
  }

  .rating-grid {
    gap: 7px;
  }

  .rating-button strong {
    font-size: 14px;
  }

  .data-actions {
    grid-template-columns: 1fr;
  }

  .streak-card {
    align-items: flex-start;
    flex-direction: column;
  }

  .setting-range {
    align-items: flex-start;
    flex-direction: column;
  }

  .setting-range input {
    width: 100%;
  }
}