@layer reset, tokens, base, layout, components, utilities, responsive;

@layer reset {
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }

  html {
    color-scheme: light;
    scroll-behavior: smooth;
  }

  body,
  h1,
  h2,
  h3,
  h4,
  p,
  figure,
  blockquote,
  dl,
  dd {
    margin: 0;
  }

  ul,
  ol {
    margin: 0;
    padding: 0;
  }

  button,
  input,
  select,
  textarea {
    font: inherit;
  }

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

  img,
  svg {
    display: block;
    max-width: 100%;
  }
}

@layer tokens {
  :root {
    --paper-50: #fbf8f1;
    --paper-100: #f4efe5;
    --paper-200: #e7ddce;
    --paper-300: #d7c9b5;
    --ink-950: #101d2c;
    --ink-900: #15283f;
    --ink-800: #213953;
    --ink-700: #385069;
    --ink-500: #596b7d;
    --ink-300: #aeb8c2;
    --vermillion-700: #a52f28;
    --vermillion-600: #c33e31;
    --vermillion-500: #d84b38;
    --vermillion-300: #f08a76;
    --vermillion-100: #f6dcd3;
    --moss-700: #42624f;
    --moss-100: #dfe9df;
    --gold-700: #8a641d;
    --gold-100: #f4e7bd;
    --white: #fffdf8;
    --danger: #a62c2c;
    --success: #386349;
    --shadow-soft: 0 18px 50px rgb(21 40 63 / 9%);
    --shadow-lift: 0 20px 45px rgb(21 40 63 / 16%);
    --radius-xs: 5px;
    --radius-sm: 9px;
    --radius-md: 14px;
    --radius-lg: 22px;
    --font-ui: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP Variable", sans-serif;
    --font-jp-sans: "Noto Sans JP Variable", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", sans-serif;
    --font-display: Iowan Old Style, "Palatino Linotype", "Yu Mincho", "Hiragino Mincho ProN", "Noto Sans JP Variable", serif;
    --step--1: clamp(0.78rem, 0.75rem + 0.14vw, 0.88rem);
    --step-0: clamp(0.96rem, 0.9rem + 0.23vw, 1.08rem);
    --step-1: clamp(1.18rem, 1.04rem + 0.53vw, 1.44rem);
    --step-2: clamp(1.45rem, 1.2rem + 0.95vw, 1.95rem);
    --step-3: clamp(1.85rem, 1.4rem + 1.7vw, 2.8rem);
    --step-4: clamp(2.4rem, 1.62rem + 3.1vw, 4.2rem);
    --space-1: 0.35rem;
    --space-2: 0.65rem;
    --space-3: 1rem;
    --space-4: 1.4rem;
    --space-5: 2rem;
    --space-6: 3rem;
    --space-7: 4.5rem;
    --content-max: 1180px;
  }
}

@layer base {
  body {
    min-width: 320px;
    min-height: 100vh;
    background:
      linear-gradient(90deg, rgb(21 40 63 / 2%) 1px, transparent 1px) 0 0 / 48px 48px,
      linear-gradient(rgb(21 40 63 / 2%) 1px, transparent 1px) 0 0 / 48px 48px,
      var(--paper-100);
    color: var(--ink-950);
    font-family: var(--font-ui);
    font-size: var(--step-0);
    line-height: 1.65;
    text-rendering: optimizeLegibility;
  }

  h1,
  h2,
  h3,
  h4 {
    color: var(--ink-950);
    font-family: var(--font-display);
    font-weight: 600;
    letter-spacing: -0.025em;
    line-height: 1.08;
    text-wrap: balance;
  }

  h1 {
    font-size: var(--step-4);
  }

  h2 {
    font-size: var(--step-3);
  }

  h3 {
    font-size: var(--step-2);
  }

  h4 {
    font-size: var(--step-1);
  }

  p {
    max-width: 68ch;
  }

  a {
    color: inherit;
  }

  button {
    border: 0;
    cursor: pointer;
  }

  button:disabled,
  input:disabled {
    cursor: not-allowed;
    opacity: 0.55;
  }

  :focus-visible {
    outline: 3px solid var(--vermillion-500);
    outline-offset: 3px;
  }

  ::selection {
    background: var(--vermillion-100);
    color: var(--ink-950);
  }
}

@layer layout {
  .app-shell {
    min-height: 100vh;
  }

  .sidebar {
    position: fixed;
    z-index: 20;
    inset: 0 auto 0 0;
    display: flex;
    width: 252px;
    flex-direction: column;
    border-right: 1px solid rgb(244 239 229 / 18%);
    background: var(--ink-900);
    color: var(--paper-100);
    padding: 28px 22px 24px;
  }

  .sidebar::after {
    position: absolute;
    top: 132px;
    bottom: 160px;
    left: 42px;
    width: 2px;
    background: linear-gradient(var(--vermillion-500), rgb(216 75 56 / 12%));
    content: "";
  }

  .main-stage {
    min-height: 100vh;
    margin-left: 252px;
    padding: 32px clamp(24px, 5vw, 80px) 72px;
  }

  .content-frame {
    width: min(100%, var(--content-max));
    margin-inline: auto;
  }

  .view-header {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: var(--space-4);
    margin-block: var(--space-4) var(--space-6);
  }

  .view-header > div:first-child {
    min-width: 0;
  }

  .view-header p:not(.eyebrow) {
    margin-top: var(--space-2);
    color: var(--ink-700);
  }

  .section-stack {
    display: grid;
    gap: var(--space-6);
  }

  .dashboard-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.6fr) minmax(280px, 0.75fr);
    align-items: stretch;
    gap: var(--space-4);
  }

  .split-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4);
  }

  .three-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-3);
  }

  .lesson-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 250px;
    align-items: start;
    gap: var(--space-4);
  }

  .lesson-aside {
    position: sticky;
    top: 24px;
    display: grid;
    gap: var(--space-3);
  }
}

@layer components {
  .skip-link {
    position: fixed;
    z-index: 1000;
    top: 12px;
    left: 12px;
    translate: 0 -180%;
    background: var(--white);
    color: var(--ink-950);
    padding: 10px 14px;
    text-decoration: none;
  }

  .skip-link:focus {
    translate: 0;
  }

  .boot-screen,
  .noscript-message {
    display: grid;
    min-height: 100vh;
    place-content: center;
    gap: var(--space-2);
    padding: var(--space-5);
    text-align: center;
  }

  .brand {
    display: grid;
    grid-template-columns: 42px 1fr;
    align-items: center;
    gap: 12px;
    color: var(--paper-50);
    text-decoration: none;
  }

  .brand__mark {
    display: grid;
    width: 42px;
    aspect-ratio: 1;
    place-items: center;
    border: 1px solid rgb(244 239 229 / 30%);
    color: var(--paper-50);
    font-family: var(--font-display);
    font-size: 1.55rem;
  }

  .brand__name {
    display: block;
    font-family: var(--font-display);
    font-size: 1.15rem;
    letter-spacing: 0.05em;
  }

  .brand__tagline {
    display: block;
    color: var(--ink-300);
    font-size: 0.7rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
  }

  .primary-nav {
    display: grid;
    gap: 4px;
    margin-top: 52px;
  }

  .nav-link {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 40px 1fr;
    align-items: center;
    min-height: 48px;
    border: 1px solid transparent;
    background: transparent;
    color: var(--ink-300);
    padding: 7px 10px 7px 0;
    text-align: left;
  }

  .nav-link__icon {
    display: grid;
    width: 40px;
    place-items: center;
    font-family: var(--font-display);
    font-size: 0.85rem;
  }

  .nav-link:hover {
    color: var(--paper-50);
  }

  .nav-link[aria-current="page"] {
    border-color: rgb(244 239 229 / 14%);
    background: rgb(244 239 229 / 8%);
    color: var(--paper-50);
  }

  .nav-link[aria-current="page"]::before {
    position: absolute;
    left: 19px;
    width: 8px;
    height: 8px;
    border: 2px solid var(--ink-900);
    border-radius: 50%;
    background: var(--vermillion-500);
    content: "";
  }

  .sidebar-footer {
    display: grid;
    gap: var(--space-3);
    margin-top: auto;
  }

  .mini-progress {
    display: grid;
    gap: 7px;
    border-top: 1px solid rgb(244 239 229 / 18%);
    padding-top: 16px;
  }

  .mini-progress__label {
    display: flex;
    justify-content: space-between;
    color: var(--ink-300);
    font-size: var(--step--1);
  }

  .progress-track {
    overflow: hidden;
    height: 5px;
    background: rgb(244 239 229 / 14%);
  }

  .progress-track > span {
    display: block;
    width: var(--progress, 0%);
    height: 100%;
    background: var(--vermillion-500);
    transition: width 420ms ease;
  }

  .mobile-header,
  .mobile-nav {
    display: none;
  }

  .eyebrow {
    color: var(--vermillion-700);
    font-size: var(--step--1);
    font-weight: 760;
    letter-spacing: 0.12em;
    text-transform: uppercase;
  }

  .title-jp {
    font-family: var(--font-jp-sans);
    font-weight: 600;
    letter-spacing: 0;
  }

  .lead {
    color: var(--ink-700);
    font-size: var(--step-1);
    line-height: 1.5;
  }

  .muted {
    color: var(--ink-500);
  }

  .surface {
    border: 1px solid var(--paper-300);
    background: rgb(255 253 248 / 88%);
    box-shadow: var(--shadow-soft);
  }

  .today-card {
    position: relative;
    display: grid;
    min-height: 390px;
    overflow: hidden;
    grid-template-rows: auto 1fr auto;
    border-top: 5px solid var(--ink-900);
    padding: clamp(24px, 5vw, 54px);
  }

  .today-card::after {
    position: absolute;
    top: 36px;
    right: -52px;
    width: 180px;
    height: 180px;
    border: 1px solid var(--paper-300);
    border-radius: 50%;
    box-shadow: 0 0 0 22px rgb(215 201 181 / 18%), 0 0 0 44px rgb(215 201 181 / 9%);
    content: "";
  }

  .today-card__body {
    position: relative;
    z-index: 1;
    align-self: center;
    max-width: 650px;
    padding-block: var(--space-5);
  }

  .today-card h2 {
    max-width: 13ch;
  }

  .today-card__body p {
    margin-top: var(--space-3);
    color: var(--ink-700);
  }

  .today-card__footer {
    position: relative;
    z-index: 1;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    border-top: 1px solid var(--paper-300);
    padding-top: var(--space-4);
  }

  .meta-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
    color: var(--ink-700);
    font-size: var(--step--1);
  }

  .meta-row span {
    display: inline-flex;
    align-items: center;
    gap: 6px;
  }

  .side-card {
    display: grid;
    align-content: start;
    gap: var(--space-4);
    border-left: 4px solid var(--vermillion-500);
    padding: 28px;
  }

  .side-card__kana {
    color: var(--ink-900);
    font-family: var(--font-jp-sans);
    font-size: clamp(3.8rem, 5vw, 6rem);
    font-weight: 500;
    letter-spacing: -0.12em;
    line-height: 1;
    white-space: nowrap;
  }

  .side-card dl {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 8px 12px;
    border-top: 1px solid var(--paper-300);
    padding-top: var(--space-3);
    font-size: var(--step--1);
  }

  .side-card dd {
    font-weight: 750;
  }

  .button {
    display: inline-flex;
    min-height: 46px;
    align-items: center;
    justify-content: center;
    gap: 9px;
    border: 1px solid transparent;
    border-radius: var(--radius-xs);
    padding: 10px 17px;
    font-weight: 720;
    line-height: 1.2;
    text-decoration: none;
    transition: translate 160ms ease, box-shadow 160ms ease, background 160ms ease;
  }

  .button:hover:not(:disabled) {
    translate: 0 -2px;
  }

  .button--primary {
    background: var(--vermillion-600);
    color: var(--white);
    box-shadow: 0 8px 18px rgb(195 62 49 / 20%);
  }

  .button--primary:hover:not(:disabled) {
    background: var(--vermillion-700);
    box-shadow: 0 12px 23px rgb(195 62 49 / 27%);
  }

  .button--ink {
    background: var(--ink-900);
    color: var(--paper-50);
  }

  .button--quiet {
    border-color: var(--paper-300);
    background: transparent;
    color: var(--ink-900);
  }

  .button--quiet:hover:not(:disabled) {
    background: var(--paper-200);
  }

  .button--text {
    min-height: 40px;
    border-bottom: 1px solid currentColor;
    border-radius: 0;
    background: transparent;
    color: var(--ink-900);
    padding-inline: 0;
  }

  .button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
  }

  .icon-button {
    display: inline-grid;
    width: 46px;
    min-width: 46px;
    height: 46px;
    place-items: center;
    border: 1px solid var(--paper-300);
    border-radius: 50%;
    background: var(--white);
    color: var(--ink-900);
    font-weight: 800;
  }

  .icon-button:hover {
    border-color: var(--vermillion-500);
    color: var(--vermillion-700);
  }

  .section-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding-bottom: var(--space-3);
  }

  .section-heading h2,
  .section-heading h3 {
    max-width: 20ch;
  }

  .metric-strip {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    border-block: 1px solid var(--paper-300);
  }

  .metric {
    padding: 18px 16px;
  }

  .metric + .metric {
    border-left: 1px solid var(--paper-300);
  }

  .metric__value {
    display: block;
    font-family: var(--font-display);
    font-size: var(--step-2);
    line-height: 1;
  }

  .metric__label {
    display: block;
    margin-top: 7px;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .thread-list {
    position: relative;
    display: grid;
    gap: 0;
    list-style: none;
  }

  .thread-list::before {
    position: absolute;
    top: 28px;
    bottom: 28px;
    left: 23px;
    width: 2px;
    background: var(--paper-300);
    content: "";
  }

  .thread-item {
    position: relative;
    display: grid;
    grid-template-columns: 48px minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-3);
    min-height: 84px;
    border-bottom: 1px solid var(--paper-300);
    padding: 12px 0;
  }

  .thread-item__dot {
    z-index: 1;
    display: grid;
    width: 46px;
    height: 46px;
    place-items: center;
    border: 2px solid var(--paper-300);
    border-radius: 50%;
    background: var(--paper-100);
    color: var(--ink-700);
    font-size: var(--step--1);
    font-weight: 800;
  }

  .thread-item[data-state="active"] .thread-item__dot,
  .thread-item[data-state="complete"] .thread-item__dot {
    border-color: var(--vermillion-500);
    background: var(--vermillion-500);
    color: var(--white);
  }

  .thread-item[data-state="locked"] {
    color: var(--ink-500);
  }

  .thread-item__copy h3 {
    font-family: var(--font-ui);
    font-size: var(--step-1);
    letter-spacing: -0.01em;
  }

  .thread-item__copy p {
    margin-top: 2px;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .status-label {
    color: var(--ink-500);
    font-size: var(--step--1);
    font-weight: 720;
  }

  .status-label--ready {
    color: var(--vermillion-700);
  }

  .level-band {
    display: grid;
    grid-template-columns: 180px minmax(0, 1fr);
    gap: var(--space-5);
    border-top: 1px solid var(--paper-300);
    padding-block: var(--space-5);
  }

  .journey-overview {
    border-top: 5px solid var(--ink-900);
    padding: clamp(24px, 4vw, 42px);
  }

  .journey-overview__score {
    color: var(--vermillion-700);
    font-family: var(--font-display);
    font-size: var(--step-3);
    line-height: 1;
  }

  .journey-overview .progress-track,
  .side-card .progress-track,
  .level-band .progress-track {
    background: var(--paper-300);
  }

  .milestone-list {
    display: grid;
    gap: var(--space-4);
  }

  .milestone {
    display: grid;
    grid-template-columns: minmax(230px, 0.7fr) minmax(0, 1.3fr);
    gap: var(--space-5);
    border: 1px solid var(--paper-300);
    border-left: 5px solid var(--paper-300);
    background: rgb(255 253 248 / 72%);
    padding: clamp(20px, 3.5vw, 34px);
  }

  .milestone[data-state="active"] {
    border-left-color: var(--vermillion-500);
    background: var(--white);
    box-shadow: var(--shadow-soft);
  }

  .milestone[data-state="complete"] {
    border-left-color: var(--success);
  }

  .milestone[data-state="locked"] .milestone__head {
    opacity: 0.68;
  }

  .milestone__head {
    display: grid;
    grid-template-columns: 54px minmax(0, 1fr);
    align-content: start;
    gap: var(--space-3);
  }

  .milestone__head h3 {
    font-size: var(--step-2);
  }

  .milestone__head p:last-child {
    margin-top: 8px;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .milestone__number {
    display: grid;
    width: 48px;
    height: 48px;
    place-items: center;
    border: 1px solid var(--paper-300);
    border-radius: 50%;
    background: var(--paper-100);
    color: var(--ink-900);
    font-family: var(--font-display);
    font-size: var(--step-1);
    font-weight: 700;
  }

  .milestone[data-state="active"] .milestone__number {
    border-color: var(--vermillion-500);
    background: var(--vermillion-500);
    color: var(--white);
  }

  .milestone[data-state="complete"] .milestone__number {
    border-color: var(--success);
    background: var(--success);
    color: var(--white);
  }

  .curriculum-details {
    overflow: clip;
  }

  .curriculum-details > summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    cursor: pointer;
    list-style: none;
    padding: 22px clamp(20px, 4vw, 38px);
  }

  .curriculum-details > summary::-webkit-details-marker {
    display: none;
  }

  .curriculum-details > summary span:first-child {
    display: grid;
  }

  .curriculum-details > summary small {
    color: var(--vermillion-700);
    font-size: var(--step--1);
    font-weight: 760;
    letter-spacing: 0.08em;
    text-transform: uppercase;
  }

  .curriculum-details > summary strong {
    font-family: var(--font-display);
    font-size: var(--step-1);
  }

  .curriculum-details > summary span:last-child {
    color: var(--vermillion-700);
    font-size: var(--step-2);
    transition: transform 180ms ease;
  }

  .curriculum-details[open] > summary span:last-child {
    transform: rotate(45deg);
  }

  .curriculum-details__body {
    border-top: 1px solid var(--paper-300);
    padding: 4px clamp(20px, 4vw, 38px) 28px;
  }

  .level-band__label {
    position: sticky;
    top: 24px;
    align-self: start;
  }

  .level-band__label strong {
    display: block;
    font-family: var(--font-display);
    font-size: var(--step-2);
  }

  .level-band__label span {
    color: var(--ink-500);
    font-size: var(--step--1);
  }

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

  .module-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding: 15px 0;
  }

  .module-row h3 {
    font-family: var(--font-ui);
    font-size: var(--step-0);
    letter-spacing: 0;
  }

  .module-row p {
    margin-top: 3px;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .module-row__meta {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--ink-500);
    font-size: var(--step--1);
    white-space: nowrap;
  }

  .lock-label {
    max-width: 220px;
    color: var(--ink-500);
    line-height: 1.35;
    text-align: right;
    white-space: normal;
  }

  .onboarding {
    display: grid;
    min-height: 100vh;
    grid-template-columns: minmax(300px, 0.85fr) minmax(0, 1.5fr);
    background: var(--paper-100);
  }

  .onboarding__story {
    position: relative;
    display: flex;
    overflow: hidden;
    flex-direction: column;
    justify-content: space-between;
    background: var(--ink-900);
    color: var(--paper-100);
    padding: clamp(30px, 6vw, 80px);
  }

  .onboarding__story::after {
    position: absolute;
    right: -80px;
    bottom: -80px;
    width: 360px;
    height: 360px;
    border: 2px solid rgb(244 239 229 / 12%);
    border-radius: 50%;
    box-shadow: 0 0 0 48px rgb(244 239 229 / 4%), 0 0 0 96px rgb(244 239 229 / 3%);
    content: "";
  }

  .onboarding__story h1 {
    max-width: 9ch;
    color: var(--paper-50);
  }

  .onboarding__story .eyebrow {
    color: var(--vermillion-300);
  }

  .onboarding__story p {
    position: relative;
    z-index: 1;
    color: var(--ink-300);
  }

  .onboarding__form {
    display: grid;
    min-width: 0;
    place-items: center;
    padding: clamp(24px, 6vw, 80px);
  }

  .form-sheet {
    width: min(100%, 760px);
  }

  .form-sheet__head {
    margin-bottom: var(--space-5);
  }

  .form-sheet__head p {
    margin-top: var(--space-2);
    color: var(--ink-700);
  }

  .step-indicator {
    display: flex;
    gap: 7px;
    margin-bottom: var(--space-4);
  }

  .step-indicator span {
    width: 44px;
    height: 3px;
    background: var(--paper-300);
  }

  .step-indicator span[data-active="true"] {
    background: var(--vermillion-500);
  }

  .choice-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-block: var(--space-4);
  }

  .choice-card {
    display: grid;
    min-height: 126px;
    align-content: space-between;
    gap: 16px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-sm);
    background: var(--white);
    color: var(--ink-950);
    padding: 18px;
    text-align: left;
  }

  .choice-card:hover {
    border-color: var(--vermillion-500);
  }

  .choice-card[aria-pressed="true"] {
    border-color: var(--vermillion-600);
    box-shadow: inset 0 0 0 2px var(--vermillion-600);
  }

  .choice-card__jp {
    color: var(--ink-700);
    font-family: var(--font-jp-sans);
    font-size: 1.6rem;
  }

  .choice-card strong {
    display: block;
  }

  .choice-card small {
    display: block;
    margin-top: 3px;
    color: var(--ink-500);
  }

  .form-field {
    display: grid;
    gap: 7px;
    margin-block: var(--space-3);
  }

  .form-field label,
  .form-legend {
    font-weight: 730;
  }

  .form-field input,
  .form-field select,
  .form-field textarea {
    width: 100%;
    min-height: 48px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-950);
    padding: 11px 13px;
  }

  .form-field textarea {
    min-height: 120px;
    resize: vertical;
  }

  .form-actions {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    border-top: 1px solid var(--paper-300);
    margin-top: var(--space-5);
    padding-top: var(--space-4);
  }

  .toggle-row {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding: 15px 0;
  }

  .toggle-row strong {
    display: block;
  }

  .toggle-row small {
    display: block;
    color: var(--ink-500);
  }

  .switch {
    position: relative;
    width: 48px;
    height: 28px;
  }

  .switch input {
    position: absolute;
    opacity: 0;
  }

  .switch span {
    position: absolute;
    inset: 0;
    border: 1px solid var(--ink-300);
    border-radius: 20px;
    background: var(--paper-200);
    transition: background 160ms ease;
  }

  .switch span::after {
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--white);
    box-shadow: 0 1px 3px rgb(0 0 0 / 18%);
    content: "";
    transition: translate 160ms ease;
  }

  .switch input:checked + span {
    border-color: var(--moss-700);
    background: var(--moss-700);
  }

  .switch input:checked + span::after {
    translate: 20px 0;
  }

  .lesson-progress {
    display: grid;
    grid-template-columns: auto minmax(80px, 1fr) auto;
    align-items: center;
    gap: 12px;
    margin-bottom: var(--space-4);
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .lesson-sheet {
    min-height: 650px;
    border-top: 5px solid var(--ink-900);
    padding: clamp(24px, 5vw, 58px);
  }

  .lesson-sheet__header {
    display: grid;
    gap: var(--space-2);
    border-bottom: 1px solid var(--paper-300);
    padding-bottom: var(--space-4);
  }

  .lesson-sheet__body {
    padding-block: var(--space-5);
  }

  .lesson-sheet__body > * + * {
    margin-top: var(--space-4);
  }

  .lesson-sheet__footer {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    border-top: 1px solid var(--paper-300);
    padding-top: var(--space-4);
  }

  .lesson-index {
    display: grid;
    gap: 4px;
    list-style: none;
  }

  .lesson-index li {
    display: grid;
    grid-template-columns: 26px 1fr;
    align-items: center;
    gap: 8px;
    min-height: 34px;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .lesson-index li::before {
    display: grid;
    width: 22px;
    height: 22px;
    place-items: center;
    border: 1px solid var(--paper-300);
    border-radius: 50%;
    content: attr(data-step);
    font-size: 0.68rem;
  }

  .lesson-index li[data-state="active"] {
    color: var(--ink-950);
    font-weight: 730;
  }

  .lesson-index li[data-state="done"]::before {
    border-color: var(--moss-700);
    background: var(--moss-700);
    color: var(--white);
    content: "✓";
  }

  .callout {
    border-left: 4px solid var(--vermillion-500);
    background: var(--vermillion-100);
    padding: 17px 19px;
  }

  .callout--ink {
    border-color: var(--ink-900);
    background: #e7ebef;
  }

  .callout--success {
    border-color: var(--moss-700);
    background: var(--moss-100);
  }

  .callout strong {
    display: block;
    margin-bottom: 3px;
  }

  .theory-block {
    display: grid;
    gap: var(--space-4);
  }

  .theory-block__formula {
    border-block: 1px solid var(--paper-300);
    padding-block: var(--space-4);
    color: var(--ink-900);
    font-family: var(--font-jp-sans);
    font-size: clamp(1.35rem, 3vw, 2.25rem);
    line-height: 1.6;
    overflow-wrap: anywhere;
  }

  .example-list {
    display: grid;
    gap: 12px;
    list-style: none;
  }

  .example-item {
    display: grid;
    grid-template-columns: minmax(180px, 0.8fr) 1fr;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding: 12px 0 18px;
  }

  .example-item__jp {
    font-family: var(--font-jp-sans);
    font-size: var(--step-1);
  }

  .example-item__reading {
    display: block;
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .example-item__it {
    color: var(--ink-700);
  }

  .sentence-canvas {
    display: flex;
    min-height: 100px;
    flex-wrap: wrap;
    align-items: center;
    gap: 9px;
    border: 1px dashed var(--ink-300);
    background: var(--paper-50);
    padding: 18px;
  }

  .sentence-block {
    display: inline-grid;
    min-width: 74px;
    min-height: 58px;
    place-items: center;
    border: 1px solid var(--ink-300);
    border-bottom-width: 4px;
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-950);
    padding: 8px 12px;
    font-family: var(--font-jp-sans);
    font-size: 1.08rem;
  }

  .sentence-block small {
    color: var(--ink-500);
    font-family: var(--font-ui);
    font-size: 0.62rem;
    font-weight: 740;
    letter-spacing: 0.06em;
    text-transform: uppercase;
  }

  .sentence-block[data-role="topic"] {
    border-bottom-color: var(--vermillion-500);
  }

  .sentence-block[data-role="time"] {
    border-bottom-color: var(--gold-700);
  }

  .sentence-block[data-role="place"] {
    border-bottom-color: var(--moss-700);
  }

  .sentence-block[data-role="object"] {
    border-bottom-color: #6c5797;
  }

  .sentence-block[data-role="verb"] {
    border-bottom-color: var(--ink-900);
  }

  button.sentence-block {
    cursor: grab;
  }

  button.sentence-block:hover {
    translate: 0 -2px;
    box-shadow: 0 6px 14px rgb(21 40 63 / 11%);
  }

  .token-bank {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    min-height: 64px;
    padding-block: 12px;
  }

  .token {
    min-height: 42px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-950);
    padding: 8px 13px;
    font-family: var(--font-jp-sans);
  }

  .token:hover {
    border-color: var(--vermillion-500);
  }

  .token[disabled] {
    background: var(--paper-200);
    text-decoration: line-through;
  }

  .option-list {
    display: grid;
    gap: 9px;
    margin-block: var(--space-4);
  }

  .option-button {
    display: grid;
    grid-template-columns: 34px minmax(0, 1fr);
    align-items: center;
    gap: 12px;
    min-height: 58px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-950);
    padding: 10px 15px;
    text-align: left;
  }

  .option-button::before {
    display: grid;
    width: 28px;
    height: 28px;
    place-items: center;
    border: 1px solid var(--ink-300);
    border-radius: 50%;
    content: attr(data-letter);
    font-size: 0.72rem;
    font-weight: 800;
  }

  .option-button:hover,
  .option-button[aria-pressed="true"] {
    border-color: var(--vermillion-500);
  }

  .option-button[aria-pressed="true"]::before {
    border-color: var(--vermillion-500);
    background: var(--vermillion-500);
    color: var(--white);
  }

  .feedback {
    display: none;
    border-left: 4px solid var(--ink-900);
    background: #e7ebef;
    padding: 15px 17px;
  }

  .feedback[data-visible="true"] {
    display: block;
    animation: reveal 220ms ease both;
  }

  .feedback[data-correct="true"] {
    border-color: var(--success);
    background: var(--moss-100);
  }

  .feedback[data-correct="false"] {
    border-color: var(--danger);
    background: #f6dede;
  }

  .audio-panel {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: var(--space-4);
    border-block: 1px solid var(--paper-300);
    padding-block: var(--space-4);
  }

  .audio-trigger {
    display: grid;
    width: 74px;
    height: 74px;
    place-items: center;
    border-radius: 50%;
    background: var(--ink-900);
    color: var(--paper-50);
    font-size: 1.35rem;
    box-shadow: 0 0 0 8px var(--paper-200);
  }

  .audio-trigger[data-playing="true"] {
    background: var(--vermillion-600);
    animation: audioPulse 1.4s ease-in-out infinite;
  }

  .audio-copy strong {
    display: block;
  }

  .audio-copy small {
    display: block;
    color: var(--ink-500);
  }

  .audio-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 9px;
    margin-top: 8px;
  }

  .audio-controls select {
    min-height: 38px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    padding: 6px 9px;
  }

  .transcript {
    display: grid;
    gap: 5px;
    border-left: 2px solid var(--paper-300);
    padding-left: var(--space-3);
  }

  .transcript[hidden] {
    display: none;
  }

  .transcript__jp {
    font-family: var(--font-jp-sans);
    font-size: var(--step-1);
  }

  .transcript__reading,
  .transcript__translation {
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .reading-sheet {
    border-left: 2px solid var(--vermillion-500);
    background: var(--paper-50);
    padding: clamp(18px, 4vw, 34px);
  }

  .reading-sheet__jp {
    font-family: var(--font-jp-sans);
    font-size: clamp(1.12rem, 2.2vw, 1.5rem);
    line-height: 2;
  }

  ruby rt {
    color: var(--ink-500);
    font-size: 0.48em;
  }

  .kana-toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
  }

  .kana-board {
    display: grid;
    grid-template-columns: repeat(10, minmax(48px, 1fr));
    gap: 7px;
    margin-block: var(--space-4);
  }

  .kana-tile {
    position: relative;
    display: grid;
    aspect-ratio: 1;
    place-items: center;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-950);
    font-family: var(--font-jp-sans);
    font-size: clamp(1.35rem, 3vw, 2rem);
  }

  .kana-tile:hover {
    border-color: var(--vermillion-500);
  }

  .kana-tile small {
    position: absolute;
    right: 4px;
    bottom: 2px;
    color: var(--ink-500);
    font-family: var(--font-ui);
    font-size: 0.56rem;
  }

  .kana-tile[data-mastered="true"]::before {
    position: absolute;
    top: 5px;
    left: 5px;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--moss-700);
    content: "";
  }

  .kana-focus {
    display: grid;
    grid-template-columns: minmax(180px, 0.6fr) 1fr;
    gap: var(--space-5);
    align-items: center;
  }

  .kana-focus__glyph {
    display: grid;
    aspect-ratio: 1;
    place-items: center;
    border: 1px solid var(--paper-300);
    background:
      linear-gradient(90deg, transparent 49.5%, var(--paper-300) 50%, transparent 50.5%),
      linear-gradient(transparent 49.5%, var(--paper-300) 50%, transparent 50.5%),
      var(--white);
    font-family: var(--font-jp-sans);
    font-size: clamp(6rem, 17vw, 11rem);
  }

  .quiz-glyph {
    display: grid;
    min-height: 240px;
    place-items: center;
    border-block: 1px solid var(--paper-300);
    color: var(--ink-900);
    font-family: var(--font-jp-sans);
    font-size: clamp(7rem, 22vw, 14rem);
    line-height: 1;
  }

  .recorder {
    display: grid;
    gap: var(--space-3);
    border: 1px solid var(--paper-300);
    background: var(--paper-50);
    padding: var(--space-4);
  }

  .recorder__status {
    display: flex;
    align-items: center;
    gap: 9px;
    color: var(--ink-700);
    font-size: var(--step--1);
  }

  .recorder__dot {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--ink-300);
  }

  .recorder[data-recording="true"] .recorder__dot {
    background: var(--vermillion-500);
    animation: blink 1s ease-in-out infinite;
  }

  .recorder audio {
    width: 100%;
  }

  .review-card {
    display: grid;
    min-height: 430px;
    grid-template-rows: auto 1fr auto;
    border-top: 5px solid var(--vermillion-500);
    padding: clamp(24px, 5vw, 52px);
  }

  .review-card__prompt {
    display: grid;
    place-items: center;
    padding-block: var(--space-6);
    text-align: center;
  }

  .review-card__jp {
    font-family: var(--font-jp-sans);
    font-size: clamp(2rem, 7vw, 4.5rem);
  }

  .review-card__answer {
    display: grid;
    gap: 8px;
    border-top: 1px solid var(--paper-300);
    padding-top: var(--space-4);
  }

  .rating-row {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 8px;
    margin-top: var(--space-3);
  }

  .rating-button {
    min-height: 58px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    color: var(--ink-900);
  }

  .rating-button:hover {
    border-color: var(--vermillion-500);
  }

  .rating-button small {
    display: block;
    color: var(--ink-500);
    font-size: 0.68rem;
  }

  .mastery-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-3);
  }

  .mastery-card {
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: center;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding: 16px 0;
  }

  .mastery-card__score {
    display: grid;
    width: 68px;
    height: 68px;
    place-items: center;
    border: 5px solid var(--paper-300);
    border-radius: 50%;
    font-family: var(--font-display);
    font-size: 1.15rem;
  }

  .mastery-card h3 {
    font-family: var(--font-ui);
    font-size: var(--step-0);
  }

  .mastery-card p {
    color: var(--ink-500);
    font-size: var(--step--1);
  }

  .history-list {
    display: grid;
    gap: 0;
    list-style: none;
  }

  .history-row {
    display: grid;
    grid-template-columns: 90px minmax(0, 1fr) auto;
    gap: var(--space-3);
    border-bottom: 1px solid var(--paper-300);
    padding: 14px 0;
    font-size: var(--step--1);
  }

  .history-row time,
  .history-row span:last-child {
    color: var(--ink-500);
  }

  .empty-state {
    display: grid;
    min-height: 300px;
    place-content: center;
    gap: var(--space-2);
    border: 1px dashed var(--paper-300);
    padding: var(--space-5);
    text-align: center;
  }

  .empty-state p {
    color: var(--ink-500);
  }

  .dialog-backdrop {
    position: fixed;
    z-index: 100;
    inset: 0;
    display: grid;
    place-items: center;
    background: rgb(16 29 44 / 58%);
    padding: var(--space-3);
  }

  .dialog {
    width: min(100%, 620px);
    max-height: min(90vh, 760px);
    overflow-y: auto;
    border: 0;
    border-top: 5px solid var(--vermillion-500);
    background: var(--white);
    box-shadow: var(--shadow-lift);
    padding: clamp(22px, 5vw, 44px);
  }

  .dialog > * + * {
    margin-top: var(--space-3);
  }

  .toast-region {
    position: fixed;
    z-index: 200;
    right: 18px;
    bottom: 18px;
    display: grid;
    width: min(calc(100% - 36px), 380px);
    gap: 8px;
  }

  .toast {
    border-left: 4px solid var(--vermillion-500);
    background: var(--ink-900);
    color: var(--paper-50);
    box-shadow: var(--shadow-lift);
    padding: 13px 15px;
    animation: toastIn 220ms ease both;
  }

  .badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    border: 1px solid var(--paper-300);
    border-radius: 2px;
    background: var(--paper-50);
    color: var(--ink-700);
    padding: 3px 7px;
    font-size: 0.7rem;
    font-weight: 760;
    letter-spacing: 0.04em;
    text-transform: uppercase;
  }

  .badge--accent {
    border-color: var(--vermillion-500);
    color: var(--vermillion-700);
  }

  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    clip-path: inset(50%);
    white-space: nowrap;
  }

  @keyframes reveal {
    from {
      opacity: 0;
      translate: 0 5px;
    }
  }

  @keyframes audioPulse {
    50% {
      box-shadow: 0 0 0 14px var(--vermillion-100);
    }
  }

  @keyframes blink {
    50% {
      opacity: 0.25;
    }
  }

  @keyframes toastIn {
    from {
      opacity: 0;
      translate: 0 12px;
    }
  }
}

@layer components {
  .practice-dakuten-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 10px;
  }

  .practice-dakuten-cell {
    display: grid;
    grid-template-columns: auto auto auto auto auto 1fr;
    align-items: center;
    gap: 5px;
    border: 1px solid var(--paper-300);
    border-radius: var(--radius-xs);
    background: var(--white);
    padding: 10px 12px;
    font-size: var(--step--1);
  }

  .practice-dakuten-cell small {
    grid-column: 1 / -1;
    color: var(--ink-500);
    font-size: 0.62rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
  }

  .practice-dakuten-base {
    font-family: var(--font-jp-sans);
    font-size: var(--step-1);
    color: var(--ink-500);
  }

  .practice-dakuten-arrow {
    color: var(--ink-300);
    font-size: 0.75rem;
  }

  .practice-dakuten-daku {
    font-family: var(--font-jp-sans);
    font-size: var(--step-1);
    color: var(--vermillion-700);
  }

  .practice-dakuten-handaku {
    font-family: var(--font-jp-sans);
    font-size: var(--step-1);
    color: var(--moss-700);
  }
}

@layer utilities {
  .flow > * + * {
    margin-top: var(--space-3);
  }

  .flow-lg > * + * {
    margin-top: var(--space-5);
  }

  .spacer-top {
    margin-top: var(--space-5);
  }

  .text-center {
    text-align: center;
  }

  .jp {
    font-family: var(--font-jp-sans);
  }

  [hidden] {
    display: none !important;
  }
}

@layer responsive {
  @media (max-width: 1080px) {
    .dashboard-grid,
    .lesson-layout {
      grid-template-columns: 1fr;
    }

    .lesson-aside {
      position: static;
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .kana-board {
      grid-template-columns: repeat(8, minmax(46px, 1fr));
    }
  }

  @media (max-width: 820px) {
    .sidebar {
      display: none;
    }

    .mobile-header {
      position: sticky;
      z-index: 30;
      top: 0;
      display: flex;
      min-height: 64px;
      align-items: center;
      justify-content: space-between;
      border-bottom: 1px solid var(--paper-300);
      background: rgb(244 239 229 / 94%);
      backdrop-filter: blur(12px);
      padding: 10px 18px;
    }

    .mobile-header .brand {
      color: var(--ink-950);
    }

    .mobile-header .brand__mark {
      width: 38px;
      border-color: var(--ink-300);
      color: var(--ink-950);
    }

    .mobile-header .brand__tagline {
      color: var(--ink-500);
    }

    .mobile-nav {
      position: fixed;
      z-index: 40;
      right: 0;
      bottom: 0;
      left: 0;
      display: grid;
      grid-template-columns: repeat(5, minmax(0, 1fr));
      border-top: 1px solid var(--paper-300);
      background: rgb(255 253 248 / 96%);
      padding: 6px max(6px, env(safe-area-inset-right)) max(6px, env(safe-area-inset-bottom)) max(6px, env(safe-area-inset-left));
      backdrop-filter: blur(14px);
    }

    .mobile-nav .nav-link {
      display: grid;
      min-height: 54px;
      grid-template-columns: 1fr;
      place-items: center;
      gap: 0;
      color: var(--ink-500);
      padding: 3px;
      text-align: center;
    }

    .mobile-nav .nav-link__icon {
      width: auto;
    }

    .mobile-nav .nav-link__label {
      font-size: 0.62rem;
    }

    .mobile-nav .nav-link[aria-current="page"] {
      border-color: transparent;
      background: transparent;
      color: var(--vermillion-700);
    }

    .mobile-nav .nav-link[aria-current="page"]::before {
      display: none;
    }

    .main-stage {
      margin-left: 0;
      padding: 12px 20px calc(90px + env(safe-area-inset-bottom));
    }

    .milestone {
      grid-template-columns: 1fr;
      gap: var(--space-3);
    }

    .view-header {
      margin-block: var(--space-4) var(--space-5);
    }

    .metric-strip {
      grid-template-columns: repeat(3, 1fr);
    }

    .metric:nth-child(4),
    .metric:nth-child(5) {
      border-top: 1px solid var(--paper-300);
    }

    .metric:nth-child(4) {
      border-left: 0;
    }

    .level-band {
      grid-template-columns: 1fr;
      gap: var(--space-3);
    }

    .level-band__label {
      position: static;
    }

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

    .onboarding__story {
      min-height: 290px;
    }

    .onboarding__story h1 {
      max-width: 13ch;
    }

    .onboarding__form {
      padding-block: var(--space-6);
    }

    .kana-board {
      grid-template-columns: repeat(6, minmax(44px, 1fr));
    }
  }

  @media (max-width: 560px) {
    .main-stage {
      padding-inline: 14px;
    }

    .view-header,
    .section-heading,
    .today-card__footer,
    .form-actions {
      align-items: stretch;
      grid-template-columns: 1fr;
    }

    .view-header {
      display: grid;
    }

    .view-header > .button,
    .section-heading > .button {
      width: 100%;
    }

    .split-grid,
    .three-grid,
    .choice-grid,
    .mastery-grid,
    .lesson-aside {
      grid-template-columns: 1fr;
    }

    .today-card {
      min-height: 430px;
      padding: 25px 20px;
    }

    .today-card::after {
      top: 16px;
      right: -92px;
    }

    .side-card {
      padding: 22px;
    }

    .metric-strip {
      grid-template-columns: repeat(2, 1fr);
    }

    .metric:nth-child(3) {
      border-top: 1px solid var(--paper-300);
      border-left: 0;
    }

    .metric:nth-child(4) {
      border-left: 1px solid var(--paper-300);
    }

    .metric:nth-child(5) {
      border-left: 0;
    }

    .thread-item {
      grid-template-columns: 42px minmax(0, 1fr);
    }

    .thread-item__dot {
      width: 40px;
      height: 40px;
    }

    .thread-list::before {
      left: 19px;
    }

    .thread-item > :last-child {
      grid-column: 2;
    }

    .module-row {
      grid-template-columns: 1fr;
    }

    .module-row__meta {
      white-space: normal;
    }

    .lock-label {
      max-width: none;
      text-align: left;
    }

    .lesson-sheet {
      min-height: 0;
      padding: 24px 18px;
    }

    .example-item,
    .kana-focus,
    .audio-panel {
      grid-template-columns: 1fr;
    }

    .audio-trigger {
      width: 64px;
      height: 64px;
    }

    .kana-board {
      grid-template-columns: repeat(5, minmax(42px, 1fr));
      gap: 5px;
    }

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

    .history-row {
      grid-template-columns: 74px minmax(0, 1fr);
    }

    .history-row span:last-child {
      grid-column: 2;
    }
  }

  @media (prefers-reduced-motion: reduce) {
    html {
      scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
      scroll-behavior: auto !important;
      transition-duration: 0.01ms !important;
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
    }
  }

  @media (prefers-contrast: more) {
    :root {
      --paper-300: #9c8f7d;
      --ink-500: #405166;
    }

    .surface,
    .choice-card,
    .option-button,
    .token,
    .kana-tile {
      border-width: 2px;
    }
  }

  @media print {
    .sidebar,
    .mobile-header,
    .mobile-nav,
    .button,
    .icon-button,
    .toast-region {
      display: none !important;
    }

    .main-stage {
      margin: 0;
      padding: 0;
    }

    body {
      background: white;
    }

    .surface {
      box-shadow: none;
    }
  }
}