:root {
  color-scheme: light dark;

  /* Эти переменные заменяются только после получения утверждённого бренда. */
  --brand-font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --brand-color-primary: Highlight;
  --brand-color-on-primary: HighlightText;
  --brand-color-accent: LinkText;

  --ui-page: Canvas;
  --ui-surface: Canvas;
  --ui-text: CanvasText;
  --ui-muted: GrayText;
  --ui-link: var(--brand-color-accent);
  --ui-border: GrayText;
  --ui-radius-small: 0.5rem;
  --ui-radius-medium: 0.875rem;
  --ui-radius-large: 1.25rem;
  --ui-content-width: 72rem;
  --ui-reading-width: 46rem;
}

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

html {
  min-width: 20rem;
  font-size: 100%;
  text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  margin: 0;
  background: var(--ui-page);
  color: var(--ui-text);
  font-family: var(--brand-font-family);
  font-size: 1rem;
  line-height: 1.55;
}

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

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

a {
  color: var(--ui-link);
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 0.14em;
}

:focus-visible {
  outline: 0.2rem solid var(--brand-color-primary);
  outline-offset: 0.18rem;
}

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

h1,
h2,
h3 {
  line-height: 1.18;
  overflow-wrap: anywhere;
}

h1 {
  margin-bottom: 1rem;
  font-size: clamp(2rem, 5vw, 3.5rem);
  letter-spacing: -0.035em;
}

h2 {
  margin-bottom: 0.75rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
  letter-spacing: -0.02em;
}

h3 {
  margin-bottom: 0.75rem;
  font-size: 1.25rem;
}

.shell {
  width: min(100% - 2.5rem, var(--ui-content-width));
  margin-inline: auto;
}

.page-content {
  padding-block: clamp(2rem, 5vw, 4.5rem) 5rem;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.65rem 0.9rem;
  transform: translateY(-200%);
  border: 0.125rem solid var(--ui-text);
  border-radius: var(--ui-radius-small);
  background: var(--ui-surface);
  color: var(--ui-text);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  border-bottom: 0.0625rem solid var(--ui-border);
  background: var(--ui-surface);
}

.site-header__inner {
  display: flex;
  min-height: 5rem;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding-block: 0.8rem;
}

.brand-link {
  display: inline-flex;
  min-width: 0;
  align-items: center;
  gap: 1rem;
  color: var(--ui-text);
  text-decoration: none;
}

.brand-logo {
  width: auto;
  max-width: 11rem;
  height: 2.75rem;
  object-fit: contain;
  object-position: left center;
}

.brand-name {
  margin: 0;
  font-weight: 750;
  line-height: 1.15;
}

.brand-course {
  padding-left: 1rem;
  border-left: 0.0625rem solid var(--ui-border);
  color: var(--ui-muted);
  font-size: 0.9rem;
  font-weight: 650;
}

.account-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.account-actions form {
  margin: 0;
}

.account-name {
  max-width: 14rem;
  overflow: hidden;
  font-weight: 650;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.button {
  display: inline-flex;
  min-height: 3rem;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.15rem;
  border: 0.125rem solid var(--brand-color-primary);
  border-radius: var(--ui-radius-small);
  font-weight: 750;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
}

.button--primary {
  background: var(--brand-color-primary);
  color: var(--brand-color-on-primary);
}

.button--quiet {
  border-color: var(--ui-border);
  background: var(--ui-surface);
  color: var(--ui-text);
}

.button--compact {
  min-height: 2.75rem;
  padding: 0.55rem 0.9rem;
}

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

.eyebrow {
  margin-bottom: 0.55rem;
  color: var(--ui-muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.lead {
  max-width: 42rem;
  margin-bottom: 0;
  font-size: clamp(1.1rem, 2vw, 1.3rem);
}

.muted,
.progress-caption,
.login-help {
  color: var(--ui-muted);
}

.message-stack {
  display: grid;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.message {
  padding: 0.9rem 1rem;
  border: 0.0625rem solid var(--ui-border);
  border-left: 0.35rem solid var(--brand-color-primary);
  border-radius: var(--ui-radius-small);
  background: var(--ui-surface);
}

.message--error {
  border-left-color: var(--ui-text);
  font-weight: 650;
}

/* Login */

.page-login {
  min-height: 100vh;
}

.login-layout {
  display: grid;
  width: min(100% - 2rem, 32rem);
  min-height: 100vh;
  margin-inline: auto;
  place-items: center;
  padding-block: 2rem;
}

.login-card {
  width: 100%;
  padding: clamp(1.5rem, 6vw, 2.75rem);
  border: 0.0625rem solid var(--ui-border);
  border-radius: var(--ui-radius-large);
  background: var(--ui-surface);
}

.login-brand {
  margin-bottom: 2.5rem;
}

.login-logo {
  width: auto;
  max-width: 14rem;
  max-height: 4.25rem;
  object-fit: contain;
  object-position: left center;
}

.login-heading {
  margin-bottom: 1.75rem;
}

.login-heading h1 {
  font-size: clamp(2rem, 8vw, 2.75rem);
}

.login-heading .muted {
  margin-bottom: 0;
}

.login-form {
  display: grid;
  gap: 1.2rem;
}

.field-group {
  display: grid;
  gap: 0.4rem;
}

.field-group label {
  font-weight: 700;
}

.field-group input {
  width: 100%;
  min-height: 3.25rem;
  padding: 0.7rem 0.8rem;
  border: 0.125rem solid var(--ui-border);
  border-radius: var(--ui-radius-small);
  background: var(--ui-surface);
  color: var(--ui-text);
}

.field-group input:focus {
  border-color: var(--brand-color-primary);
}

.field-group--error input {
  border-style: double;
}

.field-error {
  margin-bottom: 0;
  font-size: 0.9rem;
  font-weight: 650;
}

.form-alert,
.notice,
.completion-banner {
  padding: 0.9rem 1rem;
  border: 0.0625rem solid var(--ui-border);
  border-left: 0.35rem solid var(--brand-color-primary);
  border-radius: var(--ui-radius-small);
  background: var(--ui-surface);
}

.form-alert {
  margin-bottom: 1.25rem;
  border-left-color: var(--ui-text);
}

.form-alert p,
.notice,
.completion-banner {
  margin-bottom: 0;
}

.release-notice {
  margin-top: 1.5rem;
}

.release-notice strong {
  display: block;
  margin-bottom: 0.35rem;
}

.release-notice p {
  margin: 0;
}

.login-help {
  margin: 1.5rem 0 0;
  font-size: 0.9rem;
}

/* Dashboard */

.dashboard-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(17rem, 24rem);
  gap: clamp(2rem, 6vw, 5rem);
  align-items: end;
  padding-bottom: clamp(2.5rem, 6vw, 5rem);
  border-bottom: 0.0625rem solid var(--ui-border);
}

.dashboard-hero > .button {
  grid-column: 1 / -1;
  width: fit-content;
  margin-top: -1rem;
}

.progress-panel {
  padding: 1.25rem;
  border: 0.0625rem solid var(--ui-border);
  border-radius: var(--ui-radius-medium);
  background: var(--ui-surface);
}

.progress-summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.progress-summary h2 {
  margin-bottom: 0.65rem;
  font-size: 1rem;
  letter-spacing: 0;
}

.progress-summary strong {
  font-size: 1.2rem;
}

progress {
  display: block;
  width: 100%;
  height: 0.8rem;
  overflow: hidden;
  border: 0;
  border-radius: 999px;
  accent-color: var(--brand-color-primary);
}

.progress-caption {
  margin: 0.6rem 0 0;
  font-size: 0.85rem;
}

.weeks-section,
.materials-section {
  padding-top: clamp(2.5rem, 6vw, 5rem);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
  margin-bottom: 1.5rem;
}

.section-heading > * {
  max-width: 38rem;
  margin-bottom: 0;
}

.week-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.week-card {
  display: flex;
  min-width: 0;
  min-height: 14rem;
  flex-direction: column;
  padding: 1.4rem;
  border: 0.0625rem solid var(--ui-border);
  border-radius: var(--ui-radius-medium);
  background: var(--ui-surface);
}

.week-card--locked {
  border-style: dashed;
}

.week-card__topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.week-card__topline .eyebrow {
  margin-bottom: 0;
}

.week-number {
  color: var(--ui-muted);
  font-size: 0.86rem;
  font-weight: 750;
}

.status-badge,
.completion-state {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.55rem;
  border: 0.0625rem solid var(--ui-border);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 750;
  line-height: 1.2;
}

.status-badge--open,
.completion-state--done {
  border-color: var(--brand-color-primary);
  background: var(--brand-color-primary);
  color: var(--brand-color-on-primary);
}

.status-badge--locked,
.locked-note {
  color: var(--ui-muted);
}

.week-card h3 {
  max-width: 28rem;
}

.week-card__progress {
  margin-bottom: 0;
}

.week-card__action {
  margin-top: auto;
  padding-top: 1.5rem;
}

.text-link {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  font-weight: 750;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 1.25rem;
  border: 0.0625rem dashed var(--ui-border);
  border-radius: var(--ui-radius-medium);
  color: var(--ui-muted);
}

/* Week */

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 2rem;
  color: var(--ui-muted);
  font-size: 0.9rem;
}

.week-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(17rem, 24rem);
  gap: clamp(2rem, 6vw, 5rem);
  align-items: end;
  padding-bottom: clamp(2rem, 5vw, 4rem);
  border-bottom: 0.0625rem solid var(--ui-border);
}

.week-header .week-card__topline {
  justify-content: flex-start;
  margin-bottom: 0.8rem;
}

.week-header h1 {
  margin-bottom: 0;
}

.progress-panel--compact {
  padding: 1rem;
}

.week-header + .notice {
  margin-top: 1.5rem;
}

.material-list {
  display: grid;
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.material-card {
  min-width: 0;
}

.material-card__link {
  display: grid;
  grid-template-columns: 2.75rem minmax(0, 1fr) auto;
  gap: 1rem;
  align-items: center;
  min-height: 6.5rem;
  padding: 1rem;
  border: 0.0625rem solid var(--ui-border);
  border-radius: var(--ui-radius-medium);
  background: var(--ui-surface);
  color: var(--ui-text);
  text-decoration: none;
}

.material-card__link:hover {
  border-color: var(--brand-color-primary);
}

.material-card__marker {
  display: inline-grid;
  width: 2.75rem;
  height: 2.75rem;
  place-items: center;
  border: 0.0625rem solid var(--ui-border);
  border-radius: 50%;
  font-weight: 800;
  text-transform: uppercase;
}

.material-card__content {
  min-width: 0;
}

.material-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1rem;
  margin-bottom: 0.25rem;
  color: var(--ui-muted);
  font-size: 0.82rem;
}

.material-card__title {
  display: block;
  overflow-wrap: anywhere;
}

.material-card__status {
  text-align: right;
}

/* Lesson */

.lesson-layout {
  width: min(100%, var(--ui-reading-width));
  margin-inline: auto;
}

.lesson-header {
  padding-bottom: 2rem;
  border-bottom: 0.0625rem solid var(--ui-border);
}

.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.25rem;
  margin-bottom: 1rem;
  color: var(--ui-muted);
  font-size: 0.9rem;
  font-weight: 650;
}

.lesson-copy {
  padding-block: clamp(2rem, 6vw, 4rem);
  font-size: 1.08rem;
  overflow-wrap: anywhere;
}

.lesson-copy > :first-child {
  margin-top: 0;
}

/* The page header already exposes the authoritative manifest title as h1. */
.lesson-copy > h1:first-child {
  display: none;
}

.lesson-copy > :last-child {
  margin-bottom: 0;
}

.lesson-copy h2,
.lesson-copy h3,
.lesson-copy h4 {
  margin-top: 2em;
  scroll-margin-top: 1rem;
}

.lesson-copy p,
.lesson-copy li {
  max-width: 72ch;
}

.lesson-copy li + li {
  margin-top: 0.45rem;
}

.lesson-copy img {
  height: auto;
  margin-block: 1.5rem;
}

.lesson-copy blockquote {
  margin: 1.5rem 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 0.25rem solid var(--brand-color-primary);
}

.lesson-copy pre,
.lesson-copy table {
  max-width: 100%;
  overflow-x: auto;
}

.lesson-copy pre {
  padding: 1rem;
  border: 0.0625rem solid var(--ui-border);
  border-radius: var(--ui-radius-small);
}

.lesson-copy table {
  display: block;
  border-collapse: collapse;
}

.lesson-copy th,
.lesson-copy td {
  padding: 0.6rem;
  border: 0.0625rem solid var(--ui-border);
  text-align: left;
}

.completion-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding: 1.25rem;
  border: 0.125rem solid var(--brand-color-primary);
  border-radius: var(--ui-radius-medium);
}

.completion-panel h2 {
  margin-bottom: 0.4rem;
  font-size: 1.25rem;
}

.completion-panel p {
  margin-bottom: 0;
}

.completion-panel form {
  flex: 0 0 auto;
  margin: 0;
}

.lesson-navigation {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  width: min(100%, var(--ui-reading-width));
  margin: 3rem auto 0;
  padding-top: 1.5rem;
  border-top: 0.0625rem solid var(--ui-border);
}

.lesson-navigation__next {
  text-align: right;
}

.lesson-navigation__link {
  display: inline-flex;
  min-height: 3rem;
  flex-direction: column;
  justify-content: center;
  overflow-wrap: anywhere;
}

.lesson-navigation__direction {
  color: var(--ui-muted);
  font-size: 0.8rem;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
}

@media (max-width: 48rem) {
  .shell {
    width: min(100% - 2rem, var(--ui-content-width));
  }

  .site-header__inner {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .brand-link {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.35rem;
  }

  .brand-course {
    padding-left: 0;
    border-left: 0;
  }

  .account-actions {
    margin-left: auto;
  }

  .account-name {
    max-width: 10rem;
  }

  .dashboard-hero,
  .week-header {
    grid-template-columns: 1fr;
  }

  .dashboard-hero > .button {
    margin-top: 0;
  }

  .section-heading {
    display: block;
  }

  .section-heading > * + * {
    margin-top: 0.75rem;
  }

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

  .week-card {
    min-height: 12rem;
  }

  .material-card__link {
    grid-template-columns: 2.75rem minmax(0, 1fr);
  }

  .material-card__status {
    grid-column: 2;
    text-align: left;
  }

  .completion-panel {
    align-items: stretch;
    flex-direction: column;
  }

  .completion-panel .button {
    width: 100%;
  }
}

@media (max-width: 30rem) {
  .site-header__inner {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 0.75rem;
  }

  .account-actions {
    display: block;
  }

  .account-name {
    display: block;
    max-width: 8rem;
    margin-bottom: 0.35rem;
    font-size: 0.85rem;
  }

  .button--compact {
    min-height: 2.75rem;
  }

  .login-layout {
    width: min(100% - 1rem, 32rem);
    padding-block: 0.5rem;
  }

  .login-card {
    padding: 1.25rem;
    border-radius: var(--ui-radius-medium);
  }

  .week-card__topline {
    align-items: flex-start;
  }

  .status-badge {
    max-width: 9rem;
    text-align: center;
  }

  .material-card__link {
    gap: 0.75rem;
    padding: 0.85rem;
  }

  .lesson-copy {
    font-size: 1rem;
  }

  .lesson-navigation {
    grid-template-columns: 1fr;
  }

  .lesson-navigation__next {
    text-align: left;
  }
}

@media (forced-colors: active) {
  .button,
  .status-badge--open,
  .completion-state--done {
    forced-color-adjust: auto;
  }
}