/* === UI kit === */

/* Base layout & typography */
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-family-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: var(--font-size-base);
}

.fullscreen-static {
  min-height: 100vh;
  min-height: 100dvh;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  overscroll-behavior: none;
}

.app-shell {
  min-height: 100vh;
  background-color: var(--color-bg);
  display: flex;
  flex-direction: column;
}

.app-container {
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  padding: var(--space-lg) var(--page-horizontal-padding) var(--space-2xl);
  box-sizing: border-box;
}

.app-shell .app-container {
  padding-bottom: calc(var(--bottom-nav-total-height) + var(--bottom-nav-clearance));
}

main {
  flex: 1 1 auto;
  overflow-x: hidden;
}

.section {
  margin: var(--space-xl) 0 0;
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.section:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-title {
  font-size: 1.95rem;
  font-weight: var(--font-weight-semibold);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

.section-title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-md);
}


.card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: var(--space-lg);
  box-sizing: border-box;
}


@media (max-width: 480px) {
  .app-container {
    padding-left: calc(var(--page-horizontal-padding) * 0.75);
    padding-right: calc(var(--page-horizontal-padding) * 0.75);
  }
}

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  background-color: var(--color-surface);
  box-shadow: none;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.button:focus {
  outline: none;
}

.button:hover {
  background-color: var(--color-surface-muted);
  box-shadow: var(--shadow-subtle);
}

.button:active {
  background-color: var(--color-surface-muted);
  box-shadow: none;
}

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

.button--primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  box-shadow: none;
}

.button--primary:active {
  background: var(--color-primary-hover);
  box-shadow: none;
}

.button--primary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.button--secondary {
  background: var(--color-primary-soft);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.button--secondary:hover {
  background: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: var(--shadow-subtle);
}

.button--secondary:active {
  background: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: none;
}

.button--download {
  width: 100%;
  max-width: none;
  height: 48px;
  border-radius: var(--radius-md);
  padding: 0 1.25rem;
  margin: 0;
  font-size: 1rem;
  font-weight: var(--font-weight-medium);
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-on-primary);
  box-shadow: var(--shadow-subtle);
}

.button--download:hover,
.button--download:active,
.button--download.button--secondary,
.button--download.button--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-on-primary);
  box-shadow: var(--shadow-subtle);
}

.button--download.is-loading {
  visibility: hidden;
}

/* Chips / badges */
.chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  font-weight: var(--font-weight-medium);
  font-family: inherit;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  white-space: nowrap;
  color: var(--color-text-muted);
  background-color: var(--color-surface);
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.chip--interactive {
  cursor: pointer;
}

.chip--interactive:hover {
  background-color: var(--color-surface-muted);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.chip--interactive.chip--active {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.chip--tag {
  cursor: default;
  padding: 0.25rem 0.75rem;
  font-size: 15px;
  font-weight: inherit;
  font-family: inherit;
  color: var(--color-text-muted);
  background-color: var(--color-bg);
  border-color: var(--color-border);
}

/* Typography utilities */
.text-body {
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text-muted);
}

/* Utility */
.load-error {
  margin: 0;
  font-size: var(--font-size-sm);
  color: var(--color-danger);
}

/* Cards */
.material-card {
  flex: 0 0 140px;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  cursor: pointer;
  user-select: none;
  scroll-snap-align: start;
  color: var(--color-text);
  text-decoration: none;
}

.material-card--narrow {
  flex-basis: 140px;
}

.material-card__cover {
  width: 100%;
  aspect-ratio: 2 / 3;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  flex-shrink: 0;
}

@supports not (aspect-ratio: 2 / 3) {
  .material-card__cover {
    position: relative;
    padding-top: 150%;
  }
}

.material-card__title {
  margin: 0;
  font-size: 0.95rem;
  font-weight: var(--font-weight-semibold);
  line-height: 1.2;
  color: var(--color-text);
}

.catalog-card {
  display: flex;
  gap: var(--space-md);
  align-items: center;
}

.catalog-card__cover {
  flex: 0 0 96px;
  width: 96px;
  aspect-ratio: 2 / 3;
  border-radius: var(--radius-lg);
  background-position: center;
  background-size: cover;
  background-color: var(--color-cover-placeholder);
  box-shadow: var(--shadow-card);
  text-decoration: none;
}

.catalog-card__info {
  flex: 1 1 auto;
  min-width: 0;
}

.catalog-card__title {
  margin: 0;
  font-size: 1rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
}

.catalog-card__title-link {
  color: inherit;
  text-decoration: none;
}

.catalog-card__title-link:hover {
  text-decoration: underline;
}

@media (max-width: 480px) {
  .material-card {
    flex-basis: 120px;
  }

  .material-card__title {
    font-size: 0.9rem;
  }

  .catalog-card__cover {
    flex-basis: 84px;
    width: 84px;
  }
}

/* Scroll containers / carousels */
.materials-section {
  margin-bottom: 2rem;
}

.materials-section__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0;
  margin-bottom: 0.75rem;
}

.materials-section__title {
  margin: 0;
  font-size: clamp(1.1rem, 0.9rem + 0.8vw, 1.4rem);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.01em;
}

.materials-carousel {
  display: flex;
  gap: var(--space-lg);
  overflow-x: auto;
  padding: 0;
  scroll-snap-type: x mandatory;
  -ms-overflow-style: none;
  scrollbar-width: none;
}

.materials-carousel::-webkit-scrollbar {
  display: none;
  width: 0;
  height: 0;
}

.catalog-categories {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  padding: 0.75rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  -ms-overflow-style: none;
  scrollbar-width: none;
}

.catalog-categories::-webkit-scrollbar {
  display: none;
  width: 0;
  height: 0;
}

.catalog-categories__button {
  display: flex;
  align-items: stretch;
  background: none;
  border: none;
  padding: 0;
  flex: 0 0 auto;
  cursor: pointer;
}

.catalog-categories__button .chip {
  padding: 0.5rem 1.2rem;
  border-radius: var(--radius-pill);
  font-size: 1rem;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  border-color: var(--color-neutral-weak-strong);
}

.catalog-categories__button .chip.chip--active,
.catalog-categories__button:focus .chip.chip--active {
  color: var(--color-text-on-primary);
  background: var(--color-primary);
  border-color: var(--color-primary);
}

@media (max-width: 480px) {
  .materials-section {
    margin-bottom: 1.5rem;
  }

  .materials-carousel {
    gap: var(--space-md);
  }
}

/* Navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--bottom-nav-height);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-around;
  align-items: center;
  box-shadow: var(--shadow-float);
  padding-bottom: var(--bottom-nav-safe-area);
}

.bottom-nav__button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: max(56px, var(--bottom-nav-height));
  height: var(--bottom-nav-height);
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
}

.bottom-nav__icon {
  display: block;
  width: var(--bottom-nav-icon-size);
  height: var(--bottom-nav-icon-size);
  color: var(--color-text-muted);
  transition: color 0.2s ease, opacity 0.2s ease;
}

.bottom-nav__icon use {
  pointer-events: none;
}

@media (hover: hover) and (pointer: fine) {
  .bottom-nav__button:hover .bottom-nav__icon {
    color: var(--color-primary-hover);
  }
}

.bottom-nav__button:focus-visible .bottom-nav__icon {
  color: var(--color-primary);
}

.bottom-nav__button.bottom-nav__button--active .bottom-nav__icon {
  color: var(--color-primary);
}