:root {
  color-scheme: light;
  --page-pearl: #f7f9fd;
  --page-ice: #eaf2ff;
  --page-peach: #fff0ea;
  --page-lilac: #f1efff;
  --text: #1d1d1f;
  --text-secondary: #5d616a;
  --text-tertiary: #767b86;
  --accent: #0878ed;
  --accent-hover: #006edb;
  --accent-soft: rgba(0, 122, 255, 0.1);
  --accent-soft-strong: rgba(0, 122, 255, 0.16);
  --success: #2f7d57;
  --favorite: #d5425b;
  --separator: rgba(74, 88, 116, 0.14);
  --separator-strong: rgba(74, 88, 116, 0.22);
  --glass-strong-bg: rgba(255, 255, 255, 0.46);
  --glass-soft-bg: rgba(255, 255, 255, 0.28);
  --glass-control-bg: rgba(255, 255, 255, 0.4);
  --glass-border: rgba(255, 255, 255, 0.78);
  --glass-inner-border: rgba(255, 255, 255, 0.42);
  --glass-shadow: rgba(67, 85, 125, 0.13);
  --glass-contact: rgba(67, 85, 125, 0.08);
  --radius-large: 28px;
  --radius-card: 22px;
  --radius-control: 14px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  min-height: 100%;
  overflow-x: clip;
  background: var(--page-pearl);
  font-size: 100%;
}

body {
  min-width: 0;
  min-height: 100%;
  overflow-x: clip;
  color: var(--text);
  background:
    radial-gradient(ellipse 54% 48% at 13% 17%, rgba(190, 218, 255, 0.68) 0%, rgba(212, 230, 255, 0.34) 42%, transparent 74%),
    radial-gradient(ellipse 48% 44% at 91% 12%, rgba(255, 214, 200, 0.6) 0%, rgba(255, 234, 225, 0.26) 48%, transparent 76%),
    radial-gradient(ellipse 46% 54% at 24% 88%, rgba(255, 224, 209, 0.54) 0%, rgba(255, 239, 232, 0.2) 48%, transparent 76%),
    radial-gradient(ellipse 46% 46% at 86% 76%, rgba(205, 217, 255, 0.48) 0%, rgba(232, 234, 255, 0.18) 52%, transparent 78%),
    linear-gradient(135deg, var(--page-pearl) 0%, #f8fbff 43%, #fff9f7 72%, #f2f5ff 100%);
  background-attachment: fixed;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button {
  font: inherit;
}

/*
 * Web glass approximation. Strong, soft and control variants share the same
 * double-edge construction so refraction stays consistent across the page.
 */
.glass-surface {
  --glass-radius: var(--radius-card);
  --glass-bg: var(--glass-soft-bg);
  --glass-blur: 22px;
  --glass-saturation: 150%;
  position: relative;
  isolation: isolate;
  overflow: hidden;
  border: 1px solid var(--glass-border);
  border-radius: var(--glass-radius);
  background:
    linear-gradient(136deg, rgba(255, 255, 255, 0.3) 0%, rgba(255, 255, 255, 0.04) 44%, rgba(226, 234, 251, 0.12) 100%),
    var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
  box-shadow:
    0 22px 60px var(--glass-shadow),
    0 4px 14px var(--glass-contact),
    inset 0 1px 0 rgba(255, 255, 255, 0.92),
    inset 0 -1px 0 rgba(255, 255, 255, 0.24);
}

.glass-surface::before,
.glass-surface::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.glass-surface::before {
  inset: 2px;
  z-index: 2;
  border: 1px solid var(--glass-inner-border);
  border-radius: calc(var(--glass-radius) - 2px);
  box-shadow:
    inset 1px 1px 0 rgba(255, 255, 255, 0.36),
    inset -1px -1px 0 rgba(92, 111, 148, 0.06);
}

.glass-surface::after {
  inset: -1px;
  z-index: 3;
  border-radius: inherit;
  padding: 1.5px;
  background:
    radial-gradient(circle at 1% 1%, rgba(255, 255, 255, 0.98) 0 2px, rgba(255, 255, 255, 0.4) 12px, transparent 42px),
    radial-gradient(circle at 99% 99%, rgba(255, 255, 255, 0.72) 0 2px, rgba(117, 137, 176, 0.14) 15px, transparent 46px),
    linear-gradient(136deg, rgba(255, 255, 255, 0.88) 0%, rgba(255, 255, 255, 0.16) 38%, rgba(112, 132, 170, 0.16) 100%);
  -webkit-mask:
    linear-gradient(#000 0 0) content-box,
    linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask:
    linear-gradient(#000 0 0) content-box,
    linear-gradient(#000 0 0);
  mask-composite: exclude;
}

.glass-surface > * {
  position: relative;
  z-index: 1;
}

.glass-strong {
  --glass-radius: var(--radius-large);
  --glass-bg: var(--glass-strong-bg);
  --glass-blur: 30px;
  --glass-saturation: 155%;
}

.glass-soft {
  --glass-radius: var(--radius-card);
  --glass-bg: var(--glass-soft-bg);
  --glass-blur: 20px;
  --glass-saturation: 145%;
}

.glass-control {
  --glass-radius: 50%;
  --glass-bg: var(--glass-control-bg);
  --glass-blur: 14px;
  --glass-saturation: 155%;
}

.layout {
  display: grid;
  min-height: 100dvh;
  grid-template-columns: 272px minmax(0, 1fr);
  align-items: start;
  gap: 30px;
  padding: 12px;
}

.sidebar {
  position: sticky;
  top: 12px;
  z-index: 5;
  display: flex;
  width: 272px;
  height: calc(100dvh - 24px);
  min-height: 620px;
  flex-direction: column;
  padding: 22px 16px;
}

.sidebar-brand {
  display: inline-flex;
  width: fit-content;
  min-height: 40px;
  align-items: center;
  gap: 10px;
  margin: 0 10px 18px;
  color: var(--text);
  font-size: 19px;
  font-weight: 680;
  letter-spacing: -0.03em;
}

.sidebar-brand-mark {
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: linear-gradient(145deg, #303035, #151518);
  color: #f8f8fa;
  font-size: 18px;
  font-weight: 720;
  letter-spacing: -0.04em;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 4px 12px rgba(28, 31, 40, 0.2);
}

.sidebar-brand:focus-visible,
.pn-btn:focus-visible,
.nav-item:focus-visible,
.translate-feature:focus-visible,
.lc-card-link:focus-visible,
.lc-btn:focus-visible {
  outline: 3px solid rgba(0, 122, 255, 0.38);
  outline-offset: 3px;
}

.page-nav {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
  padding: 0 8px 16px;
  border-bottom: 1px solid rgba(90, 104, 132, 0.12);
}

.pn-btn {
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: #626874;
  cursor: pointer;
  transition:
    color 180ms ease,
    background-color 180ms ease,
    transform 180ms var(--ease-out);
}

.pn-btn:active {
  transform: scale(0.98);
}

.pn-home {
  margin-left: auto;
}

.mute-btn .icon-active {
  display: none;
}

.mute-btn.is-muted .icon-inactive {
  display: none;
}

.mute-btn.is-muted .icon-active {
  display: block;
}

.mute-btn.is-muted {
  color: var(--favorite);
  background: rgba(213, 66, 91, 0.09);
}

.side-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.nav-item {
  display: flex;
  min-height: 54px;
  align-items: center;
  gap: 12px;
  padding: 11px 13px;
  border: 1px solid transparent;
  border-radius: var(--radius-control);
  color: #555c68;
  cursor: pointer;
  font-size: 15px;
  font-weight: 530;
  transition:
    color 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease,
    box-shadow 220ms ease,
    transform 180ms var(--ease-out);
}

.nav-item:active {
  transform: scale(0.98);
}

.nav-item.active {
  border-color: rgba(255, 255, 255, 0.76);
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.62), rgba(227, 239, 255, 0.3)),
    rgba(0, 122, 255, 0.08);
  color: var(--accent);
  font-weight: 650;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.86),
    0 8px 24px rgba(55, 99, 166, 0.08);
}

.ni-icon {
  display: inline-flex;
  width: 22px;
  height: 22px;
  flex: 0 0 22px;
  align-items: center;
  justify-content: center;
  color: currentColor;
}

.nav-item.heart .ni-icon {
  color: var(--favorite);
}

.ni-label {
  min-width: 0;
  flex: 1;
}

.ni-count {
  min-width: 22px;
  color: var(--text-secondary);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.nav-item.with-arrow {
  margin-top: 10px;
}

.nav-item.with-arrow .ni-arrow {
  display: inline-flex;
  color: var(--text-tertiary);
}

.nav-item.core-entry {
  min-height: 72px;
  margin-top: 14px;
  border-color: rgba(255, 255, 255, 0.82);
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.62), rgba(255, 255, 255, 0.28)),
    rgba(255, 255, 255, 0.24);
  color: var(--text);
  box-shadow:
    0 12px 30px rgba(67, 85, 125, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.96);
}

.core-entry .ni-icon,
.core-entry .ni-arrow {
  color: var(--accent);
}

.core-entry .ni-label {
  font-weight: 660;
  letter-spacing: -0.01em;
}

.core-entry .ni-label small {
  display: block;
  margin-top: 2px;
  color: var(--text-tertiary);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0;
}

.sidebar-decor {
  display: none;
}

.content {
  width: min(100%, 1264px);
  min-width: 0;
  margin-inline: auto;
  padding: 24px 12px 64px 0;
}

.translate-feature {
  display: grid;
  min-height: 224px;
  grid-template-columns:
    minmax(340px, 1.25fr)
    clamp(112px, 11vw, 148px)
    minmax(310px, 0.88fr);
  align-items: center;
  gap: clamp(20px, 2.2vw, 34px);
  margin-bottom: var(--space-4);
  padding: 28px clamp(28px, 3vw, 40px);
  transition:
    border-color 220ms ease,
    box-shadow 220ms ease,
    transform 180ms var(--ease-out);
}

.translate-feature:active {
  transform: scale(0.998);
}

.translate-feature-copy {
  min-width: 0;
}

.translate-feature-kicker {
  display: block;
  width: fit-content;
  margin-bottom: 6px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 680;
  letter-spacing: -0.01em;
}

.translate-feature h1 {
  color: var(--text);
  font-size: clamp(36px, 3vw, 46px);
  font-weight: 720;
  line-height: 1.08;
  letter-spacing: -0.045em;
}

.translate-feature-copy p {
  max-width: 33rem;
  margin-top: 8px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.55;
}

.translate-feature-action {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  padding: 10px 18px;
  border-radius: 13px;
  background: var(--accent);
  color: #f7fbff;
  font-size: 14px;
  font-weight: 650;
  line-height: 1;
  white-space: nowrap;
  box-shadow:
    0 8px 18px rgba(0, 113, 227, 0.2),
    inset 0 1px 0 rgba(255, 255, 255, 0.24);
  transition:
    background-color 180ms ease,
    transform 180ms var(--ease-out);
}

.translate-feature-action span {
  font-size: 18px;
  line-height: 0.8;
  transition: transform 180ms var(--ease-out);
}

.translate-feature-mascot {
  align-self: end;
  justify-self: center;
  width: min(100%, 138px);
  margin-bottom: -8px;
}

.translate-feature-mascot img {
  display: block;
  width: 100%;
  height: auto;
  filter: drop-shadow(0 12px 16px rgba(30, 39, 58, 0.14));
}

.translate-feature-visual {
  --glass-radius: 18px;
  display: flex;
  min-width: 0;
  min-height: 132px;
  flex-direction: column;
  justify-content: center;
  padding: 20px;
  border-color: rgba(255, 255, 255, 0.72);
  background:
    linear-gradient(140deg, rgba(255, 255, 255, 0.42), rgba(255, 255, 255, 0.12)),
    rgba(255, 255, 255, 0.16);
  box-shadow:
    0 12px 30px rgba(67, 85, 125, 0.07),
    inset 0 1px 0 rgba(255, 255, 255, 0.76),
    inset 0 -1px 0 rgba(103, 119, 151, 0.08);
}

.tf-structure-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
}

.tf-structure-heading span,
.tf-structure-heading strong {
  color: var(--text);
  font-size: 16px;
  font-weight: 670;
  letter-spacing: -0.015em;
}

.tf-structure-heading strong {
  color: var(--accent);
}

.tf-structure-flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
}

.tf-structure-flow span {
  min-width: 0;
  padding: 10px 6px;
  border: 1px solid rgba(98, 111, 140, 0.16);
  border-radius: 11px;
  background: rgba(255, 255, 255, 0.34);
  color: var(--text);
  font-size: 13px;
  font-weight: 620;
  text-align: center;
  white-space: nowrap;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.7),
    0 4px 14px rgba(67, 85, 125, 0.04);
}

.tf-structure-flow b {
  color: var(--text-tertiary);
  font-size: 14px;
  font-weight: 560;
}

.grammar-section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 18px;
  padding: 0 2px;
}

.grammar-section-head h2 {
  color: var(--text);
  font-size: 25px;
  font-weight: 710;
  letter-spacing: -0.035em;
}

.grammar-section-head span {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 520;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.lesson-card {
  --glass-radius: var(--radius-card);
  min-width: 0;
  border-color: rgba(255, 255, 255, 0.74);
  background:
    linear-gradient(155deg, rgba(255, 255, 255, 0.28), rgba(247, 250, 255, 0.08)),
    rgba(255, 255, 255, 0.24);
  box-shadow:
    0 14px 32px rgba(67, 85, 125, 0.09),
    0 3px 10px rgba(67, 85, 125, 0.06),
    inset 0 1px 0 rgba(255, 255, 255, 0.86),
    inset 0 -1px 0 rgba(255, 255, 255, 0.2);
  transition:
    border-color 220ms ease,
    box-shadow 220ms ease,
    transform 220ms var(--ease-out);
}

.lc-card-link {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  transition: transform 180ms var(--ease-out);
}

.lc-card-link:active {
  transform: scale(0.98);
}

.lc-image {
  position: relative;
  width: 100%;
  aspect-ratio: 2.02 / 1;
  overflow: hidden;
  background: rgba(227, 233, 243, 0.56);
}

.lc-image::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 1px;
  background: rgba(255, 255, 255, 0.52);
  pointer-events: none;
}

.lc-photo {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.93) contrast(0.98);
  transition:
    filter 240ms ease,
    transform 260ms var(--ease-out);
}

.lc-btn {
  position: absolute;
  top: 14px;
  z-index: 4;
  display: inline-flex;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  padding: 0;
  border-color: rgba(255, 255, 255, 0.76);
  color: #5d6571;
  cursor: pointer;
  box-shadow:
    0 6px 16px rgba(34, 48, 75, 0.14),
    inset 0 1px 0 rgba(255, 255, 255, 0.88);
  transition:
    color 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease,
    transform 180ms var(--ease-out);
}

.lc-btn:active {
  transform: scale(0.98);
}

.lc-btn .icon-active {
  display: none;
}

.lc-btn.is-active .icon-inactive {
  display: none;
}

.lc-btn.is-active .icon-active {
  display: block;
}

.lc-learned-btn {
  left: 14px;
}

.lc-fav-btn {
  right: 14px;
}

.lc-learned-btn.is-active {
  --glass-bg: rgba(255, 255, 255, 0.72);
  color: var(--success);
}

.lc-fav-btn.is-active {
  --glass-bg: rgba(255, 255, 255, 0.72);
  color: var(--favorite);
}

.lc-body {
  display: flex;
  min-width: 0;
  min-height: 124px;
  flex: 1;
  flex-direction: column;
  gap: 3px;
  padding: 14px 18px 17px;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.36), rgba(249, 251, 255, 0.16)),
    rgba(255, 255, 255, 0.1);
}

.lc-tag {
  display: -webkit-box;
  overflow: hidden;
  color: var(--text);
  font-size: 18px;
  font-weight: 680;
  letter-spacing: -0.02em;
  line-height: 1.3;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.lc-title {
  margin-top: 1px;
  color: var(--text-tertiary);
  font-size: 12px;
  font-weight: 570;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.lc-desc {
  display: -webkit-box;
  margin-top: 5px;
  overflow: hidden;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.5;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 72px 0;
  color: var(--text-secondary);
  font-size: 14px;
  text-align: center;
}

@media (max-width: 1199px) {
  .layout {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 24px;
  }

  .sidebar {
    width: 232px;
  }

  .content {
    padding-right: 8px;
  }

  .translate-feature {
    min-height: 0;
    grid-template-columns: minmax(0, 1fr) 112px;
    gap: 20px 24px;
  }

  .translate-feature-mascot {
    width: 106px;
    margin-bottom: -4px;
  }

  .translate-feature-visual {
    grid-column: 1 / -1;
    min-height: 116px;
  }

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

@media (max-width: 900px) and (min-width: 768px) {
  .layout {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 18px;
  }

  .sidebar {
    width: 216px;
    padding-inline: 12px;
  }

  .nav-item {
    gap: 9px;
    padding-inline: 10px;
    font-size: 14px;
  }

  .translate-feature {
    padding: 24px;
  }

  .translate-feature h1 {
    font-size: 34px;
  }
}

@media (max-width: 767px) {
  body {
    background-attachment: scroll;
  }

  .layout {
    display: block;
    width: 100%;
    min-width: 0;
    padding: 8px;
    overflow-x: clip;
  }

  .sidebar {
    --glass-radius: 22px;
    position: sticky;
    top: 8px;
    z-index: 8;
    width: 100%;
    height: auto;
    min-height: 0;
    padding: 10px 12px 12px;
  }

  .sidebar-brand {
    display: none;
  }

  .page-nav {
    margin-bottom: 8px;
    padding: 0 0 8px;
  }

  .side-nav {
    width: 100%;
    max-width: calc(100vw - 40px);
    flex-direction: row;
    gap: 7px;
    overflow-x: auto;
    padding-bottom: 1px;
    overscroll-behavior-inline: contain;
    scrollbar-width: none;
  }

  .side-nav::-webkit-scrollbar {
    display: none;
  }

  .nav-item {
    min-height: 42px;
    flex: 0 0 auto;
    padding: 8px 11px;
    font-size: 13px;
    white-space: nowrap;
  }

  .nav-item.core-entry {
    order: -1;
    min-height: 42px;
    margin-top: 0;
  }

  .core-entry .ni-label small,
  .core-entry .ni-arrow,
  .sidebar-decor {
    display: none;
  }

  .ni-count {
    min-width: 0;
    font-size: 12px;
  }

  .content {
    width: 100%;
    padding: 20px 0 48px;
  }

  .translate-feature {
    --glass-radius: 24px;
    min-height: 0;
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
    margin-bottom: 28px;
    padding: 24px 20px;
  }

  .translate-feature h1 {
    font-size: clamp(32px, 10vw, 39px);
  }

  .translate-feature-copy p {
    max-width: 31rem;
    font-size: 14px;
  }

  .translate-feature-mascot {
    width: 116px;
    align-self: center;
    justify-self: center;
    margin: -4px auto -8px;
  }

  .translate-feature-visual {
    grid-column: auto;
    min-height: 116px;
    padding: 17px;
  }

  .tf-structure-heading span,
  .tf-structure-heading strong {
    font-size: 15px;
  }

  .tf-structure-flow {
    gap: 5px;
  }

  .tf-structure-flow span {
    padding-inline: 4px;
    font-size: 12px;
  }

  .grammar-section-head {
    align-items: flex-start;
    flex-direction: column;
    gap: 2px;
    margin-bottom: 14px;
    padding-inline: 4px;
  }

  .grammar-section-head h2 {
    font-size: 23px;
  }

  .grammar-section-head span {
    font-size: 13px;
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .lesson-card {
    --glass-radius: 20px;
  }

  .lc-image {
    aspect-ratio: 1.84 / 1;
  }

  .lc-body {
    min-height: 126px;
    padding: 15px 17px 18px;
  }

  .lc-tag {
    font-size: 17px;
  }

  .lc-desc {
    -webkit-line-clamp: 3;
  }
}

@media (max-width: 390px) {
  .layout {
    padding: 6px;
  }

  .sidebar {
    top: 6px;
  }

  .content {
    padding-top: 16px;
  }

  .translate-feature {
    padding: 22px 17px;
  }

  .translate-feature-action {
    min-height: 42px;
    padding-inline: 16px;
  }

  .translate-feature-visual {
    padding: 16px 13px;
  }

  .tf-structure-flow {
    gap: 4px;
  }

  .lc-body {
    padding-inline: 16px;
  }
}

@media (hover: hover) and (pointer: fine) {
  .pn-btn:hover {
    background: rgba(255, 255, 255, 0.42);
    color: var(--text);
  }

  .nav-item:hover {
    border-color: rgba(255, 255, 255, 0.58);
    background: rgba(255, 255, 255, 0.28);
    color: var(--text);
  }

  .nav-item.active:hover {
    border-color: rgba(255, 255, 255, 0.82);
    background:
      linear-gradient(135deg, rgba(255, 255, 255, 0.72), rgba(227, 239, 255, 0.38)),
      rgba(0, 122, 255, 0.1);
    color: var(--accent);
  }

  .nav-item.core-entry:hover {
    border-color: rgba(0, 122, 255, 0.24);
    box-shadow:
      0 14px 34px rgba(67, 85, 125, 0.12),
      inset 0 1px 0 rgba(255, 255, 255, 0.98);
  }

  .translate-feature:hover {
    border-color: rgba(255, 255, 255, 0.92);
    box-shadow:
      0 26px 64px rgba(67, 85, 125, 0.15),
      0 5px 16px rgba(67, 85, 125, 0.09),
      inset 0 1px 0 rgba(255, 255, 255, 0.96),
      inset 0 -1px 0 rgba(255, 255, 255, 0.28);
  }

  .translate-feature:hover .translate-feature-action {
    background: var(--accent-hover);
  }

  .translate-feature:hover .translate-feature-action span {
    transform: translateX(2px);
  }

  .lesson-card:hover {
    border-color: rgba(255, 255, 255, 0.94);
    box-shadow:
      0 18px 38px rgba(67, 85, 125, 0.12),
      0 4px 12px rgba(67, 85, 125, 0.07),
      inset 0 1px 0 rgba(255, 255, 255, 0.94),
      inset 0 -1px 0 rgba(255, 255, 255, 0.24);
    transform: translateY(-3px);
  }

  .lesson-card:hover .lc-photo {
    filter: saturate(1) contrast(1);
    transform: scale(1.008);
  }

  .lc-btn:hover {
    --glass-bg: rgba(255, 255, 255, 0.62);
    border-color: rgba(255, 255, 255, 0.94);
    color: var(--text);
  }
}

@supports not ((-webkit-backdrop-filter: blur(1px)) or (backdrop-filter: blur(1px))) {
  .glass-strong {
    --glass-bg: rgba(250, 252, 255, 0.94);
  }

  .glass-soft {
    --glass-bg: rgba(252, 253, 255, 0.88);
  }

  .glass-control {
    --glass-bg: rgba(252, 253, 255, 0.94);
  }
}

@media (prefers-reduced-transparency: reduce) {
  .glass-surface {
    --glass-bg: rgba(250, 252, 255, 0.96);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  .translate-feature-visual,
  .lesson-card,
  .lc-body {
    background-color: rgba(250, 252, 255, 0.96);
  }
}

@media (prefers-contrast: more) {
  :root {
    --text-secondary: #444850;
    --text-tertiary: #595e68;
    --glass-border: rgba(75, 88, 115, 0.46);
    --glass-inner-border: rgba(255, 255, 255, 0.76);
  }

  .glass-surface {
    border-width: 2px;
  }
}

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

  .pn-btn,
  .nav-item,
  .translate-feature,
  .translate-feature-action,
  .translate-feature-action span,
  .lesson-card,
  .lc-card-link,
  .lc-photo,
  .lc-btn {
    transition-duration: 0.01ms;
  }

  .translate-feature:hover,
  .translate-feature:active,
  .lesson-card:hover,
  .lesson-card:hover .lc-photo,
  .lc-card-link:active,
  .pn-btn:active,
  .nav-item:active,
  .lc-btn:active,
  .translate-feature:hover .translate-feature-action span {
    transform: none;
  }
}