:root {
  --color-primary: #4f46e5;
  --color-on-primary: #ffffff;
  --color-secondary: #818cf8;
  --color-accent: #16a34a;
  --color-background: #eef2ff;
  --color-foreground: #312e81;
  --color-muted: #ebeef8;
  --color-border: #c7d2fe;
  --color-destructive: #dc2626;
  --color-ring: #4f46e5;
  --color-paper: #fffdf8;
  --color-surface: #f8f9ff;
  --color-soft: #4338ca;
  --font-ui: "Baloo 2", "Noto Sans SC", "Segoe UI", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", serif;
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --radius-chip: 20px;
  --radius-card: 32px;
  --radius-outer: 40px;
  --shadow-clay:
    8px 10px 24px rgba(79, 70, 229, 0.12),
    -6px -6px 18px rgba(255, 255, 255, 0.92),
    inset 0 1px 0 rgba(255, 255, 255, 0.85);
  --shadow-clay-pressed:
    2px 3px 8px rgba(79, 70, 229, 0.16),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  --shadow-focus: 0 0 0 3px #4f46e533;
  --topbar-h: 76px;
  --content-max: 46rem;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-body);
  color: var(--color-foreground);
  background: var(--color-background);
  line-height: 1.75;
  overflow-x: hidden;
}

img,
svg {
  display: block;
}

a {
  color: var(--color-primary);
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 80;
  padding: 8px 14px;
  border-radius: 999px;
  background: var(--color-primary);
  color: var(--color-on-primary);
  text-decoration: none;
}

.skip-link:focus {
  top: calc(8px + env(safe-area-inset-top));
}

.blobs {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.blobs::before,
.blobs::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(30px);
}

.blobs::before {
  width: min(52vw, 420px);
  height: min(52vw, 420px);
  top: -80px;
  right: -60px;
  background: #c7d2fe;
  opacity: 0.7;
  animation: drift 18s ease-in-out infinite;
}

.blobs::after {
  width: min(48vw, 360px);
  height: min(48vw, 360px);
  bottom: 8%;
  left: -80px;
  background: #a7f3d0;
  opacity: 0.35;
  animation: drift 22s ease-in-out infinite reverse;
}

@keyframes drift {
  0%,
  100% {
    transform: translate(0, 0);
  }
  50% {
    transform: translate(16px, -18px);
  }
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  min-height: var(--topbar-h);
  padding: calc(8px + env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) 8px max(12px, env(safe-area-inset-left));
  background: rgba(238, 242, 255, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  min-height: 44px;
}

.brand .icon {
  width: 40px;
  height: 40px;
  padding: 8px;
  border-radius: 16px;
  color: var(--color-primary);
  background: var(--color-surface);
  box-shadow: var(--shadow-clay);
}

.eyebrow {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-soft);
}

.brand-title {
  display: block;
  font-family: var(--font-ui);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.1;
}

.progress {
  margin: 0;
  min-height: 44px;
  padding: 8px 14px;
  border-radius: var(--radius-chip);
  background: var(--color-surface);
  box-shadow: var(--shadow-clay);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-end;
}

.progress-label {
  font-size: 0.72rem;
  color: var(--color-soft);
}

.progress-value {
  font-family: var(--font-ui);
  font-weight: 700;
  color: var(--color-accent);
}

.shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  padding: 0 0 calc(var(--space-3xl) + env(safe-area-inset-bottom));
}

.day-rail {
  position: sticky;
  top: var(--topbar-h);
  z-index: 40;
  background: rgba(248, 249, 255, 0.94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 8px 18px rgba(79, 70, 229, 0.06);
  padding: 8px max(12px, env(safe-area-inset-right)) 10px max(12px, env(safe-area-inset-left));
}

.rail-kicker {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-soft);
}

.rail-title {
  margin: 2px 0 8px;
  font-family: var(--font-ui);
  font-size: 0.98rem;
  font-weight: 700;
}

.day-chips {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 2px 4px 8px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-x: contain;
  scrollbar-width: none;
}

.day-chips::-webkit-scrollbar {
  display: none;
}

.day-chip {
  flex: 0 0 auto;
  scroll-snap-align: start;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 44px;
  min-width: 44px;
  padding: 8px 14px;
  border-radius: var(--radius-chip);
  background: #fff;
  color: var(--color-foreground);
  text-decoration: none;
  font-family: var(--font-ui);
  font-weight: 600;
  box-shadow: var(--shadow-clay);
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  transition: box-shadow 200ms ease, color 200ms ease, background 200ms ease;
}

.day-chip:hover {
  box-shadow: 10px 12px 24px rgba(79, 70, 229, 0.16), -4px -4px 12px rgba(255, 255, 255, 0.95);
}

.day-chip:focus-visible,
.btn:focus-visible,
.toc-link:focus-visible,
.brand:focus-visible,
.goal input:focus-visible {
  outline: 3px solid var(--color-ring);
  outline-offset: 2px;
}

.day-chip.is-current {
  background: linear-gradient(180deg, #6366f1, #4f46e5);
  color: var(--color-on-primary);
  box-shadow:
    0 10px 20px rgba(79, 70, 229, 0.32),
    inset 0 1px 0 rgba(255, 255, 255, 0.35);
}

.day-chip.is-latest:not(.is-current) {
  box-shadow:
    var(--shadow-clay),
    0 0 0 2px var(--color-accent);
}

.chip-new {
  font-size: 0.7rem;
  padding: 2px 7px;
  border-radius: 999px;
  background: var(--color-accent);
  color: white;
}

.day-chip.is-current .chip-new {
  background: rgba(255, 255, 255, 0.2);
}

.lesson {
  min-width: 0;
  max-width: var(--content-max);
  margin: 0 auto;
  width: 100%;
  padding: 14px max(16px, env(safe-area-inset-right)) 0 max(16px, env(safe-area-inset-left));
}

.clay {
  background: var(--color-surface);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-clay);
}

.hero {
  padding: 18px 16px;
  margin-bottom: var(--space-md);
}

.kicker {
  margin: 0 0 8px;
  font-family: var(--font-ui);
  font-size: 0.95rem;
  color: var(--color-primary);
}

.hero h1,
.lesson-body h1 {
  margin: 0 0 10px;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  line-height: 1.35;
}

.theme,
.topic,
.minutes {
  margin: 0 0 6px;
}

.theme {
  font-weight: 700;
}

.topic {
  color: var(--color-soft);
}

.minutes {
  display: inline-block;
  margin-top: 10px;
  padding: 6px 12px;
  border-radius: 999px;
  background: #dcfce7;
  color: #166534;
  font-size: 0.9rem;
}

.toc {
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
  margin: 0 0 var(--space-lg);
  overflow-x: auto;
  padding: 2px 2px 8px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-x: contain;
  scrollbar-width: none;
}

.toc::-webkit-scrollbar {
  display: none;
}

.toc-link {
  flex: 0 0 auto;
  min-height: 44px;
  max-width: min(72vw, 16rem);
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 16px;
  background: var(--color-surface);
  color: var(--color-foreground);
  text-decoration: none;
  font-size: 0.86rem;
  line-height: 1.25;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  box-shadow: var(--shadow-clay);
  cursor: pointer;
  scroll-snap-align: start;
  transition: box-shadow 200ms ease;
  touch-action: manipulation;
}

.toc-link:hover {
  box-shadow: 8px 10px 18px rgba(79, 70, 229, 0.16);
}

.block {
  background: var(--color-surface);
  border-radius: 24px;
  box-shadow: var(--shadow-clay);
  padding: 16px;
  margin-bottom: var(--space-md);
}

.block[data-kind="reading"] {
  background: var(--color-paper);
}

.block[data-kind="tip"] {
  background: #fff7ed;
}

.block[data-kind="goals"] {
  background: #f0fdf4;
}

.block[data-kind="vocab"] {
  background: #f5f3ff;
}

.lesson-body h2 {
  margin: 0 0 var(--space-md);
  font-size: 1.18rem;
  scroll-margin-top: calc(var(--topbar-h) + 108px);
}

.lesson-body h3 {
  margin: 1.4em 0 0.6em;
  font-size: 1.05rem;
}

.lesson-body p {
  margin: 0 0 0.9em;
  overflow-wrap: anywhere;
}

.lesson-body li {
  overflow-wrap: anywhere;
}

.lesson-body ul,
.lesson-body ol {
  margin: 0 0 1em;
  padding-left: 1.2em;
}

.lesson-body li + li {
  margin-top: 0.35em;
}

.lesson-body hr {
  border: 0;
  height: 1px;
  background: var(--color-border);
  margin: 1.4em 0;
}

blockquote {
  margin: 1em 0;
  padding: 14px 16px;
  border-radius: 20px;
  background: rgba(79, 70, 229, 0.06);
  border-left: 4px solid var(--color-primary);
}

.block[data-kind="reading"] p,
.block[data-kind="listening"] blockquote {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.9;
}

.table-wrap {
  overflow-x: auto;
  margin: 1em 0;
  border-radius: 16px;
  -webkit-overflow-scrolling: touch;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 0;
  background: #fff;
}

th,
td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

th {
  font-size: 0.85rem;
  color: var(--color-soft);
  background: var(--color-muted);
}

td:first-child {
  font-weight: 700;
  font-size: 1.05rem;
}

td:nth-child(2) {
  color: var(--color-primary);
}

code {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.9em;
  background: var(--color-muted);
  padding: 0.1em 0.35em;
  border-radius: 6px;
}

.goal-list {
  list-style: none;
  padding: 0;
}

.goal {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-height: 44px;
  cursor: pointer;
}

.goal input {
  appearance: none;
  width: 22px;
  height: 22px;
  margin: 4px 0 0;
  flex: 0 0 22px;
  border-radius: 8px;
  border: 2px solid var(--color-border);
  background: #fff;
  box-shadow: var(--shadow-clay);
  cursor: pointer;
}

.goal input:checked {
  background: var(--color-accent);
  border-color: var(--color-accent);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='none' stroke='white' stroke-width='2' d='M3 8.5 6.5 12 13 4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
}

.goal:has(input:checked) span {
  color: #166534;
  text-decoration: line-through;
}

.pager {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: var(--space-lg);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  min-height: 48px;
  padding: 12px 20px;
  border-radius: var(--radius-chip);
  text-decoration: none;
  font-family: var(--font-ui);
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  transition: box-shadow 200ms ease, opacity 200ms ease;
}

.btn .icon {
  width: 18px;
  height: 18px;
}

.btn-primary {
  background: linear-gradient(180deg, #34d399, #16a34a);
  color: white;
  box-shadow: 0 10px 18px rgba(22, 163, 74, 0.28), inset 0 1px 0 rgba(255, 255, 255, 0.35);
}

.btn-secondary {
  background: #fff;
  color: var(--color-primary);
  box-shadow: var(--shadow-clay);
}

.btn:hover {
  box-shadow: 0 12px 22px rgba(79, 70, 229, 0.18);
}

.btn.is-disabled {
  opacity: 0.5;
  cursor: default;
  pointer-events: none;
}

@media (min-width: 640px) {
  .pager {
    flex-direction: row;
    justify-content: space-between;
  }

  .btn {
    width: auto;
  }

  table {
    min-width: 480px;
  }
}

@media (max-width: 639px) {
  :root {
    --topbar-h: 64px;
  }

  .rail-kicker {
    display: none;
  }

  .rail-title {
    margin: 0 0 6px;
  }
  thead {
    display: none;
  }

  table,
  tbody,
  tr,
  td {
    display: block;
    width: 100%;
  }

  tr {
    background: #fff;
    border-radius: 16px;
    padding: 10px 12px;
    margin-bottom: 8px;
    box-shadow: 0 4px 10px rgba(79, 70, 229, 0.06);
  }

  th,
  td {
    border-bottom: 0;
    padding: 2px 0;
  }

  td:first-child {
    font-size: 1.15rem;
  }

  .progress-label {
    display: none;
  }

  .progress {
    min-width: 52px;
    align-items: center;
    padding: 8px 10px;
  }

  .brand-title {
    font-size: 1.05rem;
  }

  .clay,
  .hero {
    border-radius: 24px;
  }

  .hero h1 {
    font-size: 1.45rem;
  }

  .block[data-kind="reading"] p,
  .block[data-kind="listening"] blockquote {
    font-size: 1.02rem;
    line-height: 1.85;
  }
}

@media (min-width: 1024px) {
  .shell {
    grid-template-columns: 280px minmax(0, 1fr);
    align-items: start;
    max-width: 1180px;
    margin: 0 auto;
    gap: var(--space-lg);
    padding: var(--space-xl) max(16px, env(safe-area-inset-right)) var(--space-3xl) max(16px, env(safe-area-inset-left));
  }

  .day-rail {
    position: sticky;
    top: calc(var(--topbar-h) + 16px);
    border-radius: var(--radius-card);
    border-bottom: 0;
    background: var(--color-surface);
    box-shadow: var(--shadow-clay);
    padding: var(--space-lg);
  }

  .rail-kicker {
    font-size: 0.78rem;
  }

  .rail-title {
    margin: 4px 0 14px;
    font-size: 1.15rem;
  }

  .day-chips {
    flex-direction: column;
    overflow: visible;
    padding: 0;
  }

  .toc {
    flex-wrap: wrap;
    overflow: visible;
    padding: 0;
  }

  .toc-link {
    max-width: none;
  }

  .lesson {
    margin: 0;
    max-width: none;
    padding: 0;
  }

  .hero {
    padding: var(--space-xl) var(--space-lg);
    margin-bottom: var(--space-lg);
  }

  .block {
    padding: var(--space-lg);
    border-radius: var(--radius-card);
    margin-bottom: var(--space-lg);
  }

  .lesson-body h2 {
    font-size: 1.25rem;
    scroll-margin-top: calc(var(--topbar-h) + 16px);
  }
}

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

  .blobs::before,
  .blobs::after,
  .day-chip,
  .btn,
  .toc-link {
    animation: none;
    transition: none;
  }
}

@media print {
  .blobs,
  .day-rail,
  .topbar,
  .toc,
  .pager,
  .skip-link {
    display: none !important;
  }

  body,
  .block,
  .hero {
    background: #fff;
    box-shadow: none;
  }
}