:root {
  color-scheme: light;
  --page-bg: #f7fbff;
  --surface: #ffffff;
  --surface-soft: #fffaf2;
  --surface-mint: #f0fff8;
  --ink: #233044;
  --muted: #637083;
  --line: #dce7ee;
  --accent-peach: #ffb38a;
  --accent-mint: #8be4bd;
  --accent-sky: #83c5ff;
  --accent-lemon: #ffe27a;
  --accent-rose: #ff8fb3;
  --green: #16805d;
  --amber: #a66a00;
  --red: #b42318;
  --blue: #266bd7;
  --shadow: 0 18px 34px rgba(35, 48, 68, 0.09);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    repeating-linear-gradient(0deg, rgba(131, 197, 255, 0.09) 0 1px, transparent 1px 42px),
    linear-gradient(180deg, #f7fbff 0%, #fff7ed 48%, #f3fff8 100%);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

button,
input,
select {
  font: inherit;
}

button,
select {
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 7px 12px;
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 160ms ease, background-color 160ms ease, box-shadow 160ms ease;
}

button:hover,
select:hover {
  border-color: var(--blue);
  box-shadow: 0 4px 12px rgba(38, 107, 215, 0.11);
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
.quiz-options label:focus-within {
  outline: 3px solid rgba(255, 179, 138, 0.55);
  outline-offset: 2px;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 22px;
  align-items: stretch;
  padding: 28px 52px;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(90deg, rgba(255, 226, 122, 0.34), transparent 54%),
    linear-gradient(180deg, #ffffff 0%, #fffaf2 100%);
  box-shadow: var(--shadow);
}

.brand-block {
  display: grid;
  align-content: center;
  gap: 10px;
  min-width: 0;
}

.brand-block h1,
.panel h2 {
  margin: 0;
  letter-spacing: 0;
}

.brand-block h1 {
  max-width: 720px;
  font-size: 42px;
  line-height: 1.08;
}

.lede {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 16px;
}

.eyebrow {
  margin: 0 0 6px;
  color: #22745e;
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero-points,
.segmented,
.level-filter,
.button-row,
.word-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.hero-points span,
.pill,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 3px 9px;
  background: #ffffff;
  color: #22745e;
  font-size: 12px;
  font-weight: 850;
}

.hero-points span:nth-child(1) {
  border-color: rgba(131, 197, 255, 0.75);
  background: #eef8ff;
  color: #225f9f;
}

.hero-points span:nth-child(2) {
  border-color: rgba(255, 226, 122, 0.9);
  background: #fff8d8;
  color: #775100;
}

.hero-points span:nth-child(3) {
  border-color: rgba(139, 228, 189, 0.85);
  background: #eafff5;
  color: #22745e;
}

.hero-visual {
  display: grid;
  grid-template-columns: minmax(150px, 0.9fr) minmax(160px, 1.1fr);
  gap: 16px;
  align-items: center;
  min-height: 196px;
  border: 1px solid #f1d8bd;
  border-radius: 8px;
  padding: 18px;
  background:
    repeating-linear-gradient(90deg, rgba(255, 179, 138, 0.13) 0 12px, transparent 12px 24px),
    linear-gradient(135deg, #fff7ed 0%, #f0fff8 100%);
}

.study-buddy {
  display: block;
  width: 100%;
  max-width: 230px;
  min-width: 130px;
  justify-self: center;
}

.hero-note {
  display: grid;
  gap: 6px;
  min-width: 0;
}

.hero-note strong {
  font-size: 19px;
}

.hero-note span {
  color: var(--muted);
}

.layout {
  width: min(1280px, calc(100% - 32px));
  margin: 22px auto 48px;
  display: grid;
  gap: 18px;
}

.toolbar,
.metrics,
.grid {
  display: grid;
  gap: 14px;
}

.toolbar {
  grid-template-columns: minmax(230px, 0.8fr) minmax(340px, 1fr) minmax(270px, 0.8fr);
  align-items: end;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 10px 24px rgba(35, 48, 68, 0.06);
}

.auth-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, auto);
  gap: 14px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background:
    linear-gradient(90deg, rgba(131, 197, 255, 0.13), transparent 62%),
    rgba(255, 255, 255, 0.96);
  box-shadow: 0 10px 24px rgba(35, 48, 68, 0.06);
}

.auth-copy h2,
.auth-copy p {
  margin: 0;
}

.auth-actions {
  display: grid;
  justify-items: end;
  gap: 8px;
}

.cloud-sync-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.cloud-sync-actions button {
  border-color: #b7f1d7;
  background: #eafff5;
  color: #22745e;
}

.cloud-sync-actions button:disabled {
  cursor: not-allowed;
  opacity: 0.58;
}

.google-signin-button {
  min-height: 44px;
  display: grid;
  align-items: center;
  justify-items: end;
}

.auth-help {
  max-width: 360px;
  margin: 0;
  color: var(--muted);
  font-size: 12px;
}

.mobile-quick-nav {
  display: none;
}

.mobile-quick-nav a {
  flex: 0 0 auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 11px;
  background: #ffffff;
  color: #205d9c;
  font-size: 13px;
  font-weight: 850;
  text-decoration: none;
  white-space: nowrap;
}

.segmented .active,
.level-filter .active,
.button-row .primary {
  border-color: #83c5ff;
  background: #eef8ff;
  color: #205d9c;
  font-weight: 850;
}

.search-box {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 850;
}

.search-box input,
.word-form input {
  width: 100%;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  background: var(--surface);
  color: var(--ink);
}

.metrics {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.metrics article,
.panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 8px 22px rgba(35, 48, 68, 0.05);
}

.metrics article {
  min-height: 96px;
  padding: 14px;
  border-top: 4px solid var(--accent-sky);
}

.metrics article:nth-child(2) {
  border-top-color: var(--accent-lemon);
}

.metrics article:nth-child(3) {
  border-top-color: var(--accent-rose);
}

.metrics article:nth-child(4) {
  border-top-color: var(--accent-mint);
}

.metrics span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 850;
  text-transform: uppercase;
}

.metrics strong {
  display: block;
  margin-top: 6px;
  font-size: 30px;
}

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

.learning-grid {
  grid-template-columns: minmax(320px, 0.95fr) minmax(360px, 1.05fr);
}

.panel {
  padding: 16px;
  overflow-x: auto;
}

.panel-title {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: start;
  margin-bottom: 12px;
}

.task-list,
.compact-list,
.word-list {
  display: grid;
  gap: 10px;
}

.task-item,
.compact-item,
.word-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background:
    linear-gradient(90deg, rgba(139, 228, 189, 0.12), transparent 60%),
    var(--surface);
}

.task-item strong,
.compact-item strong,
.word-card strong {
  display: block;
}

.tag.weak,
.tag.high-risk {
  color: var(--red);
  background: #fff1f0;
  border-color: #ffd1cc;
}

.tag.mastered {
  color: var(--green);
  background: #eafff5;
  border-color: #b7f1d7;
}

.flashcard {
  display: grid;
  min-height: 260px;
  align-content: center;
  gap: 12px;
  border: 1px solid #f1d8bd;
  border-radius: 8px;
  padding: 22px;
  background:
    repeating-linear-gradient(0deg, rgba(255, 226, 122, 0.15) 0 10px, transparent 10px 20px),
    linear-gradient(135deg, #fffaf2 0%, #f0fff8 100%);
}

.flashcard .word {
  overflow-wrap: anywhere;
  font-size: 48px;
  line-height: 1.05;
  font-weight: 850;
}

.flashcard .meaning {
  font-size: 18px;
  color: var(--ink);
}

.flashcard .example,
.compact-item p,
.word-card p,
.task-item p {
  margin: 4px 0 0;
  color: var(--muted);
}

.quiz-box {
  display: grid;
  gap: 12px;
  min-height: 260px;
  border: 1px solid #cfe9f8;
  border-radius: 8px;
  padding: 16px;
  background:
    repeating-linear-gradient(90deg, rgba(131, 197, 255, 0.12) 0 14px, transparent 14px 28px),
    #f8fcff;
}

.quiz-question {
  overflow-wrap: anywhere;
  font-size: 20px;
  font-weight: 850;
}

.quiz-options {
  display: grid;
  gap: 8px;
}

.quiz-options label {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  background: var(--surface);
}

.mistake-item {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
}

.mistake-actions {
  flex: 0 0 auto;
}

button.danger {
  border-color: #ffd1cc;
  background: #fff1f0;
  color: var(--red);
}

.feedback {
  min-height: 24px;
  margin: 10px 0 0;
  font-weight: 850;
}

.feedback.pass {
  color: var(--green);
}

.feedback.fail {
  color: var(--red);
}

.word-form {
  display: grid;
  gap: 10px;
}

.word-card {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) minmax(0, 1.3fr) auto;
  gap: 12px;
  align-items: start;
}

.word-meta {
  margin-top: 8px;
}

.word-audio-controls,
.familiarity-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 10px;
}

.word-audio-controls button {
  min-height: 32px;
  padding: 5px 10px;
  border-color: #cfe9f8;
  background: #eef8ff;
  color: #205d9c;
}

.familiarity-label {
  color: var(--muted);
  font-size: 12px;
  font-weight: 850;
}

.familiarity-controls button {
  min-height: 32px;
  padding: 5px 9px;
  border-color: #f1d8bd;
  background: #fffaf2;
}

.familiarity-controls button.active {
  border-color: var(--accent-mint);
  background: #eafff5;
  color: #22745e;
  font-weight: 850;
}

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

@media (max-width: 980px) {
  .app-shell,
  .auth-panel,
  .toolbar,
  .grid.two,
  .learning-grid {
    grid-template-columns: 1fr;
  }

  .app-shell {
    padding: 24px 28px;
  }

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

  .word-card {
    grid-template-columns: 1fr;
  }

  .auth-actions,
  .cloud-sync-actions,
  .google-signin-button {
    justify-items: start;
  }

  .cloud-sync-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 720px) {
  .app-shell {
    padding: 22px 18px;
  }

  .brand-block h1 {
    font-size: 34px;
  }

  .hero-visual,
  .toolbar,
  .grid.two,
  .learning-grid,
  .word-card {
    grid-template-columns: 1fr;
  }

  .panel-title {
    display: grid;
  }

  .mistake-item {
    display: grid;
  }

  .auth-panel {
    padding: 14px;
  }

  .mobile-quick-nav {
    position: sticky;
    top: 0;
    z-index: 5;
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: rgba(255, 250, 242, 0.96);
    box-shadow: 0 8px 18px rgba(35, 48, 68, 0.08);
  }
}

@media (max-width: 560px) {
  .layout {
    width: min(100% - 20px, 1280px);
  }

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

  .brand-block h1 {
    font-size: 29px;
  }

  .flashcard .word {
    font-size: 36px;
  }

  button,
  select,
  .button-row button,
  .cloud-sync-actions button,
  .auth-actions,
  .google-signin-button {
    width: 100%;
  }
}