:root {
  --pico-font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --pico-background: #ffffff;
  --pico-color: #1c1c1e;
  --pico-muted: #6b7280;
  --pico-primary: #2563eb;
  --pico-primary-contrast: #ffffff;
  --pico-card-background: #f7f7f8;
  --pico-card-border: #e5e7eb;
  --pico-radius: 0.5rem;
  --pico-spacing: 1rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --pico-background: #111214;
    --pico-color: #e8e8ea;
    --pico-muted: #9ca3af;
    --pico-primary: #60a5fa;
    --pico-primary-contrast: #0b1220;
    --pico-card-background: #1a1c1f;
    --pico-card-border: #2a2d31;
  }
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--pico-font-family);
  line-height: 1.6;
  color: var(--pico-color);
  background: var(--pico-background);
}

.container {
  width: 100%;
  max-width: 720px;
  margin-inline: auto;
  padding-inline: 1rem;
}

.site-header {
  border-bottom: 1px solid var(--pico-card-border);
  padding-block: 0.75rem;
}

.brand {
  color: var(--pico-color);
  font-weight: 700;
  text-decoration: none;
}

main.container {
  flex: 1;
  padding-block: 2rem;
}

.site-footer {
  padding-block: 1.5rem;
  color: var(--pico-muted);
  text-align: center;
}

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0 0 0.5rem;
}

h1 {
  font-size: 1.75rem;
}

h2 {
  font-size: 1.25rem;
}

p {
  margin: 0 0 1rem;
}

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

.hero {
  margin-bottom: 2rem;
}

.card {
  background: var(--pico-card-background);
  border: 1px solid var(--pico-card-border);
  border-radius: var(--pico-radius);
  padding: 1.25rem;
  margin-bottom: var(--pico-spacing);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem;
  border: 1px solid var(--pico-card-border);
  border-radius: var(--pico-radius);
  background: var(--pico-card-background);
}

.stat-value {
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  color: var(--pico-muted);
  font-size: 0.85rem;
}

.home-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0;
}

button,
input[type="submit"] {
  font: inherit;
  padding: 0.6rem 1.1rem;
  border: 1px solid var(--pico-primary);
  border-radius: var(--pico-radius);
  color: var(--pico-primary-contrast);
  background: var(--pico-primary);
  cursor: pointer;
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

input[type="text"] {
  font: inherit;
  width: 100%;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--pico-card-border);
  border-radius: var(--pico-radius);
  color: inherit;
  background: var(--pico-background);
}

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

.prompt {
  font-size: 1.5rem;
  line-height: 1.5;
  white-space: pre-line;
  margin-block: 1rem 1.75rem;
}

.prompt + form {
  display: flex;
  gap: 0.75rem;
  align-items: stretch;
  flex-wrap: wrap;
}

.prompt + form input[type="text"] {
  flex: 1 1 12rem;
}

.result.ok {
  border-color: #16a34a;
}

.result.bad {
  border-color: #dc2626;
}

.answer-word {
  font-size: 1.25rem;
}

.phonetic {
  color: var(--pico-muted);
  font-style: italic;
}

.translation,
.definition {
  white-space: pre-line;
}

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

.exchange {
  color: var(--pico-muted);
  font-size: 0.9rem;
}

.actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.25rem;
}

.inline-form {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0;
}

button.secondary {
  color: var(--pico-primary);
  background: transparent;
}

a.button-link {
  display: inline-block;
  padding: 0.6rem 1.1rem;
  border: 1px solid var(--pico-primary);
  border-radius: var(--pico-radius);
  text-decoration: none;
}

.mark-status {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.9rem;
}

.mark-status.ok {
  color: #16a34a;
}

.notice {
  border-color: var(--pico-primary);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-nav {
  display: flex;
  gap: 1rem;
}

.site-nav a {
  color: var(--pico-muted);
  font-size: 0.95rem;
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--pico-primary);
}

.add-form {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.add-form input[type="text"] {
  flex: 1 1 14rem;
}

.form-error {
  color: #dc2626;
  margin-top: 0.75rem;
}

.suggestions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.75rem;
}

button.small {
  padding: 0.35rem 0.7rem;
  font-size: 0.85rem;
}

.word-list {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
}

.word-item {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1rem;
  border-bottom: 1px solid var(--pico-card-border);
}

.word-item:last-child {
  border-bottom: none;
}

.word-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.word-actions form {
  margin: 0;
}

.word-main p {
  margin: 0 0 0.25rem;
}

.word-translation {
  white-space: pre-line;
}

.pagination {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-block: 1.5rem;
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
  }

  .word-item {
    flex-direction: column;
  }

  .word-actions {
    align-self: flex-end;
  }

  .prompt {
    font-size: 1.25rem;
  }
}