/* ── Reset & base ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #ffffff;
  --bg-subtle: #f4f4f1;
  --border: #d0d0ca;
  --border-focus: #808078;
  --text-primary: #080807;
  --text-secondary: #2e2e2a;
  --text-muted: #56564f;
  --accent: #111110;
  --accent-hover: #2e2e2a;
  --tag-bg: #e8e8e3;
  --tag-text: #222220;
  --radius: 8px;
  --font: 'Georgia', 'Times New Roman', serif;
  --font-ui: system-ui, -apple-system, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f0d;
    --bg-subtle: #1a1a17;
    --border: #383832;
    --border-focus: #6e6e66;
    --text-primary: #f5f5ef;
    --text-secondary: #c8c8c0;
    --text-muted: #909088;
    --accent: #f0f0ea;
    --accent-hover: #d0d0c8;
    --tag-bg: #272720;
    --tag-text: #d0d0c8;
  }
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-ui);
  min-height: 100vh;
  padding: 0 1rem;
  display: flex;
  flex-direction: column;
}

/* ── Layout ── */
main {
  max-width: 680px;
  margin: 0 auto;
  padding: 4rem 0 6rem;
}

/* ── Header ── */
header {
  margin-bottom: 3rem;
}

h1 {
  font-family: var(--font);
  font-size: 2.25rem;
  font-weight: normal;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.subtitle {
  font-size: 0.9375rem;
  color: var(--text-muted);
}

/* ── Search ── */
.search-section {
  margin-bottom: 2.5rem;
}

.input-row {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

input[type="text"] {
  flex: 1;
  height: 44px;
  padding: 0 1rem;
  font-size: 1rem;
  font-family: var(--font-ui);
  background: var(--bg);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  outline: none;
  transition: border-color 0.15s;
  letter-spacing: 0.04em;
}

input[type="text"]:focus {
  border-color: var(--border-focus);
}

input[type="text"]::placeholder {
  color: var(--text-muted);
  letter-spacing: 0;
}

button#find-btn {
  height: 44px;
  padding: 0 1.25rem;
  font-size: 0.9375rem;
  font-family: var(--font-ui);
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}

button#find-btn:hover {
  background: var(--accent-hover);
}

button#find-btn:active {
  transform: scale(0.98);
}

/* ── Options ── */
.options-row {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  width: 14px;
  height: 14px;
  cursor: pointer;
  accent-color: var(--text-primary);
}

/* ── Status ── */
.status-section {
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ── Results ── */
.results-section {
  animation: fadeIn 0.2s ease;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

/* ── Length filter bar ── */
.length-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.filter-btn {
  height: 28px;
  padding: 0 0.625rem;
  font-size: 0.8125rem;
  font-family: var(--font-ui);
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: 4px;
  cursor: pointer;
  transition: color 0.12s, border-color 0.12s, background 0.12s;
}

.filter-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-focus);
}

.filter-btn.active {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

button#clear-btn {
  height: 32px;
  padding: 0 0.875rem;
  font-size: 0.8125rem;
  font-family: var(--font-ui);
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

button#clear-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-focus);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Length group */
.length-group {
  margin-bottom: 2rem;
}

.length-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.word-tag {
  display: inline-block;
  padding: 0.3rem 0.7rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: 4px;
  font-size: 0.9375rem;
  letter-spacing: 0.01em;
  cursor: default;
  transition: background 0.1s;
}

.word-tag:hover {
  background: var(--border);
}

/* ── Footer ── */
footer {
  margin-top: auto;
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}

footer a:hover {
  color: var(--text-primary);
}

/* ── Utility ── */
.hidden {
  display: none;
}

/* ── Mobile ── */
@media (max-width: 480px) {
  main {
    padding: 2rem 0 4rem;
  }

  header {
    margin-bottom: 2rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  button#clear-btn {
    height: 44px;
    padding: 0 1.25rem;
  }
}