:root {
  --bg: #f4f7f2;
  --surface: #ffffff;
  --text: #1f2d1a;
  --muted: #4f5f4a;
  --accent: #2f6b3a;
  --accent-dark: #24542e;
  --border: #c9d4c3;
  --focus: #1a5cff;
  --success: #1f6b3a;
  --error: #8b2e2e;
}

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

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--accent-dark);
}

a:hover,
a:focus-visible {
  text-decoration-thickness: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: 0.75rem 1rem;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-inner,
main,
.site-footer {
  max-width: 900px;
  margin: 0 auto;
  padding: 1rem 1.25rem;
}

.logo {
  margin: 0;
  font-size: 1.5rem;
}

.tagline {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
}

.site-nav a {
  display: inline-block;
  padding: 0.35rem 0.5rem;
  font-weight: 600;
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  color: var(--text);
  border-bottom: 3px solid var(--accent);
}

main h1 {
  margin-top: 0;
  font-size: 1.75rem;
}

.intro {
  font-size: 1.05rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.1rem;
  border: 2px solid var(--accent);
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}

.btn:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
}

.btn-secondary {
  background: var(--surface);
  color: var(--accent-dark);
}

.btn-secondary:hover {
  background: #eef3eb;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn:disabled:hover {
  background: var(--accent);
  border-color: var(--accent);
}

.btn-secondary:disabled:hover {
  background: var(--surface);
  border-color: var(--border);
}

.filters {
  display: grid;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 600px) {
  .filters {
    grid-template-columns: 2fr 1fr;
  }
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

input,
select {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border: 2px solid var(--border);
  border-radius: 6px;
  font: inherit;
  background: var(--surface);
  color: var(--text);
}

input:focus-visible,
select:focus-visible,
button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.bird-list {
  display: grid;
  gap: 1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.bird-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.1rem;
}

.bird-card h2 {
  margin: 0 0 0.25rem;
  font-size: 1.25rem;
}

.latin {
  margin: 0;
  color: var(--muted);
  font-style: italic;
}

.habitat {
  display: inline-block;
  margin: 0.5rem 0;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  background: #e8f0e4;
  font-size: 0.85rem;
}

.description {
  margin: 0.5rem 0 1rem;
}

.player-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.player-status {
  min-height: 1.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.empty-message {
  padding: 1rem;
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: 8px;
}

.quiz-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
}

.quiz-progress {
  color: var(--muted);
  margin-bottom: 1rem;
}

.quiz-options {
  display: grid;
  gap: 0.5rem;
  margin: 1rem 0;
}

.quiz-option {
  text-align: left;
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  font: inherit;
  cursor: pointer;
}

.quiz-option:hover {
  border-color: var(--accent);
}

.quiz-option:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.quiz-option:disabled {
  cursor: not-allowed;
}

.quiz-option.correct {
  border-color: var(--success);
  background: #e8f4ea;
}

.quiz-option.wrong {
  border-color: var(--error);
  background: #f9eaea;
}

.quiz-feedback {
  min-height: 1.5rem;
  font-weight: 600;
}

.quiz-feedback.success {
  color: var(--success);
}

.quiz-feedback.error {
  color: var(--error);
}

.quiz-result {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.site-footer {
  margin-top: 2rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}