:root {
  --bg: #0e1116;
  --fg: #e6edf3;
  --muted: #8b949e;
  --accent: #58a6ff;
  --good: #3fb950;
  --bad: #f85149;
  --panel: #161b22;
  --panel-2: #1c232c;
  --border: #30363d;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  background: var(--bg); color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 16px; line-height: 1.55;
}

main {
  max-width: 820px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

header h1 {
  font-size: 1.85rem;
  margin: 0 0 0.25rem;
  letter-spacing: -0.01em;
}

.lede {
  margin: 0 0 1.25rem;
  color: var(--muted);
  max-width: 60ch;
}

.lede em { color: var(--fg); font-style: normal; font-weight: 500; }

.actions {
  margin: 0 0 2rem;
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--fg);
  border-radius: 6px;
  font-size: 0.9rem;
  text-decoration: none;
}

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

.btn.primary {
  background: var(--accent);
  color: #0d1117;
  border-color: var(--accent);
  font-weight: 500;
}

.demo, .info {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
}

.demo h2, .info h2 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
}

.hint { color: var(--muted); font-size: 0.92rem; margin: 0 0 1rem; }
.hint code { background: var(--panel-2); padding: 0.1rem 0.35rem; border-radius: 4px; font-size: 0.85em; }

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

.row label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-size: 0.78rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  flex: 1;
  min-width: 280px;
}

input[type="text"] {
  font: inherit;
  font-size: 0.95rem;
  padding: 0.55rem 0.8rem;
  background: var(--panel-2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 6px;
  width: 100%;
}

#textInput { flex: 1; min-width: 200px; }

button {
  font: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.55rem 1.1rem;
  background: var(--accent);
  color: #0d1117;
  border: 1px solid var(--accent);
  border-radius: 6px;
  cursor: pointer;
}

button:hover { filter: brightness(1.1); }

.todo-list {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0;
}

.todo-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 0.5rem 0.25rem;
  border-bottom: 1px solid rgba(48, 54, 61, 0.5);
}

.todo-list li:last-child { border-bottom: none; }

.todo-list input[type="checkbox"] {
  margin-top: 0.25rem;
  accent-color: var(--accent);
  cursor: pointer;
}

.todo-list .text {
  flex: 1;
  word-break: break-word;
}

.todo-list li.done .text {
  text-decoration: line-through;
  color: var(--muted);
}

.todo-list .remove {
  font-size: 1rem;
  background: transparent;
  color: var(--muted);
  border: none;
  cursor: pointer;
  padding: 0 0.25rem;
}

.todo-list .remove:hover { color: var(--bad); }

.empty {
  color: var(--muted);
  text-align: center;
  font-size: 0.92rem;
  padding: 1rem 0;
}

details {
  margin-top: 1rem;
  font-size: 0.88rem;
}

details summary {
  cursor: pointer;
  color: var(--muted);
  user-select: none;
}

details pre {
  margin: 0.5rem 0 0;
  padding: 0.75rem 1rem;
  background: var(--panel-2);
  border-radius: 6px;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.78rem;
  color: var(--accent);
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 280px;
  overflow-y: auto;
}

.info ul {
  margin: 0.4rem 0 0;
  padding-left: 1.25rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.info li { margin: 0.4rem 0; }

.info code {
  background: var(--panel-2);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.85em;
}

footer {
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
}

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