:root {
  --bg: #0a0a0f;
  --surface: #12121a;
  --border: #1e1e2e;
  --text: #e0e0e8;
  --text-muted: #8888a0;
  --accent: #6c5ce7;
  --accent-light: #a29bfe;
  --code-bg: #1a1a2e;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--accent-light); text-decoration: none; }
a:hover { text-decoration: underline; }

nav {
  position: sticky; top: 0; z-index: 10;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 960px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 1rem 2rem;
}
.logo {
  font-size: 1.4rem; font-weight: 800;
  color: var(--accent-light); letter-spacing: 2px;
}
.nav-links { display: flex; gap: 1.5rem; }
.nav-links a { color: var(--text-muted); font-size: 0.95rem; }
.nav-links a.active, .nav-links a:hover { color: var(--accent-light); }

main { max-width: 960px; margin: 0 auto; padding: 2rem; }

.hero { text-align: center; padding: 4rem 0 3rem; }
.hero h1 {
  font-size: 3rem; font-weight: 800;
  background: linear-gradient(135deg, var(--accent-light), #fd79a8);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.subtitle {
  margin-top: 1rem; font-size: 1.2rem; color: var(--text-muted);
  max-width: 600px; margin-left: auto; margin-right: auto;
}
.badges {
  margin-top: 1.5rem; display: flex; gap: 0.75rem; justify-content: center;
}
.badge {
  padding: 0.35rem 0.9rem; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border);
  font-size: 0.8rem; color: var(--accent-light);
}

.features, .feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem; margin-top: 2rem;
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; padding: 1.5rem;
  transition: border-color 0.2s;
}
.card:hover { border-color: var(--accent); }
.card h3 { color: var(--accent-light); margin-bottom: 0.5rem; font-size: 1.05rem; }
.card p { color: var(--text-muted); font-size: 0.9rem; }

.content { padding: 2rem 0; }
.content h1 {
  font-size: 2.2rem; font-weight: 800; margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-light), #fd79a8);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.content h2 { font-size: 1.3rem; margin: 2rem 0 0.75rem; color: var(--accent-light); }
.content p { color: var(--text-muted); margin-bottom: 1rem; }
.content ul { margin: 0.5rem 0 1rem 1.5rem; color: var(--text-muted); }
.content li { margin-bottom: 0.5rem; }
.content li strong { color: var(--text); }

code {
  font-family: "SF Mono", "Fira Code", monospace;
  background: var(--code-bg); padding: 0.15rem 0.4rem;
  border-radius: 4px; font-size: 0.85em; color: var(--accent-light);
}
pre {
  background: var(--code-bg); border: 1px solid var(--border);
  border-radius: 8px; padding: 1.25rem; overflow-x: auto;
  margin: 0.75rem 0 1.5rem;
}
pre code { background: none; padding: 0; font-size: 0.85rem; color: var(--text); }

table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
th, td {
  text-align: left; padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
}
th { color: var(--accent-light); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1px; }
td { color: var(--text-muted); font-size: 0.9rem; }
td code { font-size: 0.8rem; }

/* Stack diagram */
.demo-stack {
  display: flex; align-items: center; justify-content: center;
  gap: 1rem; margin: 1.5rem 0 2rem; flex-wrap: wrap;
}
.stack-item {
  text-align: center;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 10px; padding: 1rem 1.5rem;
  min-width: 100px;
}
.stack-icon {
  font-size: 1.1rem; font-weight: 700; color: var(--accent-light);
}
.stack-label {
  font-size: 0.75rem; color: var(--text-muted); margin-top: 0.25rem;
}
.stack-arrow {
  color: var(--text-muted); font-size: 1.2rem;
}

/* Todo app */
.todo-app {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin-bottom: 1rem;
}
.todo-input-row {
  display: flex; border-bottom: 1px solid var(--border);
}
.todo-input-row input {
  flex: 1; padding: 0.9rem 1.25rem;
  background: transparent; border: none; outline: none;
  color: var(--text); font-size: 0.95rem;
  font-family: inherit;
}
.todo-input-row input::placeholder { color: #444460; }
.todo-input-row button {
  padding: 0.9rem 1.5rem; background: var(--accent); color: #fff;
  border: none; font-weight: 600; cursor: pointer; font-size: 0.9rem;
  transition: background 0.2s;
}
.todo-input-row button:hover { background: var(--accent-light); }
.todo-list { min-height: 60px; }
.todo-loading, .todo-empty {
  padding: 2rem; text-align: center; color: var(--text-muted); font-size: 0.9rem;
}
.todo-item {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--border);
  transition: background 0.15s;
}
.todo-item:last-child { border-bottom: none; }
.todo-item:hover { background: rgba(108, 92, 231, 0.05); }
.todo-item.done .todo-text {
  text-decoration: line-through; color: var(--text-muted);
}
.todo-check {
  background: none; border: none; cursor: pointer;
  font-size: 1.2rem; color: var(--accent-light); line-height: 1;
  padding: 0;
}
.todo-text { flex: 1; font-size: 0.95rem; }
.todo-del {
  background: none; border: none; cursor: pointer;
  font-size: 1.2rem; color: #555; line-height: 1; padding: 0;
  opacity: 0; transition: opacity 0.15s;
}
.todo-item:hover .todo-del { opacity: 1; }
.todo-del:hover { color: #ff6b6b; }
.todo-footer {
  padding: 0.6rem 1.25rem;
  font-size: 0.8rem; color: var(--text-muted);
  border-top: 1px solid var(--border);
}
.todo-footer:empty { display: none; }

footer {
  text-align: center; padding: 3rem 2rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted); font-size: 0.85rem;
}

/* Demo grid */
.demo-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 1.5rem; margin-top: 1.5rem;
}
.demo-panel {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; padding: 1.25rem;
}
.demo-panel h2 {
  font-size: 1.1rem; color: var(--accent-light); margin: 0 0 0.75rem;
}
.demo-panel .demo-stack { margin: 0.75rem 0; }
.demo-panel .todo-app { margin: 0.75rem 0; }
.highlight {
  background: var(--accent); border-color: var(--accent);
}
.highlight .stack-icon { color: #fff; }
.highlight .stack-label { color: rgba(255,255,255,0.7); }
details { margin-top: 0.75rem; }
summary {
  cursor: pointer; color: var(--text-muted); font-size: 0.85rem;
  user-select: none;
}
summary:hover { color: var(--accent-light); }
details pre { margin-top: 0.5rem; }

@media (max-width: 640px) {
  .hero h1 { font-size: 2rem; }
  .subtitle { font-size: 1rem; }
  main { padding: 1rem; }
  .demo-grid { grid-template-columns: 1fr; }
}