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

:root {
  --bg: #0b0b0b;
  --card: #111;
  --border: #1f1f1f;
  --text: #ffffff;
  --muted: #aaaaaa;
  --accent: #caec04;
}

body {
  font-family: 'Poppins', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* NAV */
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
}

.logo {
  font-weight: 600;
}

.nav-btn {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 6px;
  text-decoration: none;
  color: var(--text);
}

/* HERO */
.hero {
  text-align: center;
  padding: 80px 20px;
}

.hero h1 span {
  color: var(--accent);
}

.hero p {
  margin-top: 10px;
  color: var(--muted);
}

.hero-actions {
  margin-top: 25px;
  display: flex;
  gap: 15px;
  justify-content: center;
}

.btn {
  padding: 12px 20px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
}

.primary {
  background: var(--accent);
  color: #000;
}

.secondary {
  border: 1px solid var(--border);
  color: var(--text);
}

/* FEATURES */
.features {
  display: grid;
  gap: 20px;
  padding: 40px 20px;
}

.feature-card {
  background: var(--card);
  padding: 20px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

/* PREVIEW */
.preview {
  padding: 40px 20px;
  display: flex;
  justify-content: center;
}

.preview-box {
  background: var(--card);
  width: 100%;
  max-width: 400px;
  padding: 20px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.preview-header {
  height: 20px;
  background: var(--border);
  border-radius: 6px;
  margin-bottom: 15px;
}

.preview-task {
  height: 14px;
  background: var(--border);
  border-radius: 6px;
  margin-bottom: 10px;
}

/* CTA */
.cta {
  text-align: center;
  padding: 60px 20px;
}

.footer {
  text-align: center;
  padding: 20px;
  color: var(--muted);
}

/* APP */
.app-container {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  background: var(--card);
  padding: 20px;
  width: 220px;
  display: none;
}

.main {
  flex: 1;
  padding: 20px;
}

.topbar {
  margin-bottom: 20px;
}

.task-input {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.task-input input {
  flex: 1;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
}

.task-input button {
  padding: 12px 16px;
  border-radius: 8px;
  background: var(--accent);
  border: none;
  font-weight: 600;
  cursor: pointer;
}

.task-list {
  list-style: none;
}

.task {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--card);
  padding: 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  margin-bottom: 10px;
}

.task span {
  flex: 1;
}

.delete {
  background: none;
  border: none;
  color: var(--muted);
  cursor: pointer;
}

.task.completed span {
  text-decoration: line-through;
  color: var(--muted);
}

/* DESKTOP */
@media (min-width: 768px) {
  .sidebar {
    display: block;
  }
}