@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600&display=swap');

:root {
  --bg: #0e0e10;
  --card: rgba(255, 255, 255, 0.05);
  --primary: #00bfa6;
  --danger: #ff4d6d;
  --text: #f1f1f1;
  --muted: #888;
  --blur: 16px;
}

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

body {
  font-family: 'Inter', sans-serif;
  background: linear-gradient(135deg, #090909, #141414);
  color: var(--text);
  display: flex;
  justify-content: center;
  padding: 40px 16px;
  min-height: 100vh;
}

.app {
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(var(--blur));
  border-radius: 20px;
  padding: 32px 28px;
  width: 100%;
  max-width: 600px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
  transition: all 0.3s ease;
}

h1 {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 28px;
}

.input-section {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

input[type="text"] {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.03);
  color: white;
  font-size: 1rem;
  outline: none;
  transition: border 0.3s ease;
}

input[type="text"]:focus {
  border: 1px solid var(--primary);
}

button {
  background: var(--primary);
  border: none;
  padding: 12px 18px;
  border-radius: 14px;
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

button:hover {
  background: #00e1c1;
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(0, 255, 204, 0.4);
}

.filter-buttons {
  display: flex;
  justify-content: space-between;
  margin-bottom: 20px;
}

.filter-buttons button {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text);
  padding: 8px 14px;
  font-size: 0.9rem;
  border-radius: 10px;
  transition: all 0.3s ease;
}

.filter-buttons .active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 14px 18px;
  border-radius: 16px;
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
}

li:hover {
  background: rgba(255, 255, 255, 0.06);
}

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

.actions button {
  background: var(--danger);
  border: none;
  padding: 6px 10px;
  font-size: 0.8rem;
  border-radius: 10px;
  color: white;
  transition: background 0.3s ease;
}

.actions button:hover {
  background: #ff2d5a;
}

@media (max-width: 500px) {
  .input-section {
    flex-direction: column;
  }

  .filter-buttons {
    flex-direction: column;
    gap: 10px;
  }

  button {
    width: 100%;
  }
}