* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background: #121212;
  color: #e0e0e0;

  display: flex;
  justify-content: center;
  align-items: center;

  height: 100vh;
  margin: 0;
}

.container {
  background: #1e1e1e;
  padding: 25px;
  border-radius: 12px;
  width: 360px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

h1 {
  text-align: center;
}

.input-group {
  display: flex;
  gap: 5px;
}

input {
  padding: 8px;
  border-radius: 6px;
  border: 1px solid #444;
  background: #2a2a2a;
  color: white;
}

#task-input { flex: 2; }
#due-date { flex: 1; }

#add-btn {
  margin-top: 10px;
  width: 100%;
  padding: 8px;
  border: none;
  border-radius: 6px;
  background: #00c853;
  cursor: pointer;
}

.filters {
  display: flex;
  margin-top: 10px;
}

.filters button {
  flex: 1;
  margin: 2px;
  padding: 6px;
  border: none;
  border-radius: 6px;
  background: #333;
  color: white;
  cursor: pointer;
}

.filters .active {
  background: #00c853;
  color: black;
}

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

li {
  display: flex;
  align-items: center;
  gap: 10px;

  background: #2a2a2a;
  padding: 10px;
  border-radius: 6px;
  margin-top: 10px;

  transition: 0.2s;
}

li:hover {
  background: #333;
}

li span {
  flex: 1;
  word-break: break-word;
}

li small {
  font-size: 12px;
  opacity: 0.7;
}

li button {
  background: none;
  border: none;
  color: #ff5252;
  cursor: pointer;
}

.completed {
  text-decoration: line-through;
  color: #999;
}

/* overdue */
.overdue {
  background: #3a1a1a;
}