* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Inter", system-ui, sans-serif;
}

body {
  background: #0f172a;
  display: flex;
  justify-content: center;
  padding: 80px 20px;
  color: #e2e8f0;
}

.container {
  background: #1e293b;
  width: 100%;
  max-width: 500px;
  padding: 35px;
  border-radius: 20px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

h1 {
  font-size: 26px;
  font-weight: 600;
  margin-bottom: 8px;
}

#task-counter {
  font-size: 14px;
  color: #94a3b8;
  margin-bottom: 20px;
}

form {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

input {
  flex: 1;
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid #334155;
  background: #0f172a;
  color: white;
  outline: none;
  transition: 0.2s ease;
}

input:focus {
  border-color: #6366f1;
}

button {
  padding: 10px 16px;
  border-radius: 12px;
  border: none;
  background: #6366f1;
  color: white;
  cursor: pointer;
  transition: 0.2s ease;
}

button:hover {
  background: #4f46e5;
}

#search-input {
  margin-bottom: 20px;
}

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

#task-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px;
  border-radius: 12px;
  background: #0f172a;
  margin-bottom: 10px;
  transition: 0.2s ease;
  animation: fadeIn 0.3s ease;
}

#task-list li:hover {
  background: #1e293b;
}

.task-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.checkbox {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid #6366f1;
  cursor: pointer;
  transition: 0.2s ease;
}

.completed .checkbox {
  background: #6366f1;
}

.completed span {
  text-decoration: line-through;
  opacity: 0.5;
}

.delete-btn {
  background: transparent;
  border: none;
  color: #ef4444;
  cursor: pointer;
  font-size: 14px;
  opacity: 0;
  transition: 0.2s ease;
}

#task-list li:hover .delete-btn {
  opacity: 1;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: translateY(0); }
}