* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f6f8;
  color: #1f2933;
}

.container {
  width: min(700px, 90%);
  margin: 40px auto;
  background: white;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
}

h1,
h2 {
  margin-top: 0;
}

form {
  display: grid;
  gap: 16px;
  margin-bottom: 25px;
}

.form-group {
  display: grid;
  gap: 6px;
}

input {
  padding: 10px;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  font-size: 16px;
}

button {
  padding: 10px 16px;
  border: 0;
  border-radius: 6px;
  cursor: pointer;
  font-size: 15px;
}

form button {
  background: #2563eb;
  color: white;
}

.delete-button {
  background: #dc2626;
  color: white;
}

#items-list {
  list-style: none;
  padding: 0;
}

.item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px;
  margin-bottom: 10px;
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 7px;
}

.message {
  min-height: 24px;
}

.message.error {
  color: #b91c1c;
}

.message.success {
  color: #15803d;
}