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

:root {
  --primary-color: #3498db;
  --secondary-color: #061017;
  --secondary-color-op: rgba(17, 17, 18, 0.581);
  --text-color: #ffffff;
  --text-color-dark: #2c3e50;
  --background-color-light: #f4f4f4;
  --background-color-grey: #dadada;
  --alert-color: #f9522d;
  --success-color: #17612c;
}

body {
  font-family: Arial, sans-serif;
  background-color: var(--background-color-light);
  font-size: 16px;
}

.main {
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 50px;
  padding: 40px;
  width: 100%;
  max-width: 1920px;
  min-height: calc(100vh - 90px);
}

h1,
h2,
h3,
h4 {
  color: var(--text-color-dark);
  border-bottom: 1px solid var(--text-color-dark);
  padding: 10px;
  margin: 2px;
}

.h1 {
  font-size: 2rem;
}

h1 {
  display: inline-block;
  border-bottom: 3px solid var(--text-color-dark);
  padding-bottom: 10px;
  max-width: fit-content;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.section {
  display: flex;
  justify-content: center;
  flex-direction: column;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 40px;
  text-align: center;
  width: 750px;
  background-color: var(--background-color-grey);
  border-radius: 15px;
  margin: 10px;
}

.input {
  margin: 15px;
  padding: 5px 10px;
}

.input:focus-visible {
  outline: none;
}

.btn {
  background-color: var(--primary-color);
  color: var(--text-color);
  border-radius: 10px;
  border: 2px solid var(--primary-color);
  cursor: pointer;
  margin: 5px;
  transition: all 0.3s ease-in;
}

.btn:hover {
  background-color: var(--secondary-color);
  color: var(--text-color);
  border: 2px solid var(--secondary-color);
  box-shadow: 5px 5px 2px var(--secondary-color-op);
}

.input_group,
.info_group {
  margin: 20px 0;
  display: flex;
  justify-content: center;
  flex-direction: column;
  align-items: center;
}

.label {
  font-weight: bold;
  font-size: 1.1rem;
}

.add_btn {
  width: 100px;
  height: 25px;
}

.delete_btn {
  width: 75px;
  height: 20px;
}

.city_list {
  list-style: none;
  width: 300px;
}

.list_item {
  margin: 5px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.list_num {
  margin: 5px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.city_output,
.number_output {
  color: var(--primary-color);
}

span {
  color: var(--text-color-dark);
}

.alert {
  color: var(--alert-color);
}

.success {
  color: var(--success-color);
}