/* Dark Mode - Custom Property Variables*/
:root {
  --bg: rgb(18, 18, 18);
  --card: rgb(36, 36, 36);
  --text: rgb(230, 230, 230);
  --accent: rgb(165, 150, 230);
  --danger: rgb(255, 110, 110);
  --border: rgb(68, 68, 68);
  --shadow: rgba(255, 255, 255, 0.25);
}

/* Light Mode - Custom Property Variables*/
body.light {
  --bg: rgb(230, 230, 230);
  --card: rgb(255, 255, 255);
  --text: rgb(45, 45, 45);
  --accent: rgb(91, 85, 125);
  --danger: rgb(217, 48, 37);
  --border: rgb(187, 187, 187);
  --shadow: rgba(0, 0, 0, 0.25);
}

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

body {
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: color 0.25s;
}

/* Content Container */
.container {
  max-width: 480px;
  margin: 48px auto;
  padding: 0 16px 0 16px;
}

/* Heading */
h1 {
  margin-bottom: 20px;
  font-size: 28px;
  font-weight: bolder;
  text-shadow: 4px 4px 6px var(--shadow);
}

#theme-toggle {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  margin-bottom: 20px;
  transition: transform 1s ease;
  transform-origin: center center;
  text-shadow: 2px 2px 5px var(--shadow);
}

#theme-toggle.flipped {
  transform: rotate(180deg);
  text-shadow: -3px -3px 5px var(--shadow);
}

/* Form */
form {
  display: flex;
  gap: 8px;
  margin: 24px 0 24px 0;
}

input[type="text"] {
  padding: 8px 12px 8px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 16px;
  background: var(--surface);
  color: var(--text);
  box-shadow: 3px 3px 5px var(--shadow);
}

button[type="submit"] {
  padding: 8px 12px 8px 12px;
  border: none;
  border-radius: 4px;
  background: var(--accent);
  color: white;
  font-size: 16px;
  cursor: pointer;
  transition: filter 0.5s;
  box-shadow: 3px 3px 5px var(--shadow);
}

button[type="submit"]:hover {
  filter: brightness(1.2);
}

/* Tasks */
#item-list {
  list-style: none;
}

#item-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px 10px 12px;
  margin-bottom: 8px;
  border-radius: 4px;
  background: var(--surface);
  box-shadow: 3px 3px 5px var(--shadow);
}

#item-list .left {
  display: flex;
  align-items: center;
  gap: 8px;
}

input[type="checkbox"] {
  transform: scale(1.15);
  cursor: pointer;
}

span.done {
  text-decoration: line-through;
  color: var(--border);
}

.delete-btn {
  background: transparent;
  border: none;
  color: var(--danger);
  font-size: 16px;
  cursor: pointer;
}

.delete-btn:hover {
  color: var(--text);
}