/* =========================================================
   BASE STYLES
   Minimal starter — reset, typography, background, variables.
   ========================================================= */

/* =========================
   1. VARIABLES
   ========================= */

:root {
  /* === Colors === */
  --color-bg: #e4e7ff;
  --color-bg-sec: #ffffff;

  --color-text: #0a0e27;
  --color-accent: #3366ff;
  --color-border: #e0e0e0;

  /* === Gradient === */
  --gradient-1: #788aff;
  --gradient-2: #ff8f83;

  /* === Spacing === */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem; /* 16 */
  --space-lg: 1.5rem; /* 24 */
  --space-xl: 2rem; /* 32 */
  --space-2xl: 3rem; /* 48 */
  --space-3xl: 5rem; /* 80 */
  --space-4xl: 6rem; /* 96 */

  /* === Font Sizes === */
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.25rem;
  --text-xl: 1.75rem;

  /* === Transitions === */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;

  /* === Effects === */
  --shadow: 0px 0px 16px 0px rgba(47, 29, 61, 0.7);
  --shadow-dark: 0px 0px 16px 0px rgb(8, 0, 14);
}

/* =========================
   2. RESET
   ========================= */

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

body {
  font-family: "Poppins", sans-serif;
}

/* =========================
   3. TYPOGRAPHY
   ========================= */

h1,
h2,
h3,
h4 {
  line-height: 1.2;
  font-weight: 700;
}

h1 {
  font-size: clamp(1.5rem, 5vw, 2.5rem);
}

h2 {
  font-size: clamp(1.25rem, 4vw, 2rem);
}

h3,
h4 {
  font-size: clamp(1.1rem, 3vw, 1.5rem);
}

p {
  font-size: var(--text-base);
  color: var(--color-text);
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: var(--transition-fast);
}

a:hover {
  text-decoration: underline;
}

/* =========================
   COMPONENTS
   ========================= */

.container {
  width: 100%;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2));
  padding: var(--space-md);
  /* text-align: center; */
}

.todo-app {
  width: 100%;
  max-width: 540px;
  background: var(--color-bg);
  margin: var(--space-4xl) auto var(--space-lg);
  padding: var(--space-2xl) var(--text-xl) var(--space-3xl);
  border-radius: var(--space-md);
  /* text-align: center; */
  transition: var(--transition-normal);
}
.todo-app:hover {
  box-shadow: var(--shadow);
}
.todo-app h2 {
  color: var(--color-text);
  display: flex;
  align-items: center;
  margin-bottom: var(--space-lg);
}

.todo-app h2 img {
  width: 30px;
  margin-left: var(--space-md);
}

.row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-bg-sec);
  border-radius: var(--space-xl);
  padding-left: var(--space-md);
  margin-bottom: var(--space-lg);
}

input {
  flex: 1;
  border: none;
  outline: none;
  background-color: transparent;
  padding: var(--space-md);
}

button {
  border: none;
  outline: none;
  padding: var(--space-md) var(--space-2xl);
  border-radius: var(--space-xl);
  background: #ff5945;
  color: var(--color-bg-sec);
  font-size: var(--text-base);
  cursor: pointer;
}

ul li {
  list-style: none;
  font-size: var(--text-base);
  padding: var(--space-md) var(--space-sm) var(--space-md) var(--space-2xl);
  user-select: none;
  cursor: pointer;
  position: relative;
}
ul li::before {
  content: "";
  position: absolute;
  height: 28px;
  width: 28px;
  border-radius: 50%;
  background-image: url(media/unchecked.png);
  background-size: cover;
  background-position: center;
  top: 12px;
  left: 8px;
}
ul li.checked {
  color: #555;
  text-decoration: line-through;
}
ul li.checked::before {
  background-image: url(media/checked.png);
}
ul li span {
  position: absolute;
  right: 0;
  top: 5px;
  width: 40px;
  height: 40px;
  font-size: 22px;
  color: #555;
  line-height: 40px;
  text-align: center;
  border-radius: 50%;
}
ul li span:hover {
  background: var(--color-bg-sec);
}

.error {
  text-align: left;
  margin-left: var(--space-sm);
  margin-top: var(--space-sm);
  font-size: var(--text-sm);
  display: none;
}