:root {
  --Bright-Blue: hsl(220, 98%, 61%);
  --Check-Background: hsl(192, 100%, 67%), hsl(280, 87%, 65%);
  /* Light Theme */
  --Very-Light-Gray: hsl(0, 0%, 98%);
  --Very-Light-Grayish-Blue: hsl(236, 33%, 92%);
  --Light-Grayish-Blue-l: hsl(233, 11%, 84%);
  --Dark-Grayish-Blue-l: hsl(236, 9%, 61%);
  --Very-Dark-Grayish-Blue-l: hsl(235, 19%, 35%);
  /* Dark Theme */
  --Very-Dark-Blue: hsl(235, 21%, 11%);
  --Very-Dark-Desaturated-Blue: hsl(235, 24%, 19%);
  --Light-Grayish-Blue-d: hsl(234, 39%, 85%);
  --Light-Grayish-Blue-hover: hsl(236, 33%, 92%);
  --Dark-Grayish-Blue: hsl(234, 11%, 52%);
  --Very-Dark-Grayish-Blue-d: hsl(233, 14%, 35%);
  --Very-Dark-Grayish-Blue: hsl(237, 14%, 26%);
}

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
body {
  font-size: 18px;
  font-family: "Josefin Sans", sans-serif;
  background-image: url(./images/bg-desktop-light.jpg);
  background-repeat: no-repeat;
  background-color: var(--Very-Light-Gray);
  background-position-x: center;
}
.dark {
  background-image: url(./images/bg-desktop-dark.jpg);
  background-color: var(--Very-Dark-Blue);
}
main {
  width: 32rem;
  margin: 4rem auto;
  padding: 0 1.5rem;
  max-width: 100%;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header h1 {
  color: white;
  letter-spacing: 15px;
}
header .img-mode {
  cursor: pointer;
}
header .img-mode img.sun {
  display: none;
}
.dark .img-mode img.sun {
  display: block;
}
.dark .img-mode img.moon {
  display: none;
}
label {
  position: relative;
}
label span {
  border: 2px solid var(--Very-Light-Grayish-Blue);
  margin: 42px 15px;
  border-radius: 50%;
  width: 22px;
  height: 22px;
  position: absolute;
}
.dark label span {
  border-color: var(--Very-Dark-Grayish-Blue);
}
label input {
  border: none;
  padding: 15px;
  width: 100%;
  border-radius: 4px;
  font-size: 18px;
  font-family: "Josefin Sans", sans-serif;
  margin: 30px 0 20px;
  padding-left: 50px;
  caret-color: var(--Bright-Blue);
}
.dark label input {
  background-color: var(--Very-Dark-Desaturated-Blue);
  color: white;
}
label input:focus {
  outline: none;
}

section {
  background-color: white;
  width: 100%;
  border-radius: 4px;
  box-shadow: 0px 10px 30px hsl(236deg 9% 61% / 20%);
}
.dark section {
  background-color: var(--Very-Dark-Desaturated-Blue);
  box-shadow: 0px 10px 30px hsl(0deg 0% 0% / 30%);
}
section .item {
  border-bottom: 1px solid var(--Very-Light-Grayish-Blue);
  padding: 15px;
  display: flex;
  align-items: end;
  color: var(--Very-Dark-Grayish-Blue-l);
}
.dark section .item {
  border-color: var(--Very-Dark-Grayish-Blue);
  color: var(--Light-Grayish-Blue-d);
}
section .item span {
  border: 2px solid var(--Very-Light-Grayish-Blue);
  margin-right: 15px;
  border-radius: 50%;
  width: 22px;
  height: 22px;
}
.dark section .item span {
  border-color: var(--Very-Dark-Grayish-Blue);
}
section .item span:hover {
  background-image: linear-gradient(white, white), linear-gradient(135deg, var(--Check-Background));
  border: 2px solid transparent;
  background-origin: border-box;
  background-clip: padding-box, border-box;
}
.dark section .item span:hover {
  background-image: linear-gradient(var(--Very-Dark-Desaturated-Blue), var(--Very-Dark-Desaturated-Blue)), linear-gradient(135deg, var(--Check-Background));
}
section .item.checked span {
  background-image: linear-gradient(135deg, var(--Check-Background));
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}
section .item.checked span::after {
  content: url(./images/icon-check.svg);
  position: absolute;
}
.dark section .item.checked p {
  color: var(--Very-Dark-Grayish-Blue-d);
}
section .item.checked p {
  color: var(--Light-Grayish-Blue-l);
  text-decoration: line-through;
}
section .item img {
  margin-left: auto;
  display: none;
}
section .item:hover img {
  display: block;
}
section .item span, section .item p, section .item img {
  cursor: pointer;
}

section .control {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px;
  font-size: 14px;
  color: var(--Dark-Grayish-Blue-l);
  position: relative;
}
section .control .filter {
  display: flex;
  gap: 15px;
}
section .control .filter span, section .control .clear {
  cursor: pointer;
  font-weight: 700;
}
section .control .filter span:hover, section .control .clear:hover {
  color: var(--Dark-Grayish-Blue);
}
.dark section .control .filter span:hover, .dark section .control .clear:hover {
  color: var(--Light-Grayish-Blue-hover);
}
section .control .filter span.active {
  color: var(--Bright-Blue);
}
main > p {
  color: var(--Dark-Grayish-Blue-l);
  text-align: center;
  padding-top: 4rem;
  font-size: 14px;
}

footer {
  font-size: 12px;
  width: max-content;
  position: absolute;
  bottom: 10px;
  right: 50%;
  transform: translate(50%);
  opacity: .7;
}
.dark footer {
  color: var(--Light-Grayish-Blue-d);
}
footer a {
  color: var(--Bright-Blue);
  text-decoration: none;
}

@media (max-width: 500px) {
  body {
    font-size: 16px;
  }
  section .control .filter {
    position: absolute;
    bottom: -60px;
    right: 0;
    background: white;
    padding: 15px;
    width: 100%;
    border-radius: 4px;
    box-shadow: 0px 10px 30px hsl(236deg 9% 61% / 20%);
    justify-content: center;
  }
  .dark section .control .filter {
    background-color: var(--Very-Dark-Desaturated-Blue);
    box-shadow: 0px 10px 30px hsl(0deg 0% 0% / 30%);  
  }
  main > p {
    padding-top: 6rem;
  }
}