@layer reset {
  /* Use border-box for everything */
  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }

  /* Remove default margins and padding */
  * {
    margin: 0;
    padding: 0;
  }

  /* Core document settings */
  html {
    -webkit-text-size-adjust: none;
    text-size-adjust: none;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    /* Use dynamic viewport for better mobile sizing */
    min-block-size: 100dvb;
  }

  /* Improve media defaults */
  img,
  picture,
  video,
  canvas,
  svg {
    display: block;
    max-width: 100%;
  }

  /* Inherit fonts for form elements */
  input,
  button,
  textarea,
  select {
    font: inherit;
  }

  /* Allow smooth transitions for height: auto */
  :root {
    interpolate-size: allow-keywords;
  }
}

:root {
  color-scheme: light dark;

  /* Typography */
  --font-family-base: 'Nunito Sans', sans-serif;
  --font-size-base: 16px;
  --font-size-sm: 14px;
  --font-size-lg: 20px;
  --font-size-xl: 32px;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 2.5rem;
  --spacing-3xl: 3rem;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.16);

  /* Light mode palette */
  --color-text: hsl(200, 15%, 8%);
  --color-bg: hsl(0, 0%, 99%);
  --color-surface: hsl(0, 0%, 100%);
  --color-border: hsl(0, 0%, 90%);
  --color-input: hsl(0, 0%, 50%);
  --color-muted: hsl(0, 0%, 60%);
  --color-on-surface: hsl(200, 15%, 8%);
  --color-emphasis: hsl(0, 0%, 100%);
  --color-error: hsl(0, 100%, 59%);
  --color-bg-error: hsla(0, 100%, 59%, 0.2);
}

[data-theme='dark'] {
  --color-text: hsl(0, 100%, 100%);
  --color-bg: hsl(207, 26%, 17%);
  --color-surface: hsl(209, 23%, 22%);
  --color-border: rgba(255, 255, 255, 0.12);
  --color-input: hsl(0, 0%, 100%);
  --color-muted: hsla(0, 0%, 100%, 0.7);
  --color-on-surface: hsl(0, 100%, 100%);
  --color-emphasis: hsl(0, 100%, 100%);
}

ul,
li {
  list-style: none;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-3xl);
  color: var(--color-text);
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  width: 100%;
  box-shadow: var(--shadow-sm);
  position: relative;
}

h1 {
  font-size: var(--font-size-lg);
  font-weight: 800;
}

h2 {
  font-size: var(--font-size-base);
}

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

body {
  min-width: 350px;
  color: var(--color-text);
  background-color: var(--color-bg);
  font-size: var(--font-size-base);
  font-family: var(--font-family-base);
}

main {
  padding: 0 var(--spacing-3xl) var(--spacing-2xl);
  transition: padding 300ms ease;
}

.btn {
  height: 40px;
  font-size: var(--font-size-sm);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-input);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);

  &:hover {
    cursor: pointer;
    border-color: var(--color-text);
  }

  &.btn--sm {
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

.back-btn {
  display: inline-block;
  margin: var(--spacing-2xl) 0;
}

button#theme-toggle {
  color: var(--color-text);
  border: transparent;
}

button#shuffle {
  & .shuffling {
    animation: shuffle 0.3s ease-in-out both;
  }
}

select {
  appearance: none;
  -webkit-appearance: none; /* Safari/Chrome */
  -moz-appearance: none;

  &:hover {
    cursor: pointer;
    border-color: var(--color-text);
  }
}

.container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  margin: var(--spacing-2xl) 0;
  gap: var(--spacing-xs);
}

.container__inner {
  place-content: end;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.container__search {
  width: 100%;
  max-width: 400px;
  position: relative;

  & .icon {
    position: absolute;
    top: 50%;
    left: var(--spacing-md);
    transform: translateY(-50%);
    pointer-events: none;
  }

  & input {
    width: 100%;
    padding-left: var(--spacing-3xl);
  }
}

.container__region-select {
  min-width: 200px;
  position: relative;
  display: flex;
  align-items: center;
  padding: 0;

  & select {
    width: 100%;
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
  }

  & .icon {
    position: absolute;
    right: var(--spacing-sm);
    pointer-events: none;
  }
}

.cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-3xl);

  & .card {
    overflow: hidden;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);

    &:hover {
      & .card__details {
        background-color: var(--color-surface);
        transition: background-color 300ms ease;
      }
    }

    & .card__flag {
      background-color: black;

      & img {
        height: 200px;
        width: 100%;
        object-fit: cover;
      }
    }
    & .card__details {
      padding: var(--spacing-md);
      background-color: var(--color-surface);

      & .card__details-title {
        margin-bottom: var(--spacing-sm);
      }
      & .card__details-item {
        margin-bottom: var(--spacing-xs);
        & span {
          font-weight: 600;
          font-size: var(--font-size-sm);
        }
      }
    }
  }
}

.status {
  position: fixed;
  bottom: var(--spacing-md);
  right: var(--spacing-md);
  padding: var(--spacing-xs);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  z-index: 99;

  &.status--error {
    color: var(--color-error);
    background-color: var(--color-bg-error);
  }
}

.suggestions {
  font-style: italic;
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-sm);

  & .suggestions__country {
    text-decoration: underline;
    opacity: 0.8;

    &:hover {
      opacity: 1;
    }
  }
}

.details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: var(--spacing-3xl);

  & .details__flag {
    border: 1px solid var(--color-border);
    width: 100%;

    & img {
      width: 100%;
      max-height: 400px;
      object-fit: cover;
    }
  }

  & .details__info {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3xl);
    padding: var(--spacing-2xl) var(--spacing-3xl);
    font-size: var(--font-size-sm);

    & .details__info-main {
      display: flex;
      flex-direction: column;
      gap: var(--spacing-md);
    }

    & .details__info-name {
      font-size: var(--font-size-xl);
      font-weight: 800;
    }

    & .details__info-list {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: var(--spacing-lg);
      justify-content: space-between;
    }

    & .details__info-border-countries {
      display: flex;
      flex-direction: row;
      align-items: center;
      gap: var(--spacing-sm);

      & .details__info-border-countries-list {
        display: flex;
        flex-direction: row;
        flex-wrap: wrap;
        gap: var(--spacing-sm);

        & .details__info-border-countries-item {
          padding: 0 var(--spacing-sm);
          border: 1px solid var(--color-border);
          border-radius: var(--radius-sm);

          &:hover {
            border-color: var(--color-text);
          }
        }
      }
    }
  }
}

.icon {
  width: 20px;
  height: 20px;
  fill: currentColor;

  &.icon--sm {
    width: 16px;
    height: 16px;
  }
}

.loader {
  width: 100%;
  position: absolute;
  bottom: -2px;
  left: 0;
  padding: 1px;
}
.loader:before {
  content: '';
  position: absolute;
  top: -4px;
  right: -4px;
  bottom: -4px;
  left: -4px;
}
.loader__bar {
  position: absolute;
  top: 0;
  right: 100%;
  bottom: 0;
  left: 0;
  background: var(--color-text);
  width: 500px;
  animation: borealisBar 2s linear infinite;
  transform-origin: left;
}

@keyframes borealisBar {
  0% {
    transform: translateX(0%) scaleX(0);
  }

  10% {
    transform: translateX(0%) scaleX(0.25);
  }

  90% {
    transform: translateX(300%) scaleX(0.25);
  }

  100% {
    transform: translateX(400%) scaleX(0);
  }
}

@keyframes shuffle {
  from {
    transform: rotateX(0deg);
  }
  to {
    transform: rotateX(180deg);
  }
}

/* utilities */
.flex {
  display: flex;
  align-items: center;
}
.gap-xs {
  gap: var(--spacing-xs);
}
.gap-sm {
  gap: var(--spacing-sm);
}
.gap-md {
  gap: var(--spacing-md);
}
.gap-lg {
  gap: var(--spacing-lg);
}
.gap-xl {
  gap: var(--spacing-xl);
}

@media (max-width: 78rem) {
  .cards {
    grid-template-columns: repeat(3, 1fr);
  }

  .details {
    & .details__info {
      & .details__info-border-countries {
        flex-direction: column;
        align-items: flex-start;
      }
    }
  }
}

@media (max-width: 62rem) {
  .cards {
    grid-template-columns: repeat(2, 1fr);
  }

  .details {
    grid-template-columns: 1fr;

    & .details__info {
      padding: 0;
    }
  }
}

@media (max-width: 40rem) {
  .cards {
    grid-template-columns: 1fr;
  }

  .details {
    & .details__info {
      padding: 0;

      & .details__info-list {
        grid-template-columns: 1fr;
        gap: 0;
      }
    }
  }

  .container {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    gap: var(--spacing-md);

    & .container__inner {
      place-content: start;
    }
  }

  .container__search {
    max-width: none;
  }
}