:root {
  --text: #181818;
  --muted: #5f6670;
  --paper: #fff;
  --hero: #202020;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: "Open Sans", "Helvetica Neue", Arial, "Noto Sans SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
}

a {
  color: inherit;
  text-decoration: none;
}

.post-header {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 20;
  color: #fff;
  transition: background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.post-header.is-solid {
  background: #fff;
  color: #171717;
  box-shadow: 0 7px 18px rgba(0, 0, 0, 0.08);
}

.post-nav {
  display: flex;
  width: min(842px, calc(100% - 48px));
  height: 84px;
  align-items: center;
  justify-content: space-between;
  margin: 0 auto;
  transition: height 180ms ease;
}

.post-header.is-solid .post-nav {
  height: 56px;
}

.post-home {
  font-size: 18px;
  font-weight: 900;
  letter-spacing: 0;
}

.post-back {
  position: relative;
  padding-bottom: 5px;
  font-size: 12px;
  font-weight: 400;
}

.post-back::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  content: "";
  background: currentColor;
}

.post-cover {
  position: relative;
  display: grid;
  height: 348px;
  place-items: center;
  overflow: hidden;
  background: var(--hero);
  color: #fff;
}

.post-cover-motion {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.7;
  pointer-events: none;
}

.post-cover-content {
  position: relative;
  z-index: 2;
  width: min(1180px, calc(100% - 48px));
  margin-top: 28px;
  text-align: center;
}

.post-cover-content h1 {
  margin: 0;
  color: #fff;
  font-size: 34px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: 0;
}

.post-cover-content p {
  display: flex;
  gap: 9px;
  align-items: center;
  justify-content: center;
  margin: 16px 0 0;
  color: #fff;
  font-size: 11px;
  font-weight: 700;
}

.post-page {
  padding: 76px 0 110px;
}

.post-hero {
  width: min(820px, calc(100% - 48px));
  margin: 0 auto;
}

.post-hero img {
  display: block;
  width: 100%;
  height: 430px;
  object-fit: contain;
  object-position: center;
  background: #f4f4f4;
}

.post-article {
  width: min(820px, calc(100% - 48px));
  margin: 26px auto 0;
}

.post-article h1 {
  margin: 0;
  font-size: 34px;
  font-weight: 800;
  line-height: 1.26;
  letter-spacing: 0;
}

.post-meta {
  margin: 9px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.post-language-toggle {
  display: inline-grid;
  grid-template-columns: repeat(2, auto);
  gap: 0;
  overflow: hidden;
  margin-top: 18px;
  border: 1px solid #171717;
}

.post-language-toggle button {
  min-width: 56px;
  height: 34px;
  border: 0;
  background: #fff;
  color: #171717;
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
}

.post-language-toggle button + button {
  border-left: 1px solid #171717;
}

.post-language-toggle button.is-active {
  background: #171717;
  color: #fff;
}

.post-content {
  margin: 40px 0 0;
}

.post-content p {
  margin: 0 0 24px;
  color: #444b52;
  font-size: 18px;
  line-height: 1.9;
  text-align: justify;
}

@media (max-width: 700px) {
  .post-nav {
    width: min(100% - 34px, 842px);
    height: 74px;
  }

  .post-header.is-solid .post-nav {
    height: 54px;
  }

  .post-cover {
    height: 310px;
  }

  .post-cover-content {
    width: min(100% - 34px, 1180px);
    margin-top: 18px;
  }

  .post-cover-content h1 {
    font-size: 30px;
  }

  .post-page {
    padding-top: 48px;
  }

  .post-hero,
  .post-article {
    width: min(100% - 34px, 820px);
  }

  .post-hero img {
    height: 250px;
  }

  .post-article h1 {
    font-size: 24px;
  }

  .post-content p {
    font-size: 16px;
    line-height: 1.85;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .post-cover-motion {
    display: none;
  }
}