@font-face {
  font-family: "SosoTalk Handwriting";
  src: url("/assets/ZhiMangXing-Regular.ttf") format("truetype");
  font-display: swap;
}

:root {
  --paper: rgb(236 231 219);
  --ink: rgb(48 33 23 / 92%);
  --panel: rgb(246 242 231);
  --vermilion: rgb(157 77 57);
  --ink-soft: rgb(48 33 23 / 70%);
  --line: rgb(48 33 23 / 17%);
  --paper-shadow: rgb(48 33 23 / 13%);
  --reading-width: 70rem;
  --body-font: -apple-system, blinkmacsystemfont, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body-font);
  line-height: 1.7;
}

body {
  min-width: 20rem;
  margin: 0;
  background:
    radial-gradient(circle at 12% 16%, rgb(255 255 255 / 46%), transparent 22rem),
    radial-gradient(circle at 83% 6%, rgb(48 33 23 / 6%), transparent 27rem),
    repeating-linear-gradient(102deg, rgb(112 94 68 / 3%) 0 1px, transparent 1px 10px),
    var(--paper);
}

a {
  color: inherit;
  text-underline-offset: 0.18em;
}

.link-card a {
  color: var(--vermilion);
  font-weight: 700;
}

:where(a):hover {
  color: var(--vermilion);
}

a:focus-visible {
  outline: 3px solid var(--vermilion);
  outline-offset: 4px;
}

img {
  display: block;
  max-width: 100%;
}

.skip-link {
  position: absolute;
  z-index: 2;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.45rem 0.8rem;
  background: var(--panel);
  border: 1px solid var(--line);
  transform: translateY(-180%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header,
.site-footer {
  width: min(calc(100% - 2rem), var(--reading-width));
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--line);
}

.brand-name {
  margin: 0;
  font-family: "SosoTalk Handwriting", var(--body-font);
  font-size: clamp(1.65rem, 4vw, 2.35rem);
  line-height: 1.15;
}

.brand-name a,
.site-header nav a {
  text-decoration: none;
}

.site-header nav,
.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
}

.site-header nav {
  justify-content: flex-end;
  font-size: 0.94rem;
}

.paper-sheet {
  width: min(calc(100% - 2rem), var(--reading-width));
  min-height: 30rem;
  margin: 1.4rem auto 2rem;
  padding: clamp(1.5rem, 5vw, 4.5rem);
  background:
    radial-gradient(ellipse at center, transparent 58%, rgb(48 33 23 / 8%) 125%),
    repeating-linear-gradient(0deg, rgb(126 105 75 / 3%) 0 1px, transparent 1px 8px),
    var(--panel);
  border: 1px solid rgb(48 33 23 / 12%);
  box-shadow: 0 1.1rem 2.8rem var(--paper-shadow);
}

.paper-sheet section + section {
  margin-top: clamp(3.5rem, 10vw, 6.5rem);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 1.5rem;
}

.hero-title {
  max-width: 12ch;
  margin: 0;
  font-family: "SosoTalk Handwriting", var(--body-font);
  font-size: clamp(2.8rem, 8vw, 5.7rem);
  font-weight: 400;
  line-height: 1.08;
}

.hero-copy,
.section-intro {
  max-width: 42rem;
  color: var(--ink-soft);
  font-size: 1.08rem;
}

.app-icon {
  width: clamp(5.5rem, 16vw, 9rem);
  height: auto;
  border-radius: 23%;
  box-shadow: 0 0.8rem 1.6rem rgb(48 33 23 / 17%);
}

.section-heading {
  margin: 0;
  font-size: clamp(1.5rem, 4vw, 2.15rem);
  line-height: 1.3;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.feature-card,
.link-card,
.ink-note {
  background: rgb(255 255 255 / 22%);
  border: 1px solid var(--line);
  border-radius: 0.35rem;
}

.feature-card,
.link-card {
  padding: 1.25rem;
}

.feature-card h3,
.link-card h3 {
  margin-top: 0;
  font-size: 1.14rem;
}

.feature-card p,
.link-card p {
  margin-bottom: 0;
  color: var(--ink-soft);
}

.ink-note {
  max-width: 47rem;
  padding: 1.2rem 1.35rem;
  border-left: 0.28rem solid var(--vermilion);
  color: var(--ink-soft);
}

.ink-note .decorative-mark {
  display: block;
  margin-bottom: 0.15rem;
  color: var(--vermilion);
  font-family: "SosoTalk Handwriting", var(--body-font);
  font-size: 1.5rem;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.button {
  display: inline-block;
  margin-top: 0.5rem;
  padding: 0.65rem 1rem;
  background: var(--vermilion);
  color: var(--panel);
  border: 1px solid var(--vermilion);
  border-radius: 0.25rem;
  font-weight: 700;
  text-decoration: none;
}

.button:hover {
  background: transparent;
  color: var(--vermilion);
}

.legal-page {
  max-width: 48rem;
  font-family: -apple-system, blinkmacsystemfont, "PingFang SC", "Microsoft YaHei", sans-serif;
}

.site-footer {
  padding: 1.6rem 0 2.5rem;
  color: var(--ink-soft);
  font-size: 0.94rem;
}

.site-footer p {
  margin: 0.45rem 0;
}

.ink-note p:last-child {
  margin-bottom: 0;
}

.filing-status {
  color: var(--vermilion);
}

@media (width <= 48rem) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header nav {
    justify-content: flex-start;
  }

  .hero {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .link-grid {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto;
    transition-duration: 0.01ms;
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
  }
}

@media print {
  html,
  body {
    background: #fff;
  }

  .site-header,
  .site-footer {
    display: none;
  }

  .paper-sheet {
    width: 100%;
    margin: 0;
    padding: 0;
    background: transparent;
    border: 0;
    box-shadow: none;
  }

  .button {
    color: var(--ink);
    background: transparent;
  }
}