:root {
  /* Botanical Research Notebook / Latent Garden */
  --bg: #f9f7f1;
  --panel: rgba(252, 250, 245, 0.9);
  --panel-strong: rgba(252, 250, 245, 0.96);
  --panel-soft: #f2efe6;

  --text: #3a3832;
  --text-soft: #4a473f;
  --muted: #7a7870;

  --accent: #5c7560;
  --accent-hover: #4a5e4b;
  --accent-light: #e8ece6;
  --accent-line: rgba(92, 117, 96, 0.18);

  --warm: #8b7355;
  --warm-soft: #f0e8dc;

  --border: rgba(58, 56, 50, 0.08);
  --border-soft: rgba(58, 56, 50, 0.05);

  --shadow: 0 6px 18px rgba(58, 56, 50, 0.05);
  --shadow-soft: 0 3px 10px rgba(58, 56, 50, 0.035);

  --hero-bg: rgba(252, 250, 245, 0.92);
  --list-accent: rgba(238, 242, 238, 0.92);

  --paper-dot: rgba(58, 56, 50, 0.012);
  --paper-line: rgba(58, 56, 50, 0.018);

  --header-bg: rgba(246, 243, 238, 0.82);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.8;
  font-size: 16px;
  letter-spacing: 0.01em;
  background-color: var(--bg);
  background-image:
    url("../background.png"),
    radial-gradient(circle at 20% 20%, rgba(139, 115, 85, 0.025) 0%, transparent 32%),
    radial-gradient(circle at 80% 30%, rgba(92, 117, 96, 0.02) 0%, transparent 30%),
    repeating-radial-gradient(
      circle at 50% 50%,
      transparent 0,
      transparent 2px,
      var(--paper-dot) 2px,
      var(--paper-dot) 4px
    );
  background-size: cover, auto, auto, 4px 4px;
  background-position: center top, center, center, center;
  background-repeat: no-repeat, no-repeat, no-repeat, repeat;
  background-attachment: fixed, scroll, scroll, local;
}

/* 移动端优化：使用移动端专属背景图 */
@media (max-width: 720px) {
  body {
    background-image: url("../background-mobile.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: scroll;
  }
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease, opacity 0.2s ease;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

.wrap {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  backdrop-filter: blur(10px);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border-soft);
  z-index: 50;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 16px 0;
  align-items: center;
  position: relative;
}

.site-brand {
  min-width: 0;
}

.site-title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.site-title a {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.site-title a:hover {
  color: var(--accent);
  text-decoration: none;
}

.site-logo {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--border);
  box-shadow: 0 2px 10px rgba(58, 56, 50, 0.04);
  flex-shrink: 0;
}

.site-tagline {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.site-nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  align-items: center;
}

.site-nav a {
  color: var(--text);
  font-weight: 500;
  padding: 4px 2px;
  position: relative;
}

.site-nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.22s ease;
}

.site-nav a:hover::after,
.site-nav a.active::after {
  width: 100%;
}

/* Mobile menu */

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
  z-index: 100;
  margin-left: auto;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: all 0.3s ease;
  border-radius: 2px;
}

.menu-toggle:hover span {
  background: var(--accent);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

.mobile-nav {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: rgba(251, 249, 246, 0.98);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px 16px;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.04);
}

.mobile-nav a {
  display: block;
  padding: 12px 0;
  color: var(--text);
  font-weight: 500;
  font-size: 1rem;
  border-bottom: 1px solid rgba(47, 49, 45, 0.06);
}

.mobile-nav a:last-child {
  border-bottom: none;
}

.mobile-nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

/* Layout */

main.wrap {
  padding: 32px 0 48px;
}

/* Generic card */

.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  box-shadow: var(--shadow-soft);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease, background 0.2s ease;
  backdrop-filter: blur(1.5px);
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-radial-gradient(
      circle at 30% 20%,
      transparent 0,
      transparent 2px,
      rgba(58, 56, 50, 0.008) 2px,
      rgba(58, 56, 50, 0.008) 4px
    );
  opacity: 0.55;
  pointer-events: none;
}

.card > * {
  position: relative;
  z-index: 1;
}

.card:hover {
  border-color: rgba(92, 117, 96, 0.15);
  box-shadow: 0 10px 24px rgba(58, 56, 50, 0.07);
}

/* Hero */

.hero {
  position: relative;
  padding: 32px 28px;
  margin-bottom: 28px;
  background: var(--hero-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.18), rgba(255,255,255,0)),
    radial-gradient(circle at 85% 20%, rgba(92,117,96,0.035), transparent 28%);
  pointer-events: none;
}

.hero h1 {
  position: relative;
  z-index: 1;
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-size: 2rem;
  font-weight: 600;
  margin: 0 0 10px;
  color: var(--text);
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.hero p,
.hero ul,
.hero li {
  position: relative;
  z-index: 1;
}

.hero p {
  margin: 0 0 12px;
  color: var(--text-soft);
  font-size: 1rem;
  line-height: 1.7;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--warm);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
}

/* Grid sections */

.grid {
  display: grid;
  gap: 16px;
  margin-bottom: 24px;
}

.three-up {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.section-card {
  background: rgba(252, 250, 245, 0.88);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.section-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 26px rgba(47, 49, 45, 0.06);
  border-color: rgba(66, 107, 87, 0.14);
  background: rgba(252, 250, 245, 0.94);
}

.section-card h2,
.post-item h2,
.post-item h3 {
  margin-top: 0;
  color: var(--text);
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.section-card h2 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.post-item h2 {
  font-size: 1.15rem;
}

.post-item h3 {
  font-size: 1.1rem;
}

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.section-head h2 {
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0;
  color: var(--text);
  letter-spacing: -0.01em;
}

/* Post list */

.post-list {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

.post-item {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 20px 20px 22px;
  transition: all 0.2s ease;
  overflow: hidden;
}

.post-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  bottom: 14px;
  width: 3px;
  background: linear-gradient(
    180deg,
    rgba(92, 117, 96, 0),
    rgba(92, 117, 96, 0.22),
    rgba(92, 117, 96, 0)
  );
  border-radius: 2px;
}

.post-item:hover {
  border-color: rgba(92, 117, 96, 0.2);
  box-shadow: var(--shadow-soft);
}

.post-item:first-child {
  background: var(--list-accent);
}

.meta {
  color: var(--muted);
  font-size: 0.9rem;
}

/* Article */

.article {
  background: rgba(252, 250, 245, 0.9);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 30px;
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(1px);
}

.article h1 {
  margin-bottom: 12px;
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-size: 2rem;
  letter-spacing: -0.02em;
  font-weight: 600;
  color: var(--text);
  line-height: 1.15;
}

.article h2,
.article h3,
.article h4,
.article h5,
.article h6 {
  position: relative;
  font-family: "Cormorant Garamond", "Noto Serif SC", "Source Han Serif CN", serif;
  font-weight: 600;
  margin-top: 1.8em;
  color: var(--text);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.article h2 {
  font-size: 1.5rem;
  padding-bottom: 0.28em;
  border-bottom: 1px solid rgba(92, 117, 96, 0.14);
}

.article h3 {
  font-size: 1.3rem;
}

.prose :first-child {
  margin-top: 0;
}

.prose p,
.prose li {
  color: var(--text-soft);
}

.prose img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

.prose blockquote {
  margin: 1.2rem 0;
  padding: 1rem 1.2rem;
  background: rgba(242, 239, 230, 0.88);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  color: var(--text);
  font-style: normal;
}

.prose code {
  background: rgba(242, 239, 230, 0.92);
  padding: 0.18rem 0.42rem;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--accent-hover);
}

.prose pre {
  background: rgba(242, 239, 230, 0.96);
  padding: 16px;
  border-radius: 10px;
  overflow-x: auto;
  border: 1px solid var(--border);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.35);
}

.prose pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

/* Tags */

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.tag {
  display: inline-flex;
  padding: 4px 10px;
  border-radius: 4px;
  background: var(--panel-soft);
  color: var(--accent);
  font-size: 0.8rem;
  border: 1px solid var(--border);
  font-weight: 500;
  font-family: "PingFang SC", sans-serif;
}

.tag:first-child {
  background: var(--accent-light);
  border-color: rgba(92, 117, 96, 0.12);
  color: var(--accent);
}

/* Footer */

.site-footer {
  padding: 0 0 48px;
  color: var(--muted);
  font-size: 0.9rem;
}

/* Mobile */

@media (max-width: 720px) {
  body {
    background-image:
      radial-gradient(circle at 0% 0%, rgba(139, 115, 85, 0.03) 0%, transparent 40%),
      radial-gradient(circle at 100% 0%, rgba(139, 115, 85, 0.03) 0%, transparent 40%),
      radial-gradient(circle at 0% 100%, rgba(139, 115, 85, 0.03) 0%, transparent 40%),
      radial-gradient(circle at 100% 100%, rgba(139, 115, 85, 0.03) 0%, transparent 40%),
      url("../background-mobile.png"),
      repeating-radial-gradient(
        circle at 50% 50%,
        transparent 0,
        transparent 2px,
        rgba(58, 56, 50, 0.01) 2px,
        rgba(58, 56, 50, 0.01) 4px
      );
    background-size: auto, auto, auto, auto, cover, 4px 4px;
    background-position: center, center, center, center, center top, center;
    background-repeat: no-repeat, no-repeat, no-repeat, no-repeat, no-repeat, repeat;
    background-attachment: scroll, scroll, scroll, scroll, scroll, local;
  }

  .header-inner,
  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .menu-toggle {
    display: flex;
    position: absolute;
    right: 0;
    top: 18px;
  }

  .site-nav {
    display: none;
  }

  .site-nav.active,
  .mobile-nav.active {
    display: block;
  }

  .card,
  .hero,
  .article {
    padding: 20px;
  }

  .article h1 {
    font-size: 1.5rem;
  }

  .hero h1 {
    font-size: 1.7rem;
  }

  .site-title {
    font-size: 1.4rem;
    padding-right: 56px;
  }

  .site-logo {
    width: 40px;
    height: 40px;
  }

  .site-tagline {
    font-size: 0.88rem;
  }

  .three-up {
    grid-template-columns: 1fr;
  }

  .post-item {
    padding: 18px 16px 18px 18px;
  }
}