:root {
  --primary-background: #F7F7F7;
  --content-background: #FFFFFF;
  --primary-text: #1A1A1A;
  --secondary-text: #4A4A4A;
  --border-color: #E5E5E5;
  --brand: #00A86B;
  --brand-dark: #007A4D;
  --accent: #FF6B35;
  --glass-white: rgba(255,255,255,0.78);
  --hero-overlay: rgba(0,168,107,0.08);
  --font-heading: "SF Pro Display", "Source Han Sans CN", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Source Han Serif CN", "Songti SC", "Noto Serif CJK SC", serif;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.05);
  --shadow-md: 0 16px 40px rgba(0,0,0,0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--primary-background);
  color: var(--primary-text);
  line-height: 1.75;
}

main {
  display: block;
  min-height: 60vh;
}

#main-content {
  scroll-margin-top: 6rem;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  font-weight: 400;
  color: var(--primary-text);
  letter-spacing: 0.05em;
  line-height: 1.2;
}

p {
  margin: 0 0 1.2rem;
}

a {
  color: var(--brand-dark);
}

a:hover {
  color: var(--brand);
}

ul,
ol {
  margin: 0;
  padding: 0;
}

li {
  list-style: none;
}

button {
  font: inherit;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 300;
  transform: translateY(-150%);
  background: var(--brand);
  color: #FFFFFF;
  padding: 0.8rem 1.2rem;
  font-family: var(--font-heading);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-decoration: none;
  transition: transform 0.2s ease;
}

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

.site-header {
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  border-bottom: 1px solid var(--border-color);
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 6px;
  background: linear-gradient(180deg, var(--brand), var(--brand-dark));
}

.site-header-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(1rem, 3vw, 3rem);
  max-width: 1440px;
  margin: 0 auto;
  padding: 0.65rem clamp(1rem, 3vw, 2.5rem) 0.65rem calc(clamp(1rem, 3vw, 2.5rem) + 6px);
  min-height: 68px;
}

.brand-mark {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  text-decoration: none;
  color: var(--primary-text);
}

.brand-cube {
  flex: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3px;
  width: 38px;
  height: 38px;
  transform: rotate(-6deg);
}

.brand-cube-face {
  background: var(--brand);
  border-radius: 1px;
}

.brand-cube-face:nth-child(2) {
  background: var(--accent);
}

.brand-cube-face:nth-child(3) {
  background: var(--brand-dark);
}

.brand-cube-face:nth-child(4) {
  background: rgba(0,168,107,0.12);
  border: 1px solid var(--brand);
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-title {
  font-family: var(--font-heading);
  font-size: 1.08rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  line-height: 1.2;
  white-space: nowrap;
}

.brand-tagline {
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  color: var(--secondary-text);
  line-height: 1.4;
  margin-top: 0.15rem;
}

.site-header-navgroup {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.nav-link {
  position: relative;
  display: block;
  padding: 0.75rem 0.8rem;
  font-family: var(--font-heading);
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  text-decoration: none;
  color: var(--primary-text);
  white-space: nowrap;
  transition: background 0.2s, color 0.2s, transform 0.2s, box-shadow 0.2s;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0.8rem;
  right: 0.8rem;
  bottom: 0.35rem;
  height: 2px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.nav-link:hover {
  color: var(--brand-dark);
  transform: translateY(-1px);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--brand-dark);
  font-weight: 500;
}

.header-icp {
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  color: var(--secondary-text);
  border-left: 1px solid var(--border-color);
  padding-left: 1rem;
  margin-left: 0.2rem;
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  background: rgba(0,168,107,0.08);
  border: 1px solid rgba(0,168,107,0.25);
  border-radius: 2px;
  padding: 0.45rem 0.6rem;
  color: var(--brand-dark);
}

.nav-toggle-box {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 22px;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle-label {
  font-size: 0.6rem;
  letter-spacing: 0.1em;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

body.nav-is-open {
  overflow: hidden;
}

@media (max-width: 960px) {
  .site-header-inner {
    min-height: 64px;
  }

  .brand-tagline {
    display: none;
  }

  .header-icp {
    display: none;
  }

  .site-header-navgroup {
    display: contents;
  }

  .nav-toggle {
    display: flex;
    z-index: 120;
  }

  .site-nav {
    position: fixed;
    inset: 0;
    z-index: 110;
    align-items: stretch;
    justify-content: flex-start;
    flex-direction: column;
    padding: calc(64px + 1rem) 1.5rem 2rem;
    background: rgba(255,255,255,0.94);
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-2%);
    transition: transform 0.4s ease, opacity 0.4s ease, visibility 0.4s ease;
  }

  .site-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0.1rem;
  }

  .nav-link {
    padding: 1rem 0.2rem;
    font-size: 1.15rem;
    border-bottom: 1px solid var(--border-color);
  }

  .nav-link::after {
    left: 0;
    right: 0;
    bottom: 0;
  }
}

.site-footer {
  background: #0E231B;
  color: rgba(255,255,255,0.78);
  border-top: 6px solid var(--brand);
}

.site-footer a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--accent);
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.7fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4rem);
  max-width: 1440px;
  margin: 0 auto;
  padding: clamp(2.5rem, 6vw, 5rem) clamp(1rem, 3vw, 2.5rem);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.9rem;
}

.footer-logo {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: #FFFFFF;
}

.footer-tagline {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  opacity: 0.75;
}

.footer-trust {
  font-size: 0.82rem;
  line-height: 1.9;
  color: rgba(255,255,255,0.6);
  max-width: 58ch;
}

.footer-col {
  min-width: 0;
}

.footer-h {
  margin: 0 0 1rem;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #FFFFFF;
}

.footer-links {
  display: grid;
  gap: 0.7rem;
}

.footer-links a {
  font-family: var(--font-heading);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
}

.footer-contact-list {
  display: grid;
  gap: 0.7rem;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.72);
}

.footer-contact-item {
  display: block;
}

.footer-support {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.5);
  margin-top: 1rem;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.2rem clamp(1rem, 3vw, 2.5rem);
  border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
}

.footer-legal a {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.footer-copy,
.footer-icp {
  margin: 0;
  font-size: 0.72rem;
  color: rgba(255,255,255,0.55);
}

@media (max-width: 820px) {
  .footer-main {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

.container {
  width: min(100% - 2rem, 1280px);
  margin-inline: auto;
}

.section {
  padding-block: clamp(3.5rem, 8vw, 7rem);
}

.section-header {
  max-width: 56rem;
  margin-bottom: clamp(2rem, 5vw, 4rem);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-heading);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brand-dark);
  margin-bottom: 0.8rem;
}

.eyebrow::before {
  content: "";
  width: 2.4rem;
  height: 2px;
  background: var(--brand);
}

.title-xl {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  font-weight: 300;
  letter-spacing: 0.04em;
  line-height: 1.05;
}

.title-lg {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 300;
}

.title-md {
  margin: 0;
  font-size: clamp(1.15rem, 2vw, 1.55rem);
  font-weight: 400;
}

.lead {
  font-size: 1rem;
  line-height: 1.95;
  color: var(--secondary-text);
  max-width: 68ch;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  padding-block: 1.2rem;
  color: var(--secondary-text);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.breadcrumb-item::after {
  content: "/";
  margin-left: 0.5rem;
  color: var(--border-color);
}

.breadcrumb-item:last-child::after {
  display: none;
}

.breadcrumb-link {
  text-decoration: none;
  color: var(--brand-dark);
}

.breadcrumb-current {
  color: var(--secondary-text);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.25rem;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-heading);
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.btn-primary {
  background: var(--brand);
  color: #FFFFFF;
}

.btn-accent {
  background: var(--accent);
  color: #FFFFFF;
}

.btn-ghost {
  background: transparent;
  color: var(--primary-text);
  border-color: var(--border-color);
}

.btn-primary:hover,
.btn-accent:hover,
.btn-ghost:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 2rem);
}

.col-span-4 {
  grid-column: span 4;
}

.col-span-5 {
  grid-column: span 5;
}

.col-span-6 {
  grid-column: span 6;
}

.col-span-7 {
  grid-column: span 7;
}

.col-span-8 {
  grid-column: span 8;
}

.col-span-12 {
  grid-column: span 12;
}

@media (max-width: 900px) {
  .col-span-4,
  .col-span-5,
  .col-span-6,
  .col-span-7,
  .col-span-8 {
    grid-column: span 12;
  }
}

.split-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(1.5rem, 4vw, 4rem);
  align-items: start;
}

.split-aside {
  position: sticky;
  top: 6rem;
}

.split-index {
  min-width: 0;
}

@media (max-width: 960px) {
  .split-layout {
    grid-template-columns: 1fr;
  }

  .split-aside {
    position: static;
  }
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: clamp(2rem, 6vw, 5rem);
  min-height: 70vh;
  padding-block: clamp(4rem, 10vw, 8rem);
  overflow: hidden;
  align-items: center;
}

.hero::before {
  content: "";
  position: absolute;
  right: -6%;
  top: -6%;
  width: 36%;
  aspect-ratio: 1 / 1;
  background: var(--hero-overlay);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}

.hero::after {
  content: "";
  position: absolute;
  right: 4%;
  bottom: -12%;
  width: 26%;
  aspect-ratio: 1 / 1;
  background: rgba(255,107,53,0.14);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
}

.hero-copy,
.hero-media {
  position: relative;
  z-index: 1;
}

.hero-copy {
  max-width: 42rem;
}

.hero-media {
  border-top: 4px solid var(--brand);
  border-bottom: 1px solid var(--border-color);
  padding: clamp(1.25rem, 3vw, 2.5rem);
  background: linear-gradient(135deg, rgba(0,168,107,0.10), rgba(255,255,255,0.8));
  box-shadow: var(--shadow-md);
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }
}

.chapter {
  display: grid;
  grid-template-columns: minmax(0, 0.32fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 4rem);
  padding-block: clamp(2.5rem, 6vw, 4rem);
  border-top: 1px solid var(--border-color);
  align-items: start;
}

.chapter-index {
  font-family: var(--font-heading);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--brand-dark);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.chapter-index::before {
  content: "";
  width: 1.8rem;
  height: 2px;
  background: var(--accent);
}

.chapter-body {
  min-width: 0;
}

@media (max-width: 720px) {
  .chapter {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}

.panel {
  background: var(--content-background);
  border: 1px solid var(--border-color);
  padding: clamp(1.25rem, 3vw, 2.5rem);
  box-shadow: var(--shadow-sm);
}

.glass-panel {
  background: var(--glass-white);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid rgba(255,255,255,0.6);
  box-shadow: var(--shadow-md);
}

.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, rgba(0,168,107,0.12), rgba(255,255,255,0.7) 45%, rgba(255,107,53,0.12));
  border: 1px solid var(--border-color);
}

.media-frame::before {
  content: "";
  position: absolute;
  width: 42%;
  height: 42%;
  right: -6%;
  top: -6%;
  background: repeating-linear-gradient(45deg, var(--brand), var(--brand) 2px, transparent 2px, transparent 12px);
  opacity: 0.22;
}

.media-frame::after {
  content: "";
  position: absolute;
  left: 10%;
  bottom: 8%;
  width: 55%;
  height: 18px;
  background: linear-gradient(90deg, rgba(0,168,107,0.55), rgba(255,107,53,0.35));
  filter: blur(14px);
  opacity: 0.8;
}

.media-frame[data-variant="portrait"] {
  aspect-ratio: 3 / 4;
}

.media-frame[data-variant="wide"] {
  aspect-ratio: 16 / 9;
}

.media-frame[data-variant="leaf"] {
  aspect-ratio: 1 / 1;
  border-radius: 2px 40% 2px 2px;
}

.media-frame[data-variant="leaf"]::before {
  border-radius: 0 0 0 40%;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.3rem 0.65rem;
  font-family: var(--font-heading);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--brand-dark);
  background: rgba(0,168,107,0.08);
  border: 1px solid rgba(0,168,107,0.22);
  border-radius: 1px;
}

.tag-accent {
  color: #FFFFFF;
  background: var(--accent);
  border-color: var(--accent);
}

.tag-new {
  color: #FFFFFF;
  background: var(--brand);
  border-color: var(--brand);
}

.index-list {
  display: grid;
  border-top: 1px solid var(--border-color);
}

.index-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0.25rem;
  border-bottom: 1px solid var(--border-color);
  text-decoration: none;
  color: var(--primary-text);
  font-family: var(--font-heading);
  font-size: 0.88rem;
  letter-spacing: 0.08em;
}

.index-link::after {
  content: "→";
  color: var(--brand);
  font-size: 1.2rem;
  transition: transform 0.3s;
}

.index-link:hover {
  color: var(--brand-dark);
}

.index-link:hover::after {
  transform: translateX(5px);
}

.status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand);
  box-shadow: 0 0 0 3px rgba(0,168,107,0.15);
}

.status-dot.is-warning {
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(255,107,53,0.18);
}

.status-dot.is-neutral {
  background: var(--secondary-text);
  box-shadow: 0 0 0 3px rgba(74,74,74,0.12);
}

.divider {
  height: 1px;
  background: var(--border-color);
  border: 0;
  margin: 2rem 0;
}

.qa-list {
  border-top: 1px solid var(--border-color);
}

.qa-item {
  border-bottom: 1px solid var(--border-color);
}

.qa-trigger {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  width: 100%;
  padding: 1.25rem 0.2rem;
  background: none;
  border: 0;
  text-align: left;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  color: var(--primary-text);
}

.qa-trigger::after {
  content: "＋";
  flex: none;
  color: var(--brand);
  font-size: 1.3rem;
  line-height: 1;
  transition: transform 0.3s, color 0.3s;
}

.qa-item[data-open] .qa-trigger::after {
  content: "－";
  color: var(--accent);
}

.qa-panel {
  display: grid;
  grid-template-rows: 0fr;
  visibility: hidden;
  opacity: 0;
  transition: grid-template-rows 0.4s ease, opacity 0.3s ease, visibility 0.3s ease;
}

.qa-item[data-open] .qa-panel {
  grid-template-rows: 1fr;
  visibility: visible;
  opacity: 1;
}

.qa-panel-inner {
  overflow: hidden;
  min-height: 0;
}

.qa-panel-inner p {
  padding-bottom: 1.25rem;
  margin: 0;
  color: var(--secondary-text);
}

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