:root {
  --blade-jade: #0F766E;
  --blade-jade-light: #115E59;
  --blade-jade-dark: #0D4A46;
  --immortal-gold: #FCD34D;
  --immortal-gold-deep: #A16207;
  --sword-blue: #60A5FA;
  --sword-blue-deep: #1E40AF;
  --ink-black: #0a0a0a;
  --ink-black-light: #141414;
  --radius-sharp: 4px;
  --radius-soft: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Noto Sans SC", system-ui, -apple-system, sans-serif;
  background-color: var(--ink-black);
  color: #f3f4f6;
}

.header-glass {
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav-link {
  color: #d1d5db;
  font-size: clamp(0.875rem, 1vw, 1rem);
  font-weight: 500;
  position: relative;
  transition: color 0.25s ease;
  padding: 0.25rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--immortal-gold), var(--sword-blue));
  transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--immortal-gold);
}

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

.mobile-nav-link {
  display: block;
  padding: 0.75rem 0;
  color: #d1d5db;
  font-size: 1rem;
  border-bottom: 1px solid rgba(15, 118, 110, 0.2);
  transition: color 0.2s ease;
}

.mobile-nav-link:last-of-type {
  border-bottom: none;
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  color: var(--immortal-gold);
}

.btn-primary {
  background: linear-gradient(135deg, var(--blade-jade), var(--blade-jade-light));
  color: #fff;
  border-radius: var(--radius-sharp);
  font-weight: 600;
  border: 1px solid rgba(252, 211, 77, 0.3);
  box-shadow: 0 4px 15px rgba(15, 118, 110, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease, filter 0.2s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(15, 118, 110, 0.55);
  filter: brightness(1.1);
}

.btn-download {
  background: linear-gradient(135deg, var(--blade-jade), var(--sword-blue-deep));
  color: #fff;
  border-radius: 9999px;
  font-weight: 800;
  box-shadow: 0 10px 40px rgba(15, 118, 110, 0.5), 0 0 0 4px rgba(96, 165, 250, 0.15);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.btn-download:hover {
  transform: scale(1.03);
  box-shadow: 0 14px 50px rgba(15, 118, 110, 0.65), 0 0 0 6px rgba(96, 165, 250, 0.25);
}

.section-spacing {
  padding: clamp(3rem, 8vw, 6rem) 0;
}

.section-title {
  text-align: center;
}

.title-deco {
  width: 80px;
  height: 3px;
  margin: 0 auto;
  background: linear-gradient(90deg, transparent, var(--immortal-gold), var(--sword-blue), transparent);
  border-radius: 2px;
}

.contact-card {
  background: linear-gradient(180deg, rgba(20, 20, 20, 0.95), rgba(10, 10, 10, 0.98));
  border: 1px solid rgba(15, 118, 110, 0.25);
  border-radius: var(--radius-soft);
  padding: 1.5rem;
  text-align: center;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.contact-card:hover {
  transform: translateY(-4px);
  border-color: rgba(96, 165, 250, 0.45);
}

.qr-wrap {
  width: 140px;
  height: 140px;
  margin: 0 auto;
  border-radius: var(--radius-sharp);
  overflow: hidden;
  border: 2px solid rgba(252, 211, 77, 0.25);
  box-shadow: 0 0 20px rgba(15, 118, 110, 0.2);
}

/* Guide layout */
.guide-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 1024px) {
  .guide-layout {
    grid-template-columns: 280px 1fr;
  }
}

.toc-sidebar {
  align-self: start;
}

.toc-panel {
  background: linear-gradient(180deg, rgba(20, 20, 20, 0.95), rgba(10, 10, 10, 0.98));
  border: 1px solid rgba(15, 118, 110, 0.25);
  border-radius: var(--radius-soft);
  padding: 1.5rem;
  position: sticky;
  top: 90px;
}

.toc-link {
  display: flex;
  align-items: center;
  color: #d1d5db;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sharp);
  font-size: clamp(0.875rem, 1vw, 0.95rem);
  transition: background 0.2s ease, color 0.2s ease;
}

.toc-link:hover,
.toc-link.active {
  background: rgba(15, 118, 110, 0.18);
  color: var(--immortal-gold);
}

/* Article content */
.article-content {
  background: linear-gradient(180deg, rgba(20, 20, 20, 0.95), rgba(10, 10, 10, 0.98));
  border: 1px solid rgba(15, 118, 110, 0.25);
  border-radius: var(--radius-soft);
  padding: clamp(1.5rem, 4vw, 2.5rem);
}

.article-section {
  padding-bottom: 2rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid rgba(15, 118, 110, 0.18);
}

.article-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.article-section h2 {
  font-family: "Ma Shan Zheng", cursive;
  font-size: clamp(1.5rem, 3vw, 1.875rem);
  color: var(--immortal-gold);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--blade-jade), var(--sword-blue-deep));
  border-radius: var(--radius-sharp);
  color: #fff;
  font-size: 1rem;
}

.article-section p {
  color: #d1d5db;
  line-height: 1.85;
  margin-bottom: 1rem;
  font-size: clamp(0.9375rem, 1.5vw, 1rem);
}

.article-section ul {
  list-style: none;
  padding-left: 0;
  margin-bottom: 1rem;
}

.article-section li {
  color: #d1d5db;
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.75rem;
  line-height: 1.7;
}

.article-section li::before {
  content: '◆';
  position: absolute;
  left: 0;
  color: var(--sword-blue);
  font-size: 0.75rem;
  top: 0.15rem;
}

.article-section strong {
  color: var(--immortal-gold);
  font-weight: 600;
}

.code-list-inline {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1rem 0;
}

.code-chip {
  background: rgba(252, 211, 77, 0.1);
  border: 1px solid rgba(252, 211, 77, 0.35);
  color: var(--immortal-gold);
  padding: 0.35rem 0.9rem;
  border-radius: var(--radius-sharp);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-weight: 700;
  font-size: 0.95rem;
}

/* Position-specific image sizing */

header img { height: 2.5rem; width: auto; }
.hero img { max-height: 40vh; width: auto; }
.feature-img img { width: 100%; height: 220px; object-fit: cover; }
.qr-card img { width: 100%; max-width: 160px; height: auto; }
footer img { width: 100%; max-width: 120px; height: auto; }

/* Friendly links block */

.friendly-links.yjbh { padding: 3rem 1rem; background: #0a0a0a; border-top: 1px solid rgba(21,128,61,.35); }
.friendly-links.yjbh .friendly-links-inner { max-width: 1200px; margin: 0 auto; text-align: center; }
.friendly-links.yjbh h2 { font-family: 'Ma Shan Zheng', cursive; font-size: clamp(1.6rem, 4vw, 2.4rem); color: #FCD34D; margin-bottom: .25rem; }
.friendly-links.yjbh h2 i { color: #15803D; margin-right: .5rem; }
.friendly-links.yjbh p { color: #9CA3AF; margin-bottom: 1.5rem; }
.friendly-links.yjbh ul { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: .75rem; list-style: none; padding: 0; margin: 0; }
.friendly-links.yjbh li a { display: block; padding: .6rem .8rem; border-radius: .5rem; background: rgba(21,128,61,.12); border: 1px solid rgba(21,128,61,.35); color: #E5E7EB; font-size: .9rem; transition: .2s; }
.friendly-links.yjbh li a:hover { background: rgba(252,211,77,.12); border-color: #FCD34D; color: #FCD34D; transform: translateY(-2px); }
@media (max-width: 375px) { .friendly-links.yjbh ul { grid-template-columns: repeat(2, 1fr); } }