/* 
  Specimen Sheet Theme - Technical Specimen Design System
  Colors: Mineral White #F8F9F6, Volcanic Gray #323B3A, Muted Sea-Glass #91B7B2, Pale Limestone #E8E7DF
*/

:root {
  --bg-mineral: #F8F9F6;
  --text-volcanic: #323B3A;
  --accent-seaglass: #91B7B2;
  --accent-seaglass-dark: #648A85;
  --bg-limestone: #E8E7DF;
  --border-hairline: 1px solid rgba(50, 59, 58, 0.2);
  --border-hairline-strong: 1px solid rgba(50, 59, 58, 0.45);
  
  --font-heading: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", "STSong", serif;
  --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;

  --h1-desktop: 60px;
  --h1-mobile: 37px;
  --body-size: 16px;

  --container-max: 1240px;
  --header-height: 72px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--body-size);
  scroll-behavior: smooth;
  background-color: var(--bg-mineral);
  color: var(--text-volcanic);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.7;
  background-color: var(--bg-mineral);
  color: var(--text-volcanic);
  overflow-x: hidden;
}

/* Specimen Typography & Headings */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--text-volcanic);
  line-height: 1.25;
}

h1 {
  font-size: var(--h1-mobile);
  letter-spacing: -0.02em;
}

@media (min-width: 768px) {
  h1 {
    font-size: var(--h1-desktop);
  }
}

h2 {
  font-size: 1.85rem;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

@media (min-width: 768px) {
  h2 {
    font-size: 2.35rem;
  }
}

h3 {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

p {
  margin-bottom: 1.25rem;
  color: #404847;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--text-volcanic);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--accent-seaglass-dark);
}

.specimen-code, code, pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

/* Specimen Tag/Badge */
.specimen-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.65rem;
  border: var(--border-hairline);
  background-color: var(--bg-limestone);
  color: var(--text-volcanic);
  margin-bottom: 1.25rem;
}

.specimen-tag::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--accent-seaglass);
  border-radius: 50%;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}

@media (min-width: 768px) {
  .container {
    padding: 0 2rem;
  }
}

/* Specimen Section Header */
.section-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1rem;
  border-bottom: var(--border-hairline);
  position: relative;
}

.section-header .section-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-seaglass-dark);
  display: block;
  margin-bottom: 0.35rem;
  letter-spacing: 0.05em;
}

/* Header Component */
.site-header {
  height: var(--header-height);
  background-color: rgba(248, 249, 246, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: var(--border-hairline);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-header .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text-volcanic);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-code {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  background-color: var(--bg-limestone);
  padding: 0.15rem 0.4rem;
  border: var(--border-hairline);
  font-weight: 400;
}

.nav-desktop {
  display: none;
}

@media (min-width: 900px) {
  .nav-desktop {
    display: flex;
    align-items: center;
    gap: 1.75rem;
  }
  .nav-desktop a {
    font-size: 0.95rem;
    text-decoration: none;
    font-weight: 500;
    color: var(--text-volcanic);
    position: relative;
    padding: 0.25rem 0;
  }
  .nav-desktop a:hover {
    color: var(--accent-seaglass-dark);
  }
  .nav-desktop a::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 1px;
    background-color: var(--accent-seaglass);
    transition: width 0.25s ease;
  }
  .nav-desktop a:hover::after {
    width: 100%;
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--text-volcanic);
  background-color: var(--text-volcanic);
  color: var(--bg-mineral);
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn:hover {
  background-color: var(--accent-seaglass-dark);
  border-color: var(--accent-seaglass-dark);
  color: #FFFFFF;
}

.btn-secondary {
  background-color: transparent;
  color: var(--text-volcanic);
  border: var(--border-hairline-strong);
}

.btn-secondary:hover {
  background-color: var(--bg-limestone);
  color: var(--text-volcanic);
  border-color: var(--text-volcanic);
}

/* Mobile Menu Toggle */
.mobile-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: var(--border-hairline);
  cursor: pointer;
  padding: 0;
}

@media (min-width: 900px) {
  .mobile-toggle {
    display: none;
  }
}

.mobile-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--text-volcanic);
  margin: 2px 0;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.mobile-menu {
  display: none;
  position: absolute;
  top: var(--header-height);
  left: 0;
  width: 100%;
  background-color: var(--bg-mineral);
  border-bottom: var(--border-hairline-strong);
  padding: 1.5rem 1.25rem;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
}

.mobile-menu.is-active {
  display: block;
}

.mobile-menu nav {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.mobile-menu nav a {
  font-size: 1.05rem;
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 0;
  border-bottom: var(--border-hairline);
}

/* Hero Section */
.hero-section {
  padding: 3.5rem 0 4.5rem;
  border-bottom: var(--border-hairline);
  background: linear-gradient(180deg, var(--bg-mineral) 0%, var(--bg-limestone) 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 3.5rem;
  }
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-title {
  margin-bottom: 1.25rem;
}

.hero-intro {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #3A4342;
  margin-bottom: 2rem;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
}

.hero-specimen-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #606867;
  border-left: 2px solid var(--accent-seaglass);
  padding-left: 0.75rem;
}

/* Hero Network Specimen Dashboard */
.specimen-card {
  border: var(--border-hairline-strong);
  background-color: #FFFFFF;
  padding: 1.25rem;
  position: relative;
  box-shadow: 4px 4px 0px rgba(50, 59, 58, 0.06);
}

.specimen-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: var(--border-hairline);
  padding-bottom: 0.75rem;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.specimen-card-title {
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-volcanic);
}

.specimen-card-status {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--accent-seaglass-dark);
}

.status-dot {
  width: 7px;
  height: 7px;
  background-color: var(--accent-seaglass);
  border-radius: 50%;
}

.specimen-diagram-svg {
  width: 100%;
  height: auto;
  max-height: 280px;
  display: block;
}

/* Diagram One-shot Animation */
.diagram-line-anim {
  stroke-dasharray: 200;
  stroke-dashoffset: 200;
  animation: lineDraw 1.8s ease-out forwards;
}

.diagram-pulse {
  animation: pulseDot 2s ease-in-out forwards;
}

@keyframes lineDraw {
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes pulseDot {
  0% { r: 3px; opacity: 0.4; }
  50% { r: 6px; opacity: 1; }
  100% { r: 4px; opacity: 0.9; }
}

@media (prefers-reduced-motion: reduce) {
  .diagram-line-anim {
    animation: none;
    stroke-dashoffset: 0;
  }
  .diagram-pulse {
    animation: none;
  }
}

.specimen-annotations {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: 1rem;
  padding-top: 0.75rem;
  border-top: var(--border-hairline);
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.annotation-item {
  background-color: var(--bg-mineral);
  padding: 0.5rem;
  border: var(--border-hairline);
}

.annotation-label {
  color: #66706F;
  display: block;
  font-size: 0.7rem;
}

.annotation-val {
  font-weight: 600;
  color: var(--text-volcanic);
}

/* Section Styling */
.section-padding {
  padding: 4rem 0;
  border-bottom: var(--border-hairline);
}

/* Advantages Specimen Layout */
.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 900px) {
  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.advantage-card {
  border: var(--border-hairline);
  background-color: #FFFFFF;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  position: relative;
}

.advantage-card::before {
  content: attr(data-specimen-id);
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent-seaglass-dark);
  background-color: var(--bg-limestone);
  padding: 0.15rem 0.4rem;
  border: var(--border-hairline);
}

.advantage-icon {
  margin-bottom: 1.25rem;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: var(--border-hairline);
  background-color: var(--bg-mineral);
  color: var(--text-volcanic);
}

/* Global Nodes Section (Horizontal Region Samples) */
.nodes-disclaimer {
  background-color: var(--bg-limestone);
  border-left: 3px solid var(--accent-seaglass-dark);
  padding: 0.85rem 1.25rem;
  font-size: 0.875rem;
  margin-bottom: 2rem;
  font-family: var(--font-mono);
}

.nodes-container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.node-row {
  border: var(--border-hairline);
  background-color: #FFFFFF;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 768px) {
  .node-row {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.node-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.node-code {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.35rem 0.75rem;
  background-color: var(--bg-limestone);
  border: var(--border-hairline);
  min-width: 80px;
  text-align: center;
}

.node-name {
  font-weight: 700;
  font-size: 1.1rem;
}

.node-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #55605F;
}

.node-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.5rem;
  background-color: var(--bg-mineral);
  border: var(--border-hairline);
}

/* Use Cases Paired Scenario Sheets */
.use-cases-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 900px) {
  .use-cases-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.scenario-sheet {
  border: var(--border-hairline-strong);
  background-color: #FFFFFF;
  padding: 2rem;
  display: flex;
  flex-direction: column;
}

.scenario-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 2px solid var(--text-volcanic);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
}

.scenario-title {
  font-size: 1.35rem;
}

.service-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: 1rem;
}

.service-chip {
  padding: 0.6rem 0.85rem;
  border: var(--border-hairline);
  background-color: var(--bg-mineral);
  font-family: var(--font-mono);
  font-size: 0.825rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.service-name {
  font-weight: 700;
  color: var(--text-volcanic);
}

.service-desc {
  font-size: 0.75rem;
  color: #66706F;
  font-family: var(--font-body);
}

/* Pricing Section */
.pricing-disclaimer {
  background-color: var(--bg-limestone);
  border: var(--border-hairline);
  padding: 1rem 1.25rem;
  font-size: 0.85rem;
  margin-bottom: 2rem;
  font-family: var(--font-mono);
  color: #4A5352;
}

.pricing-table-wrapper {
  overflow-x: auto;
  border: var(--border-hairline-strong);
  background-color: #FFFFFF;
  margin-bottom: 1.5rem;
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.pricing-table th, .pricing-table td {
  padding: 1rem 1.25rem;
  border-bottom: var(--border-hairline);
  border-right: var(--border-hairline);
}

.pricing-table th {
  background-color: var(--bg-limestone);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-volcanic);
}

.pricing-table td:last-child, .pricing-table th:last-child {
  border-right: none;
}

.price-val {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--text-volcanic);
}

.placeholder-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #7A8584;
  font-style: italic;
}

/* SEO Article Cards (3/2/1 Layout) */
.seo-articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .seo-articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .seo-articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  border: var(--border-hairline);
  background-color: #FFFFFF;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.article-card:hover {
  border-color: var(--text-volcanic);
  transform: translateY(-2px);
}

.article-card-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-seaglass-dark);
  margin-bottom: 0.65rem;
}

.article-card-title {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.article-card-title a {
  text-decoration: none;
  color: var(--text-volcanic);
}

.article-card-title a:hover {
  color: var(--accent-seaglass-dark);
}

.article-card-desc {
  font-size: 0.875rem;
  color: #55605F;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-link {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-volcanic);
}

.article-card-link::after {
  content: "→";
}

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .testimonials-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.testimonial-card {
  border: var(--border-hairline);
  background-color: #FFFFFF;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  position: relative;
}

.testimonial-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.testimonial-author {
  font-weight: 700;
}

.testimonial-tag {
  font-size: 0.7rem;
  color: #6D7776;
  background-color: var(--bg-limestone);
  padding: 0.15rem 0.4rem;
  border: var(--border-hairline);
}

.testimonial-body {
  font-size: 0.925rem;
  line-height: 1.6;
  color: #3F4847;
}

/* FAQ Accordion */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  border: var(--border-hairline);
  background-color: #FFFFFF;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 1.25rem 1.5rem;
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-volcanic);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.faq-icon {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  transition: transform 0.25s ease;
}

.faq-item.is-open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0 1.5rem 1.25rem;
  font-size: 0.95rem;
  color: #454E4D;
  border-top: var(--border-hairline);
  padding-top: 1rem;
}

.faq-item.is-open .faq-answer {
  display: block;
}

/* Article Detail Layout */
.article-header {
  padding: 3rem 0 2rem;
  border-bottom: var(--border-hairline);
  background-color: var(--bg-limestone);
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #66706F;
  margin-bottom: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.breadcrumb a {
  color: var(--text-volcanic);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb-separator {
  color: #99A1A0;
}

.article-content {
  padding: 3rem 0;
  max-width: 840px;
  margin: 0 auto;
}

.article-body {
  font-size: 1rem;
  line-height: 1.85;
  color: #2E3635;
}

.article-body h2 {
  margin-top: 2.5rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: var(--border-hairline);
}

.article-body h3 {
  margin-top: 1.75rem;
  margin-bottom: 0.85rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body blockquote {
  border-left: 3px solid var(--accent-seaglass-dark);
  background-color: var(--bg-limestone);
  padding: 1rem 1.25rem;
  margin: 1.75rem 0;
  font-style: italic;
  font-family: var(--font-heading);
}

.article-cta-box {
  border: var(--border-hairline-strong);
  background-color: #FFFFFF;
  padding: 1.75rem;
  margin: 2.5rem 0;
  text-align: center;
}

.related-articles {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: var(--border-hairline-strong);
}

/* Footer */
.site-footer {
  margin-top: auto;
  background-color: var(--text-volcanic);
  color: var(--bg-mineral);
  padding: 3.5rem 0 2rem;
  border-top: var(--border-hairline);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.5fr repeat(3, 1fr);
  }
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-seaglass);
  margin-bottom: 1.25rem;
}

.footer-col p {
  color: #B0B8B7;
  font-size: 0.875rem;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 0.65rem;
}

.footer-col ul a {
  color: #D5DDDC;
  text-decoration: none;
  font-size: 0.9rem;
}

.footer-col ul a:hover {
  color: var(--accent-seaglass);
  text-decoration: underline;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #909A99;
  text-align: center;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    text-align: left;
  }
}

/* Utility classes */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 2rem; }