/* ==========================================================================
   base — reset, root variables, typography, links, images
   ========================================================================== */
:root {
  --color-deep-blue: #0b2a3c;
  --color-region-blue: #1e4d63;
  --color-info-cyan: #3b7d8c;
  --color-amber: #e8b44b;
  --color-paper: #f2ede4;
  --color-aux-gray: #73919b;
  --color-text: #1f2d33;
  --color-text-light: #5b6b72;
  --color-white: #ffffff;
  --color-border: #d8d2c8;
  --color-card-bg: #faf7f2;
  --color-table-head: #eef0ee;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", "Roboto Mono", Consolas, monospace;

  --container-width: 1140px;
  --header-top-height: 52px;
  --header-bottom-height: 56px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-paper);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border: 0;
}

a {
  color: var(--color-region-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  color: var(--color-deep-blue);
  line-height: 1.4;
}

h1 {
  font-size: 2rem;
}

h2 {
  font-size: 1.5rem;
}

h3 {
  font-size: 1.125rem;
}

p {
  margin-bottom: 1rem;
}

figure {
  margin: 0;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   layout — header, footer, main, sidebar shell
   ========================================================================== */

/* ---- header ---- */
.site-header {
  background-color: var(--color-deep-blue);
  color: var(--color-white);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(11, 42, 60, 0.18);
}

.header-top {
  background-color: var(--color-deep-blue);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.header-top-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-top-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  color: var(--color-white);
  text-decoration: none;
}

.brand-link:hover {
  color: var(--color-amber);
  text-decoration: none;
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.02em;
}

.header-position {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.75);
  margin: 0;
  text-align: right;
}

.header-bottom {
  background-color: var(--color-region-blue);
}

.header-bottom-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-bottom-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.main-nav {
  flex: 1;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
}

.nav-list li {
  margin: 0;
}

.nav-link {
  display: inline-block;
  padding: 10px 16px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-white);
  background-color: rgba(255, 255, 255, 0.12);
  text-decoration: none;
}

.nav-link.is-current {
  color: var(--color-white);
  background-color: rgba(232, 180, 75, 0.22);
  font-weight: 600;
}

.nav-cta {
  background-color: var(--color-amber);
  color: var(--color-deep-blue);
  font-weight: 600;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
}

.nav-cta:hover {
  background-color: #dda83a;
  color: var(--color-deep-blue);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 12px;
  width: 48px;
  height: 48px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
  border-radius: 2px;
}

/* ---- footer ---- */
.site-footer {
  background-color: var(--color-deep-blue);
  color: rgba(255, 255, 255, 0.82);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 20px 28px;
}

.footer-updates {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-update-col h3 {
  color: var(--color-white);
  font-size: 1rem;
  margin-bottom: 12px;
  font-weight: 600;
}

.footer-update-col ul li {
  margin-bottom: 8px;
}

.footer-update-col ul li a {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.875rem;
}

.footer-update-col ul li a:hover {
  color: var(--color-amber);
}

.footer-nav {
  padding: 32px 0 24px;
}

.footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
}

.footer-nav ul li a {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.875rem;
}

.footer-nav ul li a:hover {
  color: var(--color-amber);
  text-decoration: none;
}

.footer-boundary {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.55);
  line-height: 1.6;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  margin-bottom: 12px;
}

.footer-copyright {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.45);
  margin: 0;
}

/* ---- main layout ---- */
.site-main {
  flex: 1;
}

.inner-main {
  padding: 0 0 64px;
  background-color: var(--color-paper);
}

/* breadcrumb */
.breadcrumb {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px 20px 0;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--color-aux-gray);
}

.breadcrumb a {
  color: var(--color-info-cyan);
}

.breadcrumb a:hover {
  color: var(--color-deep-blue);
}

.breadcrumb-sep {
  color: var(--color-aux-gray);
}

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* page header */
.page-header {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 20px 20px 28px;
}

.page-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin: 0;
  line-height: 1.35;
}

/* page title area (archives / collaborate / notebook) */
.page-title-area {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px 20px 0;
}

.page-title-area p {
  font-size: 1rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.7;
}

/* page heading (services / faq / about) */
.page-heading {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px 20px 36px;
}

.page-heading .page-intro,
.page-heading p {
  font-size: 1rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.7;
}

/* layout shell — two column with sidebar on right */
.layout-shell {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 40px;
  align-items: start;
}

.layout-shell .main-content {
  min-width: 0;
}

.layout-shell .sidebar,
.layout-shell .sidebar-area {
  min-width: 0;
}

/* sidebar-right variant */
.layout-shell.sidebar-right {
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 44px;
}

/* sidebar-left — aside comes first */
.sidebar-left .layout-shell {
  grid-template-columns: 280px minmax(0, 1fr);
}

.sidebar-left .layout-shell .main-content {
  order: 2;
}

.sidebar-left .layout-shell .sidebar,
.sidebar-left .layout-shell .sidebar-area {
  order: 1;
}

/* page-layout for services */
.page-layout {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 40px;
  align-items: start;
}

.page-layout .main-content {
  min-width: 0;
}

.page-layout .sidebar {
  min-width: 0;
}

/* ==========================================================================
   components — buttons, cards, tables, faq, sidebar blocks
   ========================================================================== */

/* ---- buttons ---- */
.btn-primary,
.btn-secondary {
  display: inline-block;
  padding: 12px 28px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-align: center;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--color-amber);
  color: var(--color-deep-blue);
}

.btn-primary:hover {
  background-color: #dda83a;
  color: var(--color-deep-blue);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-info-cyan);
  border-color: var(--color-info-cyan);
}

.btn-secondary:hover {
  background-color: var(--color-info-cyan);
  color: var(--color-white);
  text-decoration: none;
  transform: translateY(-1px);
}

/* ---- sidebar ---- */
.sidebar,
.sidebar-area {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.sidebar-card,
.sidebar-block {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sidebar-card h2,
.sidebar-block h2 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-amber);
}

.sidebar-card p,
.sidebar-block p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 12px;
  line-height: 1.7;
}

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar-links a {
  font-size: 0.875rem;
  color: var(--color-info-cyan);
}

.sidebar-links a:hover {
  color: var(--color-deep-blue);
}

.sidebar-link {
  display: inline-block;
  font-size: 0.875rem;
  color: var(--color-info-cyan);
  font-weight: 500;
  margin-top: 4px;
}

.sidebar-link:hover {
  color: var(--color-deep-blue);
  text-decoration: underline;
}

/* toc block */
.toc-block ul {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc-block ul li a {
  display: block;
  padding: 6px 0;
  font-size: 0.875rem;
  color: var(--color-info-cyan);
  border-left: 2px solid transparent;
  padding-left: 12px;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.toc-block ul li a:hover {
  border-left-color: var(--color-amber);
  color: var(--color-deep-blue);
  text-decoration: none;
}

/* related block */
.related-block ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.related-block ul li a {
  font-size: 0.875rem;
  color: var(--color-info-cyan);
  line-height: 1.6;
}

.related-block ul li a:hover {
  color: var(--color-deep-blue);
}

/* boundary block */
.boundary-block p {
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
  line-height: 1.7;
  margin: 0;
}

/* ---- section head ---- */
.section-head {
  margin-bottom: 32px;
}

.section-head h2 {
  font-size: 1.625rem;
  color: var(--color-deep-blue);
  margin-bottom: 8px;
}

.section-head p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin: 0;
  max-width: 720px;
}

/* ---- service cards (home) ---- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.service-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  position: relative;
}

.service-card:hover {
  box-shadow: 0 8px 24px rgba(11, 42, 60, 0.1);
  transform: translateY(-4px);
}

.service-marker {
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background-color: var(--color-info-cyan);
  margin-bottom: 16px;
}

.service-card:nth-child(2) .service-marker {
  background-color: var(--color-amber);
}

.service-card:nth-child(3) .service-marker {
  background-color: var(--color-region-blue);
}

.service-card:nth-child(4) .service-marker {
  background-color: var(--color-aux-gray);
}

.service-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 8px;
}

.service-card p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 16px;
  flex: 1;
}

.card-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-info-cyan);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.card-link:hover {
  color: var(--color-deep-blue);
  text-decoration: none;
}

.card-link::after {
  content: "→";
  font-size: 1rem;
  transition: transform var(--transition-fast);
}

.card-link:hover::after {
  transform: translateX(3px);
}

/* ---- process steps (home) ---- */
.process-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.process-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
}

.process-figure img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.process-steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.process-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 16px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition-fast);
}

.process-step:hover {
  box-shadow: 0 4px 16px rgba(11, 42, 60, 0.08);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--color-deep-blue);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.process-step:nth-child(2) .step-num {
  background-color: var(--color-region-blue);
}

.process-step:nth-child(3) .step-num {
  background-color: var(--color-info-cyan);
}

.process-step:nth-child(4) .step-num {
  background-color: var(--color-amber);
  color: var(--color-deep-blue);
}

.step-body h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 4px;
}

.step-body p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.6;
}

/* ---- collab preview (home) ---- */
.collab-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.collab-step {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: box-shadow var(--transition-fast);
}

.collab-step:hover {
  box-shadow: 0 4px 16px rgba(11, 42, 60, 0.08);
}

.step-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-amber);
  background-color: rgba(232, 180, 75, 0.12);
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 12px;
  font-family: var(--font-mono);
}

.collab-step h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 6px;
}

.collab-step p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.6;
}

.collab-more {
  margin-top: 28px;
  text-align: center;
}

/* ---- updates (home) ---- */
.updates-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
}

.update-col h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-amber);
}

.update-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.update-list li {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  transition: box-shadow var(--transition-fast);
}

.update-list li:hover {
  box-shadow: 0 2px 8px rgba(11, 42, 60, 0.06);
}

.update-list li a {
  font-size: 0.9375rem;
  color: var(--color-text);
  font-weight: 500;
}

.update-list li a:hover {
  color: var(--color-info-cyan);
  text-decoration: none;
}

.update-tag {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--color-info-cyan);
  background-color: rgba(59, 125, 140, 0.1);
  padding: 2px 8px;
  border-radius: 12px;
  margin-right: 8px;
  font-family: var(--font-mono);
}

/* ---- faq (home summary + faq page) ---- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-item summary {
  padding: 18px 24px;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-deep-blue);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: background-color var(--transition-fast);
}

.faq-item summary:hover {
  background-color: var(--color-card-bg);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 1.375rem;
  font-weight: 400;
  color: var(--color-info-cyan);
  flex-shrink: 0;
  line-height: 1;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  padding: 0 24px 20px;
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin: 0;
}

.faq-more {
  margin-top: 24px;
  text-align: center;
}

/* ---- capability table (services) ---- */
.capability-table-section {
  margin-bottom: 48px;
}

.capability-table-section h2 {
  font-size: 1.375rem;
  margin-bottom: 8px;
}

.capability-table-section > p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 20px;
}

.table-wrapper {
  overflow-x: auto;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.capability-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.capability-table th,
.capability-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

.capability-table thead th {
  background-color: var(--color-table-head);
  font-weight: 600;
  color: var(--color-deep-blue);
  white-space: nowrap;
}

.capability-table tbody tr:last-child td {
  border-bottom: 0;
}

.capability-table tbody tr:hover td {
  background-color: rgba(232, 180, 75, 0.06);
}

.capability-table td:first-child {
  font-weight: 600;
  color: var(--color-deep-blue);
  white-space: nowrap;
}

/* ---- data panel (services) ---- */
.data-panel-section {
  margin-bottom: 40px;
}

.data-panel-section h2 {
  font-size: 1.375rem;
  margin-bottom: 20px;
}

.panel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: center;
}

.panel-figure {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.panel-image {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.panel-text p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 12px;
}

.panel-text p:last-child {
  margin-bottom: 0;
}

/* ---- archive (archives page) ---- */
.archive-section {
  margin-bottom: 56px;
}

.archive-head {
  margin-bottom: 28px;
}

.archive-head h2 {
  font-size: 1.375rem;
  margin-bottom: 6px;
}

.archive-head p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin: 0;
}

.archive-year-group {
  margin-bottom: 28px;
}

.archive-year-group h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-amber);
  display: flex;
  align-items: center;
  gap: 8px;
}

.archive-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.archive-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: box-shadow var(--transition-fast);
}

.archive-item:hover {
  box-shadow: 0 2px 8px rgba(11, 42, 60, 0.06);
}

.archive-item a {
  font-size: 0.9375rem;
  color: var(--color-text);
  font-weight: 500;
  flex: 1;
}

.archive-item a:hover {
  color: var(--color-info-cyan);
  text-decoration: none;
}

.archive-tag {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--color-info-cyan);
  background-color: rgba(59, 125, 140, 0.1);
  padding: 2px 10px;
  border-radius: 12px;
  font-family: var(--font-mono);
  white-space: nowrap;
}

/* ---- case (archives page) ---- */
.case-section {
  margin-bottom: 48px;
}

.case-head {
  margin-bottom: 24px;
}

.case-head h2 {
  font-size: 1.375rem;
  margin-bottom: 6px;
}

.case-head p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin: 0;
}

.case-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 24px;
}

.case-figure {
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.case-figure img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.case-body {
  display: flex;
  flex-direction: column;
}

.case-body h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 12px;
}

.case-steps {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.case-steps li {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.7;
  padding-left: 20px;
  position: relative;
}

.case-steps li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background-color: var(--color-amber);
}

/* ---- related links ---- */
.related-links {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 20px 0;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-deep-blue);
}

.related-links-item {
  font-size: 0.875rem;
  color: var(--color-info-cyan);
  padding: 8px 16px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.related-links-item:hover {
  background-color: var(--color-info-cyan);
  color: var(--color-white);
  text-decoration: none;
}

/* ---- flow steps (collaborate) ---- */
.cooperation-flow-section {
  margin-bottom: 48px;
}

.cooperation-flow-section h2 {
  font-size: 1.375rem;
  margin-bottom: 8px;
}

.cooperation-flow-section > p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.flow-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.flow-step-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  position: relative;
  transition: box-shadow var(--transition-fast);
}

.flow-step-card:hover {
  box-shadow: 0 4px 16px rgba(11, 42, 60, 0.08);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background-color: var(--color-deep-blue);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.flow-step-card:nth-child(2) .step-number,
.flow-step-card:nth-child(5) .step-number {
  background-color: var(--color-region-blue);
}

.flow-step-card:nth-child(3) .step-number,
.flow-step-card:nth-child(6) .step-number {
  background-color: var(--color-info-cyan);
}

.flow-step-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 6px;
}

.flow-step-card p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.6;
  margin: 0;
}

.step-deliverable {
  display: inline-block;
  margin-top: 10px;
  font-size: 0.75rem;
  color: var(--color-amber);
  background-color: rgba(232, 180, 75, 0.1);
  padding: 3px 10px;
  border-radius: 12px;
  font-family: var(--font-mono);
}

/* ---- materials (collaborate) ---- */
.materials-section {
  margin-bottom: 40px;
}

.materials-section h2 {
  font-size: 1.375rem;
  margin-bottom: 8px;
}

.materials-section > p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.materials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 28px;
}

.material-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.material-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 8px;
}

.material-card p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin: 0;
}

.content-figure {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-top: 20px;
}

.content-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.content-figure figcaption {
  padding: 12px 16px;
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
  background-color: var(--color-white);
}

/* ---- notebook ---- */
.latest-notes-section {
  margin-bottom: 48px;
}

.latest-notes-section h2 {
  font-size: 1.375rem;
  margin-bottom: 20px;
}

.note-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.note-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  transition: box-shadow var(--transition-fast);
}

.note-item:hover {
  box-shadow: 0 4px 16px rgba(11, 42, 60, 0.08);
}

.note-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
}

.note-date {
  font-family: var(--font-mono);
}

.note-status {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--color-info-cyan);
  background-color: rgba(59, 125, 140, 0.1);
  padding: 2px 10px;
  border-radius: 12px;
}

.note-item h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 6px;
}

.note-item p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.6;
}

/* note article */
.note-article {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 40px;
  margin-bottom: 40px;
}

.note-article h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 16px;
}

.note-article-intro {
  font-size: 1rem;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--color-border);
}

.note-article h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-top: 28px;
  margin-bottom: 12px;
  padding-left: 12px;
  border-left: 3px solid var(--color-amber);
}

.note-article p {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.note-figure {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin: 24px 0;
}

.note-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.note-figure figcaption {
  padding: 10px 16px;
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
}

/* related notes */
.related-notes {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-top: 40px;
}

.related-notes h2 {
  font-size: 1.125rem;
  margin-bottom: 16px;
}

.related-notes ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.related-notes ul li a {
  font-size: 0.9375rem;
  color: var(--color-info-cyan);
  line-height: 1.6;
}

.related-notes ul li a:hover {
  color: var(--color-deep-blue);
}

/* ---- faq page ---- */
.faq-section {
  margin-bottom: 48px;
}

.section-title {
  font-size: 1.375rem;
  margin-bottom: 24px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-amber);
}

.faq-group {
  margin-bottom: 32px;
}

.faq-group-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 14px;
  padding-left: 12px;
  border-left: 3px solid var(--color-info-cyan);
}

.faq-group .faq-item {
  margin-bottom: 10px;
}

/* self check */
.self-check-section {
  margin-bottom: 40px;
}

.self-check-content {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
}

.self-check-content > p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 16px;
}

.check-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 16px;
}

.check-list li {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
  padding-left: 28px;
  position: relative;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-info-cyan);
  font-weight: 700;
}

.self-check-content > p:last-child {
  margin-bottom: 0;
}

.self-check-content a {
  font-weight: 600;
}

/* faq media */
.faq-media {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 40px;
}

.faq-media img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.faq-media figcaption {
  padding: 10px 16px;
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
}

/* faq side note */
.faq-side-note {
  background-color: var(--color-card-bg);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: 20px 0;
  margin-bottom: 0;
}

.faq-side-note .container {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.faq-side-note p {
  margin: 0;
}

.faq-side-note a {
  font-size: 0.875rem;
  color: var(--color-info-cyan);
  font-weight: 500;
}

/* ---- about page ---- */
.platform-positioning {
  margin-bottom: 48px;
}

.positioning-copy h2 {
  font-size: 1.375rem;
  margin-bottom: 16px;
}

.positioning-copy p {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.positioning-figure {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-top: 24px;
}

.positioning-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

.positioning-figure figcaption {
  padding: 10px 16px;
  font-size: 0.8125rem;
  color: var(--color-aux-gray);
}

.service-principles {
  margin-bottom: 48px;
}

.service-principles h2 {
  font-size: 1.375rem;
  margin-bottom: 8px;
}

.section-intro {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.principles-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.principle-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  border-top: 3px solid var(--color-info-cyan);
  transition: box-shadow var(--transition-fast);
}

.principle-card:nth-child(2) {
  border-top-color: var(--color-amber);
}

.principle-card:nth-child(3) {
  border-top-color: var(--color-region-blue);
}

.principle-card:nth-child(4) {
  border-top-color: var(--color-aux-gray);
}

.principle-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 8px;
}

.principle-card p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin: 0;
}

.content-scope {
  margin-bottom: 40px;
}

.content-scope h2 {
  font-size: 1.375rem;
  margin-bottom: 8px;
}

.content-scope > p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 16px;
}

.scope-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 16px;
}

.scope-list li {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
  padding-left: 20px;
  position: relative;
}

.scope-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background-color: var(--color-amber);
}

.content-scope > p:last-child {
  margin-bottom: 0;
}

.content-scope a {
  font-weight: 600;
}

/* related links grid */
.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.related-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  display: block;
  transition: box-shadow var(--transition-fast), border-color var(--transition-fast);
}

.related-card:hover {
  box-shadow: 0 4px 16px rgba(11, 42, 60, 0.08);
  border-color: var(--color-amber);
  text-decoration: none;
}

.related-card h3 {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  margin-bottom: 6px;
}

.related-card p {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1.6;
}

/* ==========================================================================
   pages — home page specific sections
   ========================================================================== */

/* ---- hero ---- */
.hero-section {
  background-color: var(--color-deep-blue);
  color: var(--color-white);
  padding: 72px 0;
}

.hero-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-content h1 {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.35;
  margin-bottom: 16px;
}

.hero-lead {
  font-size: 1.0625rem;
  color: rgba(255, 255, 255, 0.82);
  line-height: 1.8;
  margin-bottom: 28px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-actions .btn-primary {
  background-color: var(--color-amber);
  color: var(--color-deep-blue);
}

.hero-actions .btn-secondary {
  border-color: rgba(255, 255, 255, 0.6);
  color: var(--color-white);
}

.hero-actions .btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: var(--color-white);
  color: var(--color-white);
}

.hero-figure {
  background-color: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.hero-figure img {
  width: 100%;
  height: 340px;
  object-fit: cover;
}

/* ---- intro ---- */
.intro-section {
  padding: 64px 0;
  background-color: var(--color-paper);
}

.intro-text p {
  font-size: 1rem;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
  max-width: 860px;
}

.intro-points {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 28px;
}

.point-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.point-value {
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-deep-blue);
  line-height: 1.3;
  margin-bottom: 6px;
}

.point-label {
  font-size: 0.875rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* ---- sections spacing ---- */
.services-section,
.process-section,
.collab-preview,
.updates-section,
.faq-summary {
  padding: 64px 0;
}

.services-section {
  background-color: var(--color-white);
}

.process-section {
  background-color: var(--color-paper);
}

.collab-preview {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-border);
}

.updates-section {
  background-color: var(--color-paper);
}

.faq-summary {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-border);
}

/* ==========================================================================
   pages — error page
   ========================================================================== */
.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  background-color: var(--color-paper);
}

.error-container {
  text-align: center;
  max-width: 560px;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 4rem;
  font-weight: 700;
  color: var(--color-amber);
  line-height: 1.2;
  margin-bottom: 16px;
}

.error-container h1 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 28px;
}

.error-home-link {
  display: inline-block;
  padding: 12px 32px;
  background-color: var(--color-amber);
  color: var(--color-deep-blue);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.error-home-link:hover {
  background-color: #dda83a;
  color: var(--color-deep-blue);
  text-decoration: none;
}

/* ==========================================================================
   responsive — breakpoints
   ========================================================================== */

/* ---- 1024px ---- */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .collab-steps {
    grid-template-columns: repeat(3, 1fr);
  }

  .principles-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .flow-steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .materials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .case-card {
    grid-template-columns: 1fr;
  }

  .case-figure img {
    height: 220px;
  }

  .layout-shell,
  .layout-shell.sidebar-right,
  .page-layout {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 28px;
  }
}

/* ---- 768px ---- */
@media (max-width: 768px) {
  .header-top-inner {
    padding: 0 16px;
  }

  .header-bottom-inner {
    padding: 0 16px;
  }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 0 16px;
  }

  .hero-section {
    padding: 56px 0;
  }

  .hero-content h1 {
    font-size: 1.75rem;
  }

  .hero-figure img {
    height: 260px;
  }

  .process-layout {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .process-figure img {
    height: 260px;
  }

  .updates-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .layout-shell,
  .layout-shell.sidebar-right,
  .page-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .layout-shell .sidebar,
  .layout-shell .sidebar-area,
  .page-layout .sidebar {
    order: 2;
  }

  .sidebar-left .layout-shell {
    grid-template-columns: 1fr;
  }

  .sidebar-left .layout-shell .main-content {
    order: 1;
  }

  .sidebar-left .layout-shell .sidebar {
    order: 2;
  }

  .panel-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .panel-image {
    height: 220px;
  }

  .case-card {
    grid-template-columns: 1fr;
  }

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

  .note-article {
    padding: 24px;
  }

  /* ---- mobile nav ---- */
  .nav-toggle {
    display: flex;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background-color: var(--color-region-blue);
    padding: 8px 16px 16px;
    gap: 4px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 24px rgba(11, 42, 60, 0.25);
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-list li {
    width: 100%;
  }

  .nav-link {
    display: block;
    padding: 14px 16px;
    font-size: 1rem;
    border-radius: var(--radius-sm);
  }

  .header-bottom {
    position: relative;
  }

  .header-bottom-inner {
    min-height: 56px;
  }
}

/* ---- 480px ---- */
@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .header-top-inner {
    padding: 0 16px;
  }

  .header-bottom-inner {
    padding: 0 16px;
  }

  .brand-name {
    font-size: 1.125rem;
  }

  .header-position {
    font-size: 0.75rem;
  }

  .hero-section {
    padding: 48px 0;
  }

  .hero-content h1 {
    font-size: 1.5rem;
  }

  .hero-lead {
    font-size: 0.9375rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    text-align: center;
  }

  .hero-figure img {
    height: 220px;
  }

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

  .collab-steps {
    grid-template-columns: 1fr;
  }

  .intro-points {
    grid-template-columns: 1fr;
  }

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

  .flow-steps {
    grid-template-columns: 1fr;
  }

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

  .footer-updates {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .footer-inner {
    padding: 36px 16px 24px;
  }

  .breadcrumb {
    padding: 16px 16px 0;
  }

  .page-header {
    padding: 16px 16px 24px;
  }

  .page-title {
    font-size: 1.5rem;
  }

  .page-title-area {
    padding: 16px 16px 0;
  }

  .page-heading {
    padding: 16px 16px 28px;
  }

  .related-links {
    padding: 24px 16px 0;
    gap: 10px;
  }

  .note-article {
    padding: 20px;
  }

  .note-figure img {
    height: 200px;
  }

  .panel-image {
    height: 200px;
  }

  .case-figure img {
    height: 200px;
  }

  .content-figure img {
    height: 200px;
  }

  .positioning-figure img {
    height: 220px;
  }

  .faq-media img {
    height: 200px;
  }

  .process-figure img {
    height: 220px;
  }

  .error-code {
    font-size: 3rem;
  }

  .error-main {
    padding: 60px 16px;
  }
}

/* ---- reduced motion ---- */
@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;
  }
}