@charset "UTF-8";
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&family=Noto+Sans+JP:wght@400;500;600;700&display=swap');

/* ==========================================================================
   Design System: Technical Architecture & Academic Blueprint Specification
   (Zero AI Rounded Aesthetics, Sharp Technical Grid & Mono-line Engineering)
   ========================================================================== */

:root {
  /* High-Contrast Technical Slate & Crisp Cobalt Navy Palette */
  --color-primary: #0062cc;
  --color-primary-dark: #0b1a30;
  --color-primary-light: #edf5fd;
  --color-accent: #0284c7;
  --color-accent-sub: #1d4ed8;
  
  --color-bg-page: #e7edf3;
  --color-bg-surface: #ffffff;
  --color-bg-muted: #f1f6fa;
  --color-bg-subtle: #e4eef7;
  
  --color-text-main: #0b1a30;
  --color-text-body: #1e293b;
  --color-text-sub: #334155;
  --color-text-muted: #5a6a80;
  
  --color-border-strong: #0b1a30;
  --color-border-main: #9cb0c5;
  --color-border-light: #c8d5e2;
  --color-border-hover: #0062cc;

  /* Typography Stacks */
  --font-sans: 'Inter', 'Helvetica Neue', 'Arial', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', 'Noto Sans JP', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Consolas', 'Menlo', monospace;
  --max-width: 1120px;
  
  /* Strictly Zero Corner Radius */
  --radius-zero: 0px;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  
  /* Technical Transition */
  --transition-fast: 0.15s ease-in-out;
}

/* ==========================================================================
   Reset & Global Typography
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* Strict Zero Rounded Look */
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg-page);
  color: var(--color-text-body);
  line-height: 1.75;
  letter-spacing: -0.005em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary-dark);
  text-decoration: underline;
  text-decoration-color: var(--color-border-main);
  text-underline-offset: 3px;
  transition: all var(--transition-fast);
}

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

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

/* ==========================================================================
   Layout: Site Container & Framing
   ========================================================================== */

.site-wrapper {
  max-width: var(--max-width);
  margin: 2rem auto 4rem;
  background-color: var(--color-bg-surface);
  border: 1px solid var(--color-border-main);
  border-top: 4px solid var(--color-primary-dark);
  box-shadow: none; /* No Float Shadow */
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   Header: Academic & Technical Title Bar
   ========================================================================== */

.site-header {
  background-color: #ffffff;
  padding: 1.75rem 2.25rem;
  border-bottom: 1px solid var(--color-border-main);
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.header-title-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.header-title-group h1 {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-text-sub);
  letter-spacing: 0.02em;
}

.header-lab-name {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  text-decoration: none;
  display: inline-flex;
  flex-direction: column;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.header-lab-name .en-sub {
  font-family: var(--font-sans);
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-top: 0.3rem;
}

.header-lab-name:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.header-logo {
  display: flex;
  align-items: center;
}

.univ-logo {
  height: 44px;
  width: auto;
  display: block;
  transition: opacity var(--transition-fast);
}

.univ-logo:hover {
  opacity: 0.85;
}

/* ==========================================================================
   Navigation: Technical Tab Matrix
   ========================================================================== */

.site-nav {
  background-color: #ffffff;
  border-bottom: 1px solid var(--color-border-main);
  padding: 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
}

.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  width: 100%;
}

.nav-item {
  flex: 1;
  border-right: 1px solid var(--color-border-light);
}

.nav-item:last-child {
  border-right: none;
}

.nav-item a {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 0.5rem;
  color: var(--color-text-sub);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 600;
  background-color: #ffffff;
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-item a:hover {
  color: var(--color-primary-dark);
  background-color: var(--color-bg-muted);
  border-bottom-color: var(--color-border-main);
}

.nav-item a.active {
  color: var(--color-primary-dark);
  background-color: var(--color-bg-subtle);
  border-bottom: 2px solid var(--color-primary-dark);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border-main);
  color: var(--color-primary-dark);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.75rem 1rem;
  cursor: pointer;
  width: 100%;
  text-align: left;
}

/* ==========================================================================
   Main Layout & Content Structure
   ========================================================================== */

.main-layout {
  display: flex;
  flex: 1;
  background-color: #ffffff;
}

.main-content {
  flex: 1;
  padding: 2.75rem 3rem;
  min-width: 0;
}

.sidebar {
  width: 280px;
  background-color: var(--color-bg-muted);
  border-left: 1px solid var(--color-border-main);
  padding: 2.5rem 1.75rem;
  flex-shrink: 0;
}

/* ==========================================================================
   Hero Banner & Technical Abstract Specification
   ========================================================================== */

.page-title-banner {
  background-color: var(--color-bg-muted);
  border: 1px solid var(--color-border-main);
  border-left: 4px solid var(--color-primary-dark);
  padding: 1.75rem 2rem;
  margin-bottom: 2rem;
}

.page-title-banner h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  letter-spacing: -0.015em;
  line-height: 1.5;
  margin: 0;
}

/* ==========================================================================
   Concept Visual: Diagram Frame
   ========================================================================== */

.hero-concept-image {
  margin: 1.5rem 0 2rem 0;
  border: 1px solid var(--color-border-main);
  background-color: #ffffff;
  box-shadow: none;
}

.hero-concept-image .concept-visual {
  width: 100%;
  height: auto;
  display: block;
}

.hero-concept-image .image-caption {
  padding: 0.65rem 1rem;
  background-color: var(--color-bg-muted);
  border-top: 1px solid var(--color-border-main);
  font-size: 0.82rem;
  color: var(--color-text-sub);
  text-align: center;
  margin: 0;
  font-weight: 500;
}

/* ==========================================================================
   Section Headings: Technical Specification Style
   ========================================================================== */

.section-header-group {
  margin-top: 3rem;
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.section-header-group:first-child {
  margin-top: 0;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary);
  display: block;
}

h2.section-heading, h3.section-heading {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  letter-spacing: -0.01em;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-primary-dark);
}

/* ==========================================================================
   Lists: Technical Specifications & Intro Cards
   ========================================================================== */

.content-intro-list {
  list-style: none;
  padding: 0;
  margin-bottom: 2.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.content-intro-list > li {
  position: relative;
  padding: 1.15rem 1.35rem 1.15rem 1.5rem;
  background-color: var(--color-bg-muted);
  border: 1px solid var(--color-border-main);
  border-left: 3px solid var(--color-primary-dark);
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--color-text-body);
}

.content-intro-list ul {
  margin-top: 0.6rem;
  padding-left: 1.25rem;
  list-style-type: square;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.content-intro-list ul li {
  color: var(--color-text-sub);
  font-size: 0.92rem;
}

/* Topics Technical List */
.topics-list {
  list-style: none;
  padding: 0;
  margin-bottom: 2.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.topics-list > li {
  background-color: #ffffff;
  border: 1px solid var(--color-border-main);
  padding: 1.25rem 1.5rem;
  font-weight: 600;
  font-size: 0.96rem;
  color: var(--color-primary-dark);
  transition: border-color var(--transition-fast);
}

.topics-list > li:hover {
  border-color: var(--color-border-strong);
}

.topics-list > li > ul {
  list-style: none;
  padding-left: 0;
  margin-top: 0.75rem;
  font-weight: 400;
  font-size: 0.92rem;
  color: var(--color-text-body);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.topics-list > li > ul > li {
  position: relative;
  padding-left: 1.25rem;
  line-height: 1.65;
}

.topics-list > li > ul > li::before {
  content: "■";
  position: absolute;
  left: 0.15rem;
  top: 0;
  color: var(--color-primary);
  font-size: 0.75rem;
}

.topics-list ul ul {
  list-style: none;
  padding-left: 0.5rem;
  margin-top: 0.35rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.topics-list ul ul > li {
  position: relative;
  padding-left: 1.15rem;
  color: var(--color-text-sub);
  font-size: 0.88rem;
}

.topics-list ul ul > li::before {
  content: "–";
  position: absolute;
  left: 0.2rem;
  top: 0;
  color: var(--color-text-muted);
}

/* News Container */
.news-container {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.news-card {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 0.85rem 1.15rem;
  background-color: #ffffff;
  border: 1px solid var(--color-border-light);
  border-left: 2px solid var(--color-border-main);
  transition: all var(--transition-fast);
}

.news-card:hover {
  border-color: var(--color-border-strong);
  border-left-color: var(--color-primary);
  background-color: var(--color-bg-muted);
}

.news-date-badge {
  font-family: var(--font-mono);
  color: var(--color-text-sub);
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
  letter-spacing: 0.02em;
  background-color: var(--color-bg-subtle);
  padding: 0.15rem 0.5rem;
  border: 1px solid var(--color-border-main);
}

.news-body {
  font-size: 0.92rem;
  color: var(--color-text-main);
  flex: 1;
}

/* ==========================================================================
   Academic & Engineering Data Tables (Three-Line Table Style)
   ========================================================================= */

.table-wrapper {
  overflow-x: auto;
  margin: 1.5rem 0 2rem;
  border: 1px solid var(--color-border-main);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  background-color: #ffffff;
}

.data-table th {
  background-color: var(--color-bg-muted);
  color: var(--color-primary-dark);
  font-weight: 700;
  text-align: left;
  padding: 0.85rem 1rem;
  border-bottom: 2px solid var(--color-primary-dark);
  white-space: nowrap;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.data-table td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text-body);
  vertical-align: middle;
  line-height: 1.6;
}

.data-table tr:last-child td {
  border-bottom: 2px solid var(--color-primary-dark);
}


.data-table .col-center {
  text-align: center;
}

.data-table .col-year {
  font-family: var(--font-mono);
  text-align: center;
  white-space: nowrap;
  font-weight: 600;
  color: var(--color-primary-dark);
  font-size: 0.85rem;
}

.badge-tag {
  font-family: var(--font-mono);
  display: inline-block;
  padding: 0.15rem 0.45rem;
  background-color: var(--color-bg-subtle);
  color: var(--color-text-sub);
  font-size: 0.76rem;
  font-weight: 500;
  border: 1px solid var(--color-border-main);
  text-decoration: none;
}

.badge-tag:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
  border-color: var(--color-primary-dark);
}

/* Callout Box */
.notice-box {
  background-color: var(--color-bg-muted);
  border: 1px solid var(--color-border-main);
  border-left: 3px solid var(--color-primary);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  font-size: 0.92rem;
}

.notice-box h4 {
  font-size: 0.95rem;
  color: var(--color-primary-dark);
  margin-bottom: 0.5rem;
  font-weight: 700;
}

/* Image Framing */
.image-frame {
  margin: 1.5rem 0;
  text-align: center;
  background: #ffffff;
  padding: 0.5rem;
  border: 1px solid var(--color-border-main);
}

/* Generic Card Box (Flat Specification) */
.card-box {
  background-color: #ffffff;
  border: 1px solid var(--color-border-main);
  padding: 1.75rem;
  margin-bottom: 1.75rem;
  transition: border-color var(--transition-fast);
}

.card-box:hover {
  border-color: var(--color-border-strong);
}

/* ==========================================================================
   Sidebar: Technical Navigation & Index Panel
   ========================================================================== */

.sidebar-section {
  margin-bottom: 2.25rem;
}

.sidebar-title {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary-dark);
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-primary-dark);
}

.sidebar-links {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.sidebar-links li a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background-color: #ffffff;
  border: 1px solid var(--color-border-main);
  padding: 0.65rem 0.85rem;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--color-text-body);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.sidebar-links li a::after {
  content: "↗";
  font-family: var(--font-sans);
  color: var(--color-text-muted);
  font-size: 0.85rem;
  transition: color var(--transition-fast);
}

.sidebar-links li a:hover {
  border-color: var(--color-border-strong);
  color: var(--color-primary-dark);
  background-color: var(--color-bg-subtle);
}

.sidebar-links li a:hover::after {
  color: var(--color-primary-dark);
}

.sidebar-info-card {
  background-color: #ffffff;
  border: 1px solid var(--color-border-main);
  padding: 1.25rem;
  font-size: 0.84rem;
  color: var(--color-text-body);
  line-height: 1.6;
}

.sidebar-info-card h4 {
  font-size: 0.9rem;
  color: var(--color-primary-dark);
  margin-bottom: 0.4rem;
  font-weight: 700;
}

/* ==========================================================================
   Page Top Link
   ========================================================================== */

.pagetop-link {
  text-align: right;
  margin-top: 2rem;
  font-size: 0.84rem;
}

.pagetop-link a {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.82rem;
  color: var(--color-text-sub);
  text-decoration: none;
  padding: 0.35rem 0.75rem;
  background: #ffffff;
  border: 1px solid var(--color-border-main);
  transition: all var(--transition-fast);
}

.pagetop-link a:hover {
  color: var(--color-primary-dark);
  border-color: var(--color-border-strong);
  background-color: var(--color-bg-muted);
}

/* ==========================================================================
   Footer: Technical Monolithic Bar
   ========================================================================== */

.site-footer {
  background-color: var(--color-primary-dark);
  color: #94a3b8;
  padding: 2rem 2.25rem;
  text-align: center;
  font-size: 0.82rem;
  border-top: 1px solid var(--color-border-strong);
}

.site-footer p {
  margin: 0;
  letter-spacing: 0.02em;
}

/* ==========================================================================
   Responsive: Mobile Technical Adaptation
   ========================================================================== */

@media (max-width: 900px) {
  .site-wrapper {
    margin: 0;
    border: none;
    border-top: 4px solid var(--color-primary-dark);
  }
}

@media (max-width: 768px) {
  .site-header {
    padding: 1.25rem;
  }
  
  .header-info {
    text-align: left;
    width: 100%;
  }

  .site-nav {
    padding: 0.5rem 1.25rem;
  }

  .nav-toggle {
    display: block;
  }

  .nav-menu {
    display: none;
    flex-direction: column;
    padding: 0.5rem 0;
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-item {
    border-right: none;
    border-bottom: 1px solid var(--color-border-light);
  }

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

  .nav-item a {
    justify-content: flex-start;
    padding: 0.75rem 0.85rem;
    border-bottom: none;
    border-left: 2px solid transparent;
  }

  .nav-item a.active {
    border-bottom: none;
    border-left: 2px solid var(--color-primary-dark);
  }

  .main-layout {
    flex-direction: column;
  }

  .main-content {
    padding: 1.75rem 1.25rem;
  }

  .sidebar {
    width: 100%;
    border-left: none;
    border-top: 1px solid var(--color-border-main);
    padding: 1.75rem 1.25rem;
  }
}