@charset "utf-8";
/* CSS Document */

body {
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
  background: #f3f5f7;
  color: #222222;
  line-height: 1.7;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

header {
  border-bottom: 1px solid #dddddd;
  background: #fcfcfd;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 0;
  flex-wrap: wrap;
  gap: 12px;
}

.logo {
  font-size: 1.05rem;
  letter-spacing: 0.06em;
  color: #1f2a36;
  text-decoration: none;
  transition: color 0.2s ease;
}

.logo:hover {
  color: #111111;
}

nav {
  margin-left: auto;
}

nav a {
  text-decoration: none;
  color: #555555;
  margin-left: 24px;
  font-size: 0.95rem;
  transition: color 0.2s ease;
  padding-bottom: 4px;
}

nav a:hover {
  color: #1f2a36;
}

nav a.active {
  color: #1f2a36;
  border-bottom: 2px solid #1f2a36;
}

.hero {
  padding: 70px 0 60px 0;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  margin: 0 0 12px 0;
  font-weight: normal;
  color: #1f2a36;
}

.hero h2 {
  font-size: 1.25rem;
  margin: 0 0 40px 0;
  font-weight: normal;
  color: #666666;
}

.cover {
  max-width: 360px;
  margin: 0 auto 42px auto;
}

.cover img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid #d8d8d8;
}

.intro {
  max-width: 640px;
  margin: 0 auto;
  text-align: left;
  font-size: 1.08rem;
  color: #2b2b2b;
}

.intro p {
  margin: 0 0 18px 0;
}

.section {
  padding: 70px 0;
  border-top: 1px solid #e2e2e2;
}

.section h3 {
  font-size: 1.7rem;
  font-weight: normal;
  margin: 0 0 36px 0;
  color: #1f2a36;
}

.books,
.structure-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card {
  border: 1px solid #e3e6ea;
  padding: 24px;
  background: #f8fafc;
  transition: border-color 0.2s ease, transform 0.2s ease;
  min-height: 220px;
}

.card:hover {
  border-color: #cfd8e2;
  transform: translateY(-2px);
}

.card h4 {
  margin: 0 0 12px 0;
  font-size: 1.08rem;
  font-weight: normal;
  color: #111111;
}

.card p {
  margin: 0 0 16px 0;
  color: #555555;
  font-size: 0.98rem;
  line-height: 1.65;
}

.card a {
  display: inline-block;
  margin-top: 14px;
  color: #1f2a36;
  font-weight: 500;
  text-decoration: none;
}

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

.orientation {
  max-width: 760px;
  font-size: 1.06rem;
  color: #2b2b2b;
  line-height: 1.75;
}

.orientation p {
  margin: 0 0 18px 0;
}

footer {
  border-top: 1px solid #dddddd;
  padding: 32px 0 42px 0;
  font-size: 0.95rem;
  color: #666666;
  text-align: center;
  background: #fcfcfd;
}

footer a {
  color: #444444;
  text-decoration: none;
  margin: 0 10px;
  transition: color 0.2s ease;
}

footer a:hover {
  color: #1f2a36;
  text-decoration: underline;
}

/* HERO UB-2 */

.hero-ub2 {
  padding: 80px 0 70px 0;
}

.hero-ub2-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 420px);
  gap: 56px;
  align-items: center;
}

.hero-ub2-content {
  text-align: left;
  max-width: 700px;
  padding-top: 8px;
}

.hero-ub2-kicker {
  margin: 0 0 16px 0;
  font-size: 0.98rem;
  color: #5f6b76;
}

.hero-ub2-content h1 {
  margin: 0 0 18px 0;
  font-size: 3rem;
  font-weight: normal;
  color: #1f2a36;
  text-align: left;
}

.hero-ub2-content h2 {
  margin: 0 0 28px 0;
  font-size: 1.25rem;
  font-weight: normal;
  color: #666666;
  text-align: left;
}

.hero-ub2-intro {
  max-width: 760px;
}

.hero-ub2-intro p:first-child {
  margin-top: 8px;
}

.hero-ub2-intro p {
  margin: 0 0 18px 0;
  font-size: 1.08rem;
  color: #2b2b2b;
  line-height: 1.75;
}

.hero-ub2-actions-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 28px;
}

.hero-ub2-actions-row {
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
}

.hero-ub2-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 142px;
  padding: 12px 18px;
  border: 1px solid #cfd8e2;
  background: #f8fafc;
  color: #1f2a36;
  text-decoration: none;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.hero-ub2-btn:hover {
  background: #eef3f7;
  border-color: #b9c8d6;
  color: #1f2a36;
  text-decoration: none;
}

.hero-ub2-btn-primary {
  background: #1f2a36;
  border-color: #1f2a36;
  color: #ffffff;
}

.hero-ub2-btn-primary:hover {
  background: #2a3745;
  border-color: #2a3745;
  color: #ffffff;
}

.hero-ub2-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 24px;
  font-size: 0.96rem;
  color: #66707a;
}

.hero-ub2-visual {
  display: flex;
  justify-content: center;
  padding-top: 20px;
}

.hero-ub2-cover {
  width: 100%;
  max-width: 330px;
  margin-top: 20px;
}

.hero-ub2-cover img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid #d4dbe2;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.06);
  max-width: 320px;
}

/* FOOTER UB-2 */

.site-footer-ub2 {
  border-top: 1px solid #dddddd;
  background: #fcfcfd;
  padding: 28px 0;
  margin-top: 0;
}

.site-footer-ub2-inner {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 10px;
  text-align: center;
}

.site-footer-ub2-left,
.site-footer-ub2-center,
.site-footer-ub2-right {
  display: flex;
  align-items: center;
}

.site-footer-ub2-left p,
.site-footer-ub2-right p {
  margin: 0;
  font-size: 0.95rem;
  color: #666666;
}

.site-footer-ub2-center {
   display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

.site-footer-ub2-center a,
.site-footer-ub2-center span {
  font-size: 0.95rem;
  color: #666666;
}

.site-footer-ub2-center a {
  text-decoration: none;
  transition: color 0.2s ease;
}

.site-footer-ub2-center a:hover {
  color: #1f2a36;
  text-decoration: underline;
}

/* RESPONSIVE */

@media (max-width: 900px) {

  .hero-ub2-grid {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .hero-ub2-content {
    order: 2;
    max-width: 100%;
  }

  .hero-ub2-visual {
    order: 1;
    justify-content: flex-start;
    padding-top: 0;
  }

  .hero-ub2-content h1,
  .hero-ub2-content h2 {
    text-align: left;
  }

}

@media (max-width: 768px) {

  .site-footer-ub2-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .site-footer-ub2-center {
    justify-content: flex-start;
  }

  .topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 0;
    flex-wrap: wrap;
    gap: 12px;
  }

  nav a {
    margin: 0 18px 0 0;
  }

  .hero {
    padding: 55px 0 45px 0;
  }

  .hero h1 {
    font-size: 2.3rem;
  }

  .hero h2 {
    font-size: 1.08rem;
  }

  .cover {
    max-width: 300px;
  }

  .section {
    padding: 55px 0;
  }

  .section h3 {
    font-size: 1.75rem;
    font-weight: 500;
  }

  .intro,
  .orientation {
    font-size: 1rem;
  }

  .hero-ub2 {
    padding: 60px 0 55px 0;
  }

  .hero-ub2-content h1 {
    font-size: 2.3rem;
  }

  .hero-ub2-content h2 {
    font-size: 1.08rem;
  }

  .hero-ub2-intro p {
    font-size: 1rem;
  }

  .hero-ub2-actions-row {
    gap: 8px;
  }

  .hero-ub2-btn {
    min-width: 0;
    width: auto;
  }

  .hero-ub2-btn + .hero-ub2-btn {
    margin-left: 0;
  }

  .hero-ub2-meta {
    gap: 14px;
    margin-top: 22px;
  }

  .site-footer-ub2-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer-ub2-center {
    justify-content: flex-start;
  }

}

/* ==========================================
   DIAGRAMMES
========================================== */

.diagram-gallery {
  display: grid;
  gap: 40px;
}

.diagram-card {
  background: #ffffff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,.08);
}

.diagram-card img {
  display: block;
  max-width: 700px;
  width: 100%;
  height: auto;
  margin: 0 auto;
}

.diagram-content {
  padding: 24px;
}

.diagram-content h4 {
  margin-bottom: 12px;
}

.diagram-content p {
  margin: 0;
}

.diagram-actions {
  margin-top: 16px;
}

.diagram-actions a {
  color: #1f2a36;
  text-decoration: none;
  font-weight: 500;
}

.diagram-actions a:hover {
  text-decoration: underline;
}

.download-btn {
  display: inline-block;
  padding: 10px 18px;
  background: #1f2a36;
  color: #ffffff !important;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 500;
  transition: background 0.2s ease;
}

.download-btn:hover {
  background: #2f3d4c;
  text-decoration: none;
  color: #ffffff !important;
}