/* SOS PREPA MATHS – Domaine 7 : Aéronautique, spatial et systèmes de transport
   Mêmes classes que electronique.css / mecanique.css / automatique.css / genie-industriel-systemes.css / genie-civil-construction.css.
   Charte graphique partagée entre tous les domaines. */

:root {
  --dark-navy: #172033;
  --accent-orange: #f28c28;
  --orange-light: #fff4e6;
  --bg: #f7f8fa;
  --bg-grey: #eef1f5;
  --text: #2b3445;
  --radius: 12px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: 'Poppins', sans-serif; background: var(--bg); color: var(--text); line-height: 1.7; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
.container { width: min(1180px, 92%); margin: 0 auto; }
:focus-visible { outline: 3px solid var(--accent-orange); outline-offset: 2px; }

/* Barre du haut */
.top-bar { background: var(--dark-navy); padding: 8px 0; }
.top-bar-content { display: flex; justify-content: flex-end; }
.social-links { display: flex; gap: 16px; }
.social-links a { color: #fff; font-size: .9rem; }
.social-links a:hover { color: var(--accent-orange); }

/* En-tête */
.main-header { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.06); position: sticky; top: 0; z-index: 10; }
.header-container { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 14px 0; flex-wrap: wrap; }
.logo { font-weight: 800; font-size: 1.3rem; color: var(--dark-navy); }
.logo-orange { color: var(--accent-orange); }
.main-nav ul { display: flex; gap: 20px; flex-wrap: wrap; }
.main-nav a { font-size: .85rem; font-weight: 500; color: var(--dark-navy); }
.main-nav a:hover { color: var(--accent-orange); }

/* Titre du domaine */
.domain-intro { background: var(--dark-navy); color: #fff; text-align: center; padding: 72px 6% 64px; }
.domain-number { display: inline-block; background: var(--accent-orange); color: #fff; font-weight: 700; font-size: .85rem; letter-spacing: 1px; padding: 6px 18px; border-radius: 30px; margin-bottom: 20px; }
.domain-intro h1 { font-size: clamp(2rem, 5vw, 3.4rem); font-weight: 800; line-height: 1.15; }
.domain-intro h1 span { display: block; color: var(--accent-orange); }
.intro-lead { max-width: 720px; margin: 22px auto 0; font-size: 1.1rem; opacity: .92; }

/* Sections d'information */
.info-section { width: min(960px, 92%); margin: 32px auto; background: #fff; padding: 36px 40px; border-radius: var(--radius); box-shadow: 0 2px 12px rgba(23,32,51,.06); }
.info-section h2 { font-size: 1.25rem; font-weight: 700; color: var(--dark-navy); margin-bottom: 18px; }
.info-section h2 i { color: var(--accent-orange); margin-right: 10px; }
.info-section p { margin-bottom: 14px; }
.info-section p:last-child { margin-bottom: 0; }

.important-box { background: var(--orange-light); border-left: 5px solid var(--accent-orange); padding: 18px 22px; border-radius: 8px; margin-top: 22px; }
.important-box strong { display: block; color: var(--dark-navy); margin-bottom: 6px; }
.question-box { background: var(--dark-navy); color: #fff; padding: 24px 28px; border-radius: var(--radius); margin-top: 24px; }
.question-box p { margin-bottom: 8px; }

.actions-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 14px; margin-top: 18px; }
.action-card { background: var(--bg); border: 1px solid #e3e7ee; border-radius: 10px; padding: 20px 16px; text-align: center; font-weight: 500; }
.action-card i { display: block; font-size: 1.5rem; color: var(--accent-orange); margin-bottom: 10px; }

.problem-list { display: grid; gap: 10px; }
.problem-list div { display: flex; gap: 12px; align-items: flex-start; }
.problem-list i { color: var(--accent-orange); margin-top: 6px; }

.systems-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 12px; }
.systems-grid div { background: var(--bg-grey); border-radius: 8px; padding: 12px 14px; text-align: center; font-weight: 500; color: var(--dark-navy); }

.sectors { display: flex; flex-wrap: wrap; gap: 10px; margin: 8px 0 4px; }
.sectors span { background: var(--dark-navy); color: #fff; padding: 6px 18px; border-radius: 30px; font-size: .9rem; }

/* Frontières avec les domaines voisins */
.frontier-list { display: grid; gap: 10px; }
.frontier-list div { display: grid; grid-template-columns: 1fr 1.4fr; gap: 16px; background: var(--bg); border-radius: 8px; padding: 12px 16px; align-items: center; }
.frontier-list strong { color: var(--dark-navy); }

/* SPÉCIFIQUE DOMAINE 5 : distinction Génie industriel / Ingénierie des systèmes */
.distinction-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; margin-top: 8px; }
.distinction-card { background: var(--bg); border: 1px solid #e3e7ee; border-radius: 10px; padding: 22px 24px; }
.distinction-card h3 { color: var(--accent-orange); font-size: 1rem; font-weight: 700; margin-bottom: 10px; }
.distinction-card p { font-size: .93rem; margin-bottom: 10px; }
.distinction-card p:last-child { margin-bottom: 0; }
.distinction-chain { display: block; font-weight: 600; color: var(--dark-navy); background: #fff; border-radius: 6px; padding: 8px 12px; margin-top: 10px; font-size: .85rem; }

/* Spécialités */
.specialties { background: var(--bg-grey); padding: 64px 0; }
.section-title { text-align: center; width: min(760px, 92%); margin: 0 auto 40px; }
.small-title { color: var(--accent-orange); font-weight: 700; font-size: .85rem; letter-spacing: 1px; }
.section-title h2 { font-size: 1.8rem; color: var(--dark-navy); margin: 6px 0 10px; }
.specialties-grid { width: min(1180px, 92%); margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }
.specialties-grid--single { grid-template-columns: minmax(300px, 520px); justify-content: center; }
.specialty-card { position: relative; display: flex; flex-direction: column; background: #fff; border-radius: var(--radius); padding: 28px 26px; box-shadow: 0 2px 10px rgba(23,32,51,.07); transition: transform .2s, box-shadow .2s; }
a.specialty-card:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(23,32,51,.13); }
.specialty-number { font-size: 1.9rem; font-weight: 800; color: var(--accent-orange); line-height: 1; margin-bottom: 12px; }
.specialty-card h3 { font-size: 1.05rem; color: var(--dark-navy); margin-bottom: 8px; line-height: 1.35; }
.specialty-card p { font-size: .92rem; flex: 1; margin-bottom: 14px; }
.specialty-card > span { color: var(--accent-orange); font-weight: 600; font-size: .9rem; }
.specialty-card--complementary { background: transparent; border: 2px dashed var(--accent-orange); box-shadow: none; }
.specialty-number--badge { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 50%; background: var(--accent-orange); color: #fff; font-size: 1.3rem; }
.complementary-title { text-align: center; margin: 48px 0 20px; font-weight: 600; color: var(--dark-navy); }
.bridges { margin-bottom: 4px; }
.bridges li { font-size: .92rem; padding: 3px 0; }

.back-link { text-align: center; margin: 40px 0; }
.back-link a { display: inline-block; background: var(--dark-navy); color: #fff; padding: 12px 28px; border-radius: 30px; font-weight: 500; }
.back-link a:hover { background: var(--accent-orange); }

footer { background: var(--dark-navy); color: #fff; text-align: center; padding: 22px; font-size: .9rem; }

@media (max-width: 720px) {
  .info-section { padding: 26px 22px; }
  .frontier-list div { grid-template-columns: 1fr; gap: 4px; }
  .main-nav ul { gap: 12px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .specialty-card { transition: none; }
}