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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", system-ui, sans-serif;
  background:#0f172a ;
  color:#e5e7eb;
  line-height: 1.6;
}

/* HEADER */
.site-header {
  background:#111827 ;
  border-bottom: 1px solid #1e293b;
}

.header-content {
  max-width: 1100px;
  margin: auto;
  padding: 48px 24px;
  text-align: center;
}

.site-header h1 {
  font-size: 2.4rem;
  color: #38bdf8;
  margin-bottom: 8px;
align-items: center;
}

.author {
  color: #94a3b8;
  font-size: 1rem;
  margin-bottom: 28px;
}

/* NAVIGATION */
.nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  justify-content: center;
  gap: 16px;
  padding: 14px 20px;
  background: rgba(15, 23, 42, 0.9);
  border-bottom: 1px solid #1e293b;
  backdrop-filter: blur(6px);
}

.nav a {
  text-decoration: none;
  color: #e5e7eb;
  padding: 8px 14px;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.25s ease;
}

.nav a:hover,
.nav a.active {
  background: #38bdf8;
  color: #020617;
}


/* MAIN */
main {
  max-width: 1100px;
  margin: auto;
  padding: 60px 24px;
}

/*INTRO*/
.intro {
  background:#111827 ; 
  border: 1px solid #1e293b;
  border-radius: 14px;
  padding: 32px;
  margin-bottom: 48px;
}

.intro h2 {
  color: #22c55e;
  margin-bottom: 12px;
  font-size: 1.6rem;
text-align: center;
}

.intro p {
  color: #e5e7eb;
  max-width: 800px;
}

/*SECTIONS TP*/
.tp-section {
  background: #111827 ;
  border: 1px solid #1e293b;
  border-radius: 14px;
  padding: 28px;
  margin-bottom: 32px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.35);
  transition: transform 0.25s ease;
}

.tp-section:hover {
  transform: translateY(-6px);
}

.tp-section h3 {
  color: #38bdf8;
  font-size: 1.4rem;
  margin-bottom: 12px;
}

.tp-section p {
  color: #94a3b8;
  margin-bottom: 12px;
}

.tp-section strong {
  color: #e5e7eb;
}

/*BOUTONS EXERCICES */
.btn-exercice {
  display: inline-block;
  margin-top: 14px;
  padding: 12px 22px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 600;
  background: #38bdf8;
  color: #020617;
  transition: all 0.25s ease;
}

.btn-exercice:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(56,189,248,0.4);
}

/* ==========================
   FOOTER
========================== */
.site-footer {
  border-top: 1px solid #1e293b;
  margin-top: 60px;
  padding: 32px 20px;
  text-align: center;
  color: #94a3b8;
  font-size: 0.95rem;
}