:root{
  --bg:#f5f7fc;
  --bg-soft:#eef2f8;
  --card:#ffffff;
  --text:#1f2937;
  --muted:#667085;
  --line:#d9e0ea;
  --primary:#17306e;
  --primary-2:#2e5bb7;
  --shadow:0 18px 48px rgba(18, 37, 84, 0.12);
  --radius:26px;
  --container:min(1180px, 92%);
  --narrow:min(860px, 92%);
  --header-offset:96px;
}

*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  font-family:Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  overflow-x:hidden;
}
img{display:block;max-width:100%;height:auto;}
a{text-decoration:none;color:inherit;}
.container{width:var(--container);margin:0 auto;}
.narrow{width:var(--narrow);margin:0 auto;}

#auteur,#livres,#contact{scroll-margin-top:var(--header-offset);}

.site-header{
  position:sticky;
  top:0;
  z-index:20;
  background:rgba(245,247,252,0.94);
  backdrop-filter:blur(14px);
  border-bottom:1px solid rgba(23,48,110,0.08);
}
.header-inner{
  min-height:78px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
}
.brand{
  font-size:1.12rem;
  font-weight:700;
  color:var(--primary);
}
.main-nav{display:flex;gap:28px;}
.main-nav a{color:var(--primary);font-weight:600;}
.main-nav a:hover,.brand:hover{opacity:0.82;}

.hero-premium{
  padding:74px 0 84px;
  background:
    radial-gradient(circle at 8% 12%, rgba(46,91,183,0.16), transparent 24%),
    radial-gradient(circle at 88% 16%, rgba(23,48,110,0.08), transparent 18%),
    linear-gradient(180deg, #f8faff 0%, #f5f7fc 100%);
}
.hero-premium-grid{
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(340px,520px);
  gap:56px;
  align-items:center;
}
.hero-kicker,.section-label,.book-type{
  display:inline-block;
  font-size:0.84rem;
  font-weight:700;
  text-transform:uppercase;
  letter-spacing:0.08em;
  color:var(--primary-2);
}
.hero-copy h1{
  margin:16px 0 18px;
  font-size:clamp(2.7rem,5vw,4.9rem);
  line-height:1.02;
  color:var(--primary);
  max-width:700px;
}
.hero-intro{
  max-width:620px;
  color:var(--muted);
  font-size:1.08rem;
}
.hero-tags{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin-top:22px;
}
.hero-tags span{
  background:#fff;
  color:var(--primary);
  border:1px solid var(--line);
  border-radius:999px;
  padding:9px 14px;
  font-size:0.92rem;
  font-weight:700;
}
.hero-actions,.book-actions{
  display:flex;
  flex-wrap:wrap;
  gap:14px;
  margin-top:28px;
}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  padding:14px 22px;
  border:none;
  border-radius:999px;
  font-weight:700;
  transition:0.2s ease;
  cursor:pointer;
  text-align:center;
}
.btn:hover{transform:translateY(-1px);}
.btn-primary{
  background:linear-gradient(135deg,var(--primary),var(--primary-2));
  color:#fff;
  box-shadow:0 10px 24px rgba(23,48,110,0.18);
}
.btn-secondary{
  background:#fff;
  color:var(--primary);
  border:1px solid var(--line);
}

.hero-books-stack{
  position:relative;
  min-height:560px;
  display:flex;
  align-items:center;
  justify-content:center;
}
.book-panel{
  position:absolute;
  width:min(100%,320px);
  background:#fff;
  border-radius:24px;
  padding:14px;
  box-shadow:var(--shadow);
}
.book-panel img{
  width:100%;
  aspect-ratio:3/4;
  object-fit:cover;
  border-radius:18px;
}
.book-panel.back{
  transform:translate(-78px, 16px) rotate(-7deg);
  opacity:0.96;
}
.book-panel.front{
  transform:translate(58px, -10px) rotate(6deg);
  z-index:2;
}

.intro-section,.author-section,.books-section,.quote-section,.contact-section{padding:90px 0;}
.intro-box,.author-grid,.book-card,.contact-card{background:var(--card);box-shadow:var(--shadow);}
.intro-box{
  border-radius:var(--radius);
  padding:40px;
  text-align:center;
  font-size:1.08rem;
  color:#445065;
}
.author-grid{
  display:grid;
  grid-template-columns:0.85fr 1.15fr;
  gap:36px;
  border-radius:var(--radius);
  padding:34px;
  align-items:center;
}
.author-photo img{
  width:100%;
  min-height:360px;
  object-fit:cover;
  border-radius:22px;
  box-shadow:0 12px 28px rgba(18,37,84,0.10);
}
.author-content h2,.section-heading h2{
  margin:12px 0 16px;
  font-size:clamp(2rem,4vw,3rem);
  line-height:1.1;
  color:var(--primary);
}
.author-content p,.section-heading p{
  color:var(--muted);
  font-size:1.05rem;
}
.author-content p + p{margin-top:14px;}
.section-heading{max-width:780px;margin:0 auto 42px;}
.section-heading.center{text-align:center;}

.books-grid{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:30px;
}
.book-card{
  border-radius:var(--radius);
  overflow:hidden;
  display:flex;
  flex-direction:column;
  height:100%;
}
.book-card.featured{border:1px solid rgba(46,91,183,0.14);}
.book-cover{padding:26px 26px 0;}
.book-cover img{
  width:100%;
  max-width:260px;
  margin:0 auto;
  border-radius:18px;
  box-shadow:0 12px 28px rgba(0,0,0,0.12);
  aspect-ratio:3/4;
  object-fit:cover;
}
.book-content{
  padding:26px 28px 30px;
  display:flex;
  flex-direction:column;
  flex:1;
}
.book-content h3{
  margin:12px 0 14px;
  font-size:1.6rem;
  line-height:1.2;
  color:var(--primary);
}
.book-content p{color:var(--muted);}
.book-actions{margin-top:auto;}

.quote-section{background:var(--bg-soft);}
.quote-section blockquote{
  text-align:center;
  font-size:clamp(1.6rem,3vw,2.3rem);
  line-height:1.35;
  color:var(--primary);
  font-weight:700;
}

.contact-card{
  border-radius:var(--radius);
  padding:34px;
}
.alert{
  padding:14px 16px;
  border-radius:14px;
  margin-bottom:18px;
  font-weight:700;
}
.alert.success{background:#e8f7ee;color:#1f6a3c;}
.alert.error{background:#fdecec;color:#a12626;}
.contact-form{display:grid;gap:18px;}
.form-row{display:grid;gap:8px;}
.form-row label{font-weight:700;color:var(--primary);}
.form-row input,.form-row textarea{
  width:100%;
  padding:15px 16px;
  border:1px solid var(--line);
  border-radius:16px;
  font-size:1rem;
  background:#fff;
  color:var(--text);
  appearance:none;
}
.form-row textarea{min-height:170px;resize:vertical;}
.form-submit{padding-top:6px;}

.site-footer{padding:28px 0 40px;}
.footer-inner{text-align:center;color:var(--muted);}

@media (max-width: 980px){
  .hero-premium-grid,.author-grid,.books-grid{grid-template-columns:1fr;}
  .hero-premium{padding:56px 0 64px;}
  .hero-books-stack{
    min-height:420px;
    margin-bottom:10px;
  }
  .hero-copy{
    order:2;
  }
  .intro-section,.author-section,.books-section,.quote-section,.contact-section{padding:70px 0;}
  .intro-box,.author-grid,.contact-card{padding:28px;}
  .author-photo img{min-height:260px;}
}

@media (max-width: 640px){
  .header-inner{
    flex-direction:column;
    justify-content:center;
    padding:14px 0;
  }
  .main-nav{
    justify-content:center;
    flex-wrap:wrap;
    gap:16px;
  }
  .hero-copy h1{font-size:2.3rem;}
  .hero-actions,.book-actions{
    flex-direction:column;
    align-items:stretch;
  }
  .btn{width:100%;}
  .book-panel{
    width:min(86%,280px);
  }
  .book-panel.back{
    transform:translate(-34px, 18px) rotate(-6deg);
  }
  .book-panel.front{
    transform:translate(30px, -8px) rotate(5deg);
  }
  .book-content h3{font-size:1.35rem;}
}