/* ===================================
   BMS-SC - style.css
   Ultra premium, inspiré BMS.com
   =================================== */

:root {
  --bms-blue: #2d355e;
  --bms-purple: #9239a7;
  --bms-light: #f5f6fa;
  --bms-grey: #6c7480;
  --bms-white: #fff;
  --bms-gradient: linear-gradient(90deg, #2d355e 65%, #9239a7 100%);
  --bms-accent: #00b3e6;
  --radius: 18px;
  --shadow: 0 8px 32px 0 rgba(45,53,94,0.12);
  --shadow-lg: 0 14px 50px 0 rgba(146,57,167,0.08);
  --transition: 0.23s cubic-bezier(.55,.06,.68,.19);
}

/* Base */
html, body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', 'Roboto', Arial, sans-serif;
  background: var(--bms-light);
  color: var(--bms-blue);
  font-size: 18px;
  line-height: 1.62;
}

/* Utilities */
.container {
  width: 92%;
  max-width: 1320px;
  margin: 0 auto;
}

/* Header */
.header {
  background: var(--bms-white);
  box-shadow: 0 2px 14px 0 rgba(45,53,94,0.07);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-flex {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5em;
  font-weight: 700;
  color: var(--bms-blue);
  text-decoration: none;
  letter-spacing: 2px;
}

.logo img {
  height: 44px;
  width: 44px;
  border-radius: 50%;
  background: var(--bms-gradient);
  padding: 3px;
}

.main-nav ul {
  list-style: none;
  display: flex;
  gap: 38px;
  margin: 0; padding: 0;
}

.main-nav a {
  text-decoration: none;
  color: var(--bms-blue);
  font-size: 1.07em;
  font-weight: 500;
  position: relative;
  padding: 2px 2px;
  transition: color var(--transition);
}
.main-nav a:after {
  content: "";
  display: block;
  margin: 4px auto 0 auto;
  height: 3px;
  width: 0%;
  background: var(--bms-purple);
  border-radius: 2px;
  transition: width var(--transition);
}
.main-nav a:hover,
.main-nav a:focus {
  color: var(--bms-purple);
}
.main-nav a:hover:after,
.main-nav a:focus:after {
  width: 60%;
}

/* Hero */
.hero {
  background: var(--bms-gradient), url('../assets/hero-bg.jpg') center/cover no-repeat;
  color: var(--bms-white);
  position: relative;
  min-height: 440px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(45,53,94,0.42);
  z-index: 1;
}
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 72px 12px 90px 12px;
}
.hero h1 {
  font-size: 2.65em;
  font-weight: 900;
  margin-bottom: 16px;
  letter-spacing: 1.5px;
}
.hero-highlight {
  color: var(--bms-accent);
  font-weight: 700;
  font-size: 0.8em;
  display: block;
  margin-top: 5px;
}
.hero p {
  font-size: 1.22em;
  margin-bottom: 32px;
  color: #e3f6ff;
}
.btn-primary {
  display: inline-block;
  padding: 15px 38px;
  border-radius: 99px;
  background: var(--bms-purple);
  color: var(--bms-white);
  font-size: 1.14em;
  text-decoration: none;
  font-weight: 700;
  box-shadow: var(--shadow);
  border: none;
  transition: background var(--transition), transform var(--transition);
  cursor: pointer;
  letter-spacing: 1px;
}
.btn-primary:hover, .btn-primary:focus {
  background: var(--bms-blue);
  transform: translateY(-2px) scale(1.035);
}

/* Sections génériques */
.home-section {
  padding: 70px 0;
  background: var(--bms-white);
}
.section-desc {
  color: var(--bms-grey);
  font-size: 1.1em;
  margin-bottom: 28px;
}

/* About */
.about-flex {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 50px;
}
.about-text {
  flex: 1 1 320px;
  font-size: 1.09em;
}
.about-img {
  flex: 0 1 330px;
}
.about-img img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* Research */
.research {
  background: var(--bms-light);
}
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 34px;
}
.card {
  background: var(--bms-white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 36px 26px;
  text-align: left;
  transition: transform var(--transition), box-shadow var(--transition);
  border-left: 6px solid var(--bms-purple);
}
.card:hover {
  transform: translateY(-6px) scale(1.035);
  box-shadow: var(--shadow-lg);
}
.card h3 {
  margin-top: 0;
  margin-bottom: 13px;
  color: var(--bms-purple);
  font-weight: 700;
  font-size: 1.16em;
}
.card p {
  margin: 0;
  color: var(--bms-blue);
}

/* Expertise */
.expertise-flex {
  display: flex;
  flex-wrap: wrap;
  gap: 55px;
  align-items: center;
}
.expertise-img {
  flex: 0 1 330px;
}
.expertise-img img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.expertise-text {
  flex: 1 1 320px;
  font-size: 1.07em;
}
.expertise-text ul {
  margin: 20px 0 0 18px;
  padding: 0;
  color: var(--bms-grey);
  font-size: 0.98em;
  line-height: 1.7;
}

/* Innovation */
.innovation {
  background: var(--bms-light);
}
.innovation-cards {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}
.innovation-card {
  flex: 1 1 260px;
  background: var(--bms-white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 22px;
  text-align: left;
  border-top: 5px solid var(--bms-accent);
  margin-bottom: 18px;
  transition: box-shadow var(--transition), transform var(--transition);
}
.innovation-card h3 {
  color: var(--bms-blue);
  font-size: 1.12em;
  font-weight: 700;
  margin-top: 0;
}
.innovation-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px) scale(1.03);
}

/* Contact */
.contact-flex {
  display: flex;
  flex-wrap: wrap;
  gap: 42px;
  align-items: flex-start;
}
.contact-info {
  flex: 1 1 340px;
  font-size: 1.04em;
}
.contact-form {
  flex: 0 1 350px;
  background: var(--bms-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 22px;
  display: flex;
  flex-direction: column;
  gap: 15px;
}
.contact-form h3 {
  margin: 0 0 13px 0;
  font-size: 1.09em;
  color: var(--bms-purple);
}
.contact-form input, .contact-form textarea {
  width: 100%;
  padding: 11px 15px;
  font-size: 1em;
  border: 1px solid #e1e2e9;
  border-radius: 8px;
  margin-bottom: 3px;
  background: var(--bms-white);
  resize: none;
  transition: border-color 0.15s;
}
.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--bms-purple);
  outline: none;
}

/* Footer */
.footer {
  background: var(--bms-blue);
  color: var(--bms-white);
  padding: 34px 0 20px 0;
  margin-top: 35px;
}
.footer-flex {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
}
.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15em;
  letter-spacing: 1.5px;
}
.footer-logo img {
  height: 35px;
  width: 35px;
  border-radius: 50%;
  background: var(--bms-gradient);
  padding: 2px;
}
.footer-links {
  display: flex;
  gap: 24px;
}
.footer-links a {
  color: var(--bms-white);
  text-decoration: none;
  font-size: 1em;
  opacity: 0.89;
  transition: opacity 0.15s;
}
.footer-links a:hover, .footer-links a:focus {
  opacity: 1;
  text-decoration: underline;
}
.footer-copyright {
  flex-basis: 100%;
  text-align: right;
  font-size: 0.98em;
  color: #b2c4e0;
  margin-top: 15px;
}

/* Responsive */
@media (max-width: 1100px) {
  .about-flex, .expertise-flex, .contact-flex {
    flex-direction: column;
    gap: 35px;
  }
  .footer-flex {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
  .main-nav ul {
    gap: 22px;
  }
}
@media (max-width: 700px) {
  .hero h1 { font-size: 2em; }
  .container { width: 98%; }
  .about-img, .expertise-img { margin-bottom: 18px; }
  .footer-logo span { display: none; }
  .footer-copyright { text-align: center; }
  .research-grid, .innovation-cards {
    grid-template-columns: 1fr;
    flex-direction: column;
    gap: 18px;
  }
}
@media (max-width: 540px) {
  .header-flex, .footer-flex { flex-direction: column; gap: 8px; }
  .hero-content { padding: 44px 5px 60px 5px; }
  .card, .innovation-card, .contact-form { padding: 20px 8px; }
  .logo img { height: 34px; width: 34px; }
}

/* Divers */
::-webkit-scrollbar { width: 8px; background: #eee;}
::-webkit-scrollbar-thumb { background: var(--bms-blue); border-radius: 8px;}
::selection { background: var(--bms-purple); color: #fff;}
/* MENU BURGER - Responsive */
.burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 34px; height: 34px;
  background: none; border: none;
  cursor: pointer;
  margin-right: 12px;
  z-index: 1010;
}
.burger span {
  display: block;
  height: 4px;
  width: 100%;
  background: var(--bms-purple);
  border-radius: 2px;
  transition: all .24s cubic-bezier(.76,.09,.68,.84);
}
@media (max-width: 800px) {
  .main-nav ul {
    display: none;
    flex-direction: column;
    background: var(--bms-white);
    position: absolute;
    top: 64px; right: 12px;
    box-shadow: 0 4px 24px #0001;
    border-radius: 12px;
    padding: 18px 14px 18px 18px;
    z-index: 1009;
    min-width: 170px;
  }
  .main-nav ul.open {display: flex;}
  .burger {display: flex;}
}
.burger.open span:nth-child(1) {transform: translateY(9px) rotate(45deg);}
.burger.open span:nth-child(2) {opacity:0;}
.burger.open span:nth-child(3) {transform: translateY(-9px) rotate(-45deg);}