/**
 * header.css
 * Styles pour le header sticky, navigation, menu mobile hamburger.
 * Utilise les conventions BEM : header / header__nav / header__link--active
 */

/* ── Header principal ─────────────────────────────────────────────────────── */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: height var(--duration-fast) var(--ease-out-expo),
              box-shadow var(--duration-fast) var(--ease-out-expo);
  will-change: height;
}

.header--compact {
  height: var(--header-height-compact);
  box-shadow: var(--shadow-sm);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--space-lg);
}

/* ── Logo ─────────────────────────────────────────────────────────────────── */
.header__logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: var(--gradient-signature);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
  z-index: 1001;
}

/* ── Navigation desktop ───────────────────────────────────────────────────── */
.header__nav {
  display: none;
}

.header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.header__link {
  position: relative;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--duration-fast);
  padding-block: var(--space-xs);
}

.header__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--gradient-signature);
  border-radius: 1px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--ease-out-expo);
}

.header__link:hover::after,
.header__link--active::after {
  transform: scaleX(1);
}

.header__link:hover {
  color: var(--color-accent);
}

/* ── Hamburger (mobile) ───────────────────────────────────────────────────── */
.header__hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  z-index: 1001;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

.header__hamburger-line {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--duration-normal) var(--ease-out-expo),
              opacity var(--duration-fast);
  will-change: transform, opacity;
}

/* Hamburger → croix */
.header__hamburger--open .header__hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.header__hamburger--open .header__hamburger-line:nth-child(2) {
  opacity: 0;
}

.header__hamburger--open .header__hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Menu mobile overlay ──────────────────────────────────────────────────── */
.header__mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  background-color: var(--color-bg);
  transform: translateX(100%);
  transition: transform var(--duration-normal) var(--ease-out-expo);
  will-change: transform;
}

.header__mobile-menu--open {
  transform: translateX(0);
}

.header__mobile-link {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text);
  transition: color var(--duration-fast);
}

.header__mobile-link:hover,
.header__mobile-link--active {
  color: var(--color-accent);
}

/* ── Desktop breakpoint ───────────────────────────────────────────────────── */
@media (min-width: 768px) {
  .header__nav {
    display: block;
  }

  .header__hamburger {
    display: none;
  }

  .header__mobile-menu {
    display: none;
  }
}