/* 4.1. Header et Navigation principale */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: var(--color-header);
    z-index: var(--z-index-header);
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    display: flex;
}

.main-navigation {
    width: 100%;
    height: 100%;
}

.nav-container {
    width: 100%;
    height: 100%;
    display: grid;
    grid-template-columns: auto 1fr auto;
    padding: 0 10px;
}

/* Site Branding & Logo */
.site-branding {
    grid-column: 1;
    display: flex;
    align-items: center;
    padding-left: clamp(10px, 2vw, 20px);
}
.site-logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
}
.tt-logo {
    display: block;
    transition: opacity 0.2s ease;
}
.tt-logo-full {
    height: 40px;
    width: auto;
    color: var(--color-accent);
}
.tt-logo-compact {
    height: 36px;
    width: auto;
    color: var(--color-accent);
    display: none;
}
.tt-logo-frame {
    transition: stroke 0.3s ease;
}
.tt-logo text,
.tt-logo tspan {
    font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
}
.tt-logo-text-tech {
    font-size: 19px;
    font-weight: 700;
    letter-spacing: 3px;
}
.tt-logo-text-talk {
    font-size: 19px;
    font-weight: 400;
    letter-spacing: 3px;
}
.tt-logo-monogram {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: 2px;
}
.site-logo-link:hover .tt-logo {
    opacity: 0.8;
}

/* Hamburger Icon */
.hamburger-icon {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 24px;
    height: 24px;
}
.hamburger-icon span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-accent);
    border-radius: 1px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}
body.menu-active .hamburger-icon span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
body.menu-active .hamburger-icon span:nth-child(2) {
    opacity: 0;
}
body.menu-active .hamburger-icon span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Navigation Buttons */
.nav-buttons {
    grid-column: 2;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: clamp(10px, 2vw, 20px);
}

.nav-button {
    color: var(--color-text);
    text-decoration: none;
    transition: background-color 0.3s;
    position: relative;
    overflow: hidden;
    isolation: isolate;
    clip-path: polygon(
        6px 0, calc(100% - 6px) 0,
        100% 6px, 100% calc(100% - 6px),
        calc(100% - 6px) 100%, 6px 100%,
        0 calc(100% - 6px), 0 6px
    );
    --wisp-radius: 14px;
    --wisp-ringA: rgba(24,180,255,.8);
    --wisp-ringB: rgba(0,150,255,.85);
    --wisp-glow: 12px;
    display: inline-flex;
    align-items: center;
    line-height: 1;
    height: auto;
    padding: clamp(0.375rem, 1vw, 0.5rem) clamp(0.625rem, 1.5vw, 0.875rem);
    align-self: center;
    min-height: 2.25rem;
    font-size: clamp(0.75rem, 1.4vw, 0.9375rem);
    white-space: nowrap;
}
/* Canvas d'animation */
.nav-button > .nv-wisps{
  position: absolute; inset: 0;
  display: block; pointer-events: none;
  z-index: 0; /* sous ton texte si ton label est z-index:1 */
  mix-blend-mode: lighten; /* optionnel, pour un look plus hextech */
  opacity: 0;
  transition: opacity .25s ease;
}
.nav-button.active > .nv-wisps{
  opacity: 1;
}
/* Actif = plus lumineux + animation ON (le JS détecte .active) */
.nav-button.active::before{ opacity: 1; }
.nav-button:hover::before{ opacity: .9; }

/* Assure que le texte est au-dessus du canvas */
.nav-button > *:not(.nv-wisps){ position: relative; z-index: 1; }
.nav-button::before {
    content: "";
    z-index: 2;
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    pointer-events: none;
    background:
      /* Chanfrein haut-gauche (135deg) */
      linear-gradient(135deg, transparent calc(50% - 1.5px), var(--color-accent) calc(50% - 1.5px), var(--color-accent) calc(50% + 1.5px), transparent calc(50% + 1.5px)) -1px -1px / 8px 8px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 7px 0 / 15% 2px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 0 7px / 2px 15% no-repeat,
      /* Chanfrein haut-droite (45deg) */
      linear-gradient(45deg, transparent calc(50% - 1.5px), var(--color-accent) calc(50% - 1.5px), var(--color-accent) calc(50% + 1.5px), transparent calc(50% + 1.5px)) calc(100% + 1px) -1px / 8px 8px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) calc(100% - 7px) 0 / 15% 2px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 100% 7px / 2px 15% no-repeat,
      /* Chanfrein bas-droite (135deg) */
      linear-gradient(135deg, transparent calc(50% - 1.5px), var(--color-accent) calc(50% - 1.5px), var(--color-accent) calc(50% + 1.5px), transparent calc(50% + 1.5px)) calc(100% + 1px) calc(100% + 1px) / 8px 8px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) calc(100% - 7px) 100% / 15% 2px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 100% calc(100% - 7px) / 2px 15% no-repeat,
      /* Chanfrein bas-gauche (45deg) */
      linear-gradient(45deg, transparent calc(50% - 1.5px), var(--color-accent) calc(50% - 1.5px), var(--color-accent) calc(50% + 1.5px), transparent calc(50% + 1.5px)) -1px calc(100% + 1px) / 8px 8px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 7px 100% / 15% 2px no-repeat,
      linear-gradient(var(--color-accent), var(--color-accent)) 0 calc(100% - 7px) / 2px 15% no-repeat;
}
.nav-button:hover {
    background-color: rgba(255, 255, 255, 0.1);
}
.nav-button.active {
    background-color: #111;
}
.mobile-menu-toggle {
    display: none; /* Géré en responsive */
    background: none;
    border: none;
    color: var(--color-text);
    font-size: 24px;
    cursor: pointer;
    padding: 10px;
}