/* ==========================================================================
   LUMEN DENTAL — components
   buttons · header · mobile menu · sticky booking bar
   ========================================================================== */

.btn {
  --bg: var(--char); --fg: var(--warm); --bg-h: var(--sage-dk);
  display: inline-flex; align-items: center; justify-content: center; gap: 0.7em;
  min-height: 54px; padding: 0.85em 1.7em;
  background: var(--bg); color: var(--fg);
  border: 1.5px solid var(--bg); border-radius: 999px;
  font-size: 0.98rem; font-weight: 600; line-height: 1.1; white-space: nowrap;
  transition: background-color 0.3s var(--ease), border-color 0.3s var(--ease), color 0.3s var(--ease);
}
.btn:hover, .btn:focus-visible { background: var(--bg-h); border-color: var(--bg-h); }
.btn .i { transition: transform 0.35s var(--ease); }
.btn:hover .i, .btn:focus-visible .i { transform: translateX(4px); }

.btn--sage { --bg: var(--sage-dk); --bg-h: var(--char); }
.btn--light { --bg: var(--warm); --fg: var(--char); --bg-h: var(--sage-lt); }
.btn--light:hover, .btn--light:focus-visible { color: var(--char); }
.btn--ghost { --bg: transparent; --fg: var(--char); border-color: var(--line-strong); }
.btn--ghost:hover, .btn--ghost:focus-visible { background: var(--beige); border-color: var(--char); color: var(--char); }
.dark .btn--ghost { --fg: var(--warm); border-color: var(--line-inv); }
.dark .btn--ghost:hover { background: rgba(255,255,255,0.08); border-color: var(--warm); color: var(--warm); }
.btn--sm { min-height: 44px; padding: 0.6em 1.3em; font-size: 0.92rem; }
.btn--lg { min-height: 62px; padding-inline: 2.2em; font-size: 1.05rem; }
.btn--block { width: 100%; }

.link {
  display: inline-flex; align-items: center; gap: 0.5em; min-height: 44px;
  font-weight: 600; color: var(--sage-dk);
  background: linear-gradient(currentColor, currentColor) left calc(100% - 9px) / 100% 1.5px no-repeat;
  transition: background-size 0.4s var(--ease), color 0.3s;
}
.link .i { width: 1em; height: 1em; transition: transform 0.3s var(--ease); }
.link:hover .i, .link:focus-visible .i { transform: translateX(4px); }
.link:hover { background-size: 40% 1.5px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 60;
  background: rgba(252, 250, 245, 0.94);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.site-header.is-scrolled { border-bottom-color: var(--line); box-shadow: 0 8px 28px rgba(36, 36, 31, 0.05); }

.site-header__inner {
  position: relative; z-index: 2; background: transparent;
  display: flex; align-items: center; justify-content: space-between; gap: 2rem;
  min-height: var(--header-h);
}

.logo { display: inline-flex; align-items: center; gap: 0.7rem; line-height: 1; }
.logo__mark { width: 34px; height: 34px; flex: none; }
.logo__text { display: grid; gap: 0.3em; }
.logo__name { font-family: var(--serif); font-size: 1.5rem; font-weight: 400; letter-spacing: 0.14em; text-transform: uppercase; }
.logo__sub { font-size: 0.6rem; font-weight: 600; letter-spacing: 0.5em; text-transform: uppercase; color: var(--sage-dk); }

.nav { display: none; }
.nav__list { display: flex; align-items: center; gap: clamp(1.4rem, 2.6vw, 2.6rem); }
.nav__link { position: relative; display: inline-block; padding-block: 0.6em; font-size: 0.98rem; font-weight: 500; color: var(--char-2); transition: color 0.25s; }
.nav__link::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0.15em; height: 1.5px; background: var(--sage-dk); transform: scaleX(0); transform-origin: left; transition: transform 0.4s var(--ease); }
.nav__link:hover, .nav__link.is-active { color: var(--char); }
.nav__link:hover::after, .nav__link.is-active::after { transform: scaleX(1); }

.header__cta { display: none; }

.menu-toggle { width: 46px; height: 46px; margin-right: -8px; display: grid; place-items: center; }
.menu-toggle__bars { position: relative; width: 24px; height: 12px; }
.menu-toggle__bars::before, .menu-toggle__bars::after {
  content: ""; position: absolute; left: 0; right: 0; height: 1.6px; background: var(--char);
  transition: transform 0.4s var(--ease), top 0.4s var(--ease);
}
.menu-toggle__bars::before { top: 0; }
.menu-toggle__bars::after { top: 10px; }
.menu-open .menu-toggle__bars::before { top: 5px; transform: rotate(45deg); }
.menu-open .menu-toggle__bars::after { top: 5px; transform: rotate(-45deg); }

.mobile-menu {
  position: fixed; inset: 0; z-index: 1;
  display: flex; flex-direction: column;
  padding: calc(var(--header-h) + 24px) var(--gutter) calc(96px + env(safe-area-inset-bottom));
  background: var(--warm); overflow-y: auto;
  visibility: hidden; opacity: 0;
  transition: opacity 0.35s var(--ease), visibility 0s linear 0.35s;
}
.menu-open .mobile-menu { visibility: visible; opacity: 1; transition: opacity 0.35s var(--ease), visibility 0s; }
.mobile-menu__list { display: grid; margin-block: auto; }
.mobile-menu__link {
  display: flex; align-items: baseline; gap: 1rem; padding-block: 0.28em;
  border-bottom: 1px solid var(--line);
  font-family: var(--serif); font-weight: 300; font-size: clamp(2.2rem, 10vw, 3.2rem); line-height: 1.15; letter-spacing: -0.02em;
  opacity: 0; transform: translateY(14px);
  transition: opacity 0.3s, transform 0.3s, color 0.25s;
}
.mobile-menu__link span { font-family: var(--sans); font-size: 0.7rem; font-weight: 600; letter-spacing: 0.16em; color: var(--sage-dk); }
.mobile-menu__link:hover { color: var(--sage-dk); font-style: italic; }
.menu-open .mobile-menu__link { opacity: 1; transform: none; transition: opacity 0.7s var(--ease), transform 0.7s var(--ease), color 0.25s; transition-delay: calc(0.12s + var(--i) * 55ms); }
.mobile-menu__foot { display: grid; gap: 1rem; margin-top: 1.8rem; color: var(--ink-2); font-size: 0.95rem; }
.mobile-menu__meta { display: flex; flex-wrap: wrap; gap: 0.3rem 1.6rem; }

.book-bar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 55;
  display: grid; grid-template-columns: 1fr auto; gap: 10px;
  padding: 10px var(--gutter) calc(10px + env(safe-area-inset-bottom));
  background: rgba(252, 250, 245, 0.97); border-top: 1px solid var(--line);
  transform: translateY(101%); transition: transform 0.5s var(--ease);
}
.book-bar.is-visible { transform: none; }
.book-bar .btn { min-height: 52px; }
.book-bar__call { width: 52px; padding: 0; }
.menu-open .book-bar { transform: none; z-index: 65; }

@media (min-width: 1000px) {
  .nav { display: block; }
  .header__cta { display: inline-flex; }
  .menu-toggle, .mobile-menu, .book-bar { display: none; }
}