:root {
  --header-height: 4.75rem;
  --header-shell-padding: 0.8rem;
}

.header {
  position: sticky;
  top: 0.75rem;
  z-index: 50;
  width: min(100% - 1.25rem, 1200px);
  margin: 0 auto;
  padding: 0;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  min-height: var(--header-height);
  padding: 0.7rem 1rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 1.7rem;
  background: rgba(13, 17, 22, 0.7);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.18);
  transition: background-color 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.header--scrolled .nav {
  background: rgba(13, 17, 22, 0.88);
  border-color: rgba(255, 255, 255, 0.12);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.22);
}

body.light-mode .nav {
  background: rgba(255, 255, 255, 0.78);
  border-color: rgba(15, 23, 42, 0.08);
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
}

body.light-mode .header--scrolled .nav {
  background: rgba(255, 255, 255, 0.92);
}

.nav__brand {
  font-size: 1rem;
  color: var(--heading);
  font-weight: 700;
  letter-spacing: -0.04em;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.5rem 0.85rem;
  background: rgba(255, 255, 255, 0.02);
}

.nav__menu {
  display: none;
}

.header__bar {
  position: relative;
  z-index: 10;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.28rem;
  width: 3rem;
  height: 3rem;
  padding: 0.7rem;
  border-radius: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(15, 23, 42, 0.72);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 8px 22px rgba(0, 0, 0, 0.16);
}

.header__bar span {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 999px;
  background: var(--heading);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

body.light-mode .header__bar {
  background: rgba(255, 255, 255, 0.85);
  border-color: rgba(15, 23, 42, 0.08);
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
}

@media (min-width: 768px) {
  :root {
    --header-height: 5.5rem;
  }

  .header {
    top: 1rem;
    width: min(100% - 2rem, 1200px);
  }

  .nav {
    padding: 0.9rem 1.2rem;
    border-radius: 2rem;
  }

  .nav__brand {
    font-size: 1.05rem;
  }

  .nav__menu {
    display: flex;
    align-items: center;
    gap: 1.4rem;
  }

  .header__link {
    font-size: var(--size-sm);
    color: var(--muted);
    transition: color 0.2s ease;
    font-weight: 600;
  }

  .header__link:hover,
  .header__link:focus-visible {
    color: var(--heading);
  }

  .header__line {
    width: 1px;
    height: 1.8rem;
    background: var(--line);
  }

  .header__sun {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(148, 163, 184, 0.05);
    color: var(--muted);
  }

  .header__sun svg {
    width: 1.2rem;
    height: 1.2rem;
  }

  .header__resume {
    font-size: var(--size-sm);
    padding-block: 0.7rem;
  }

  .header__bar {
    display: none;
  }
}