#nav-active {
  display: none;
}

#nav-active:checked ~ #nav-underlay {
  display: flex;
}

#nav-active:checked ~ .nav {
  box-shadow:
    0 0 0 1px rgba(var(--rgb-black), 0.1),
    0 0 0.1em 0.02em rgba(var(--rgb-black), 0.05)
  ;
}

#nav-active:checked ~ .nav .nav__mobile {
  display: grid;
}

#nav-active:checked ~ .nav .nav__toggle:before {
  transform: rotate(-45deg) translateY(0);
}

#nav-active:checked ~ .nav .nav__toggle:after {
  transform: rotate(45deg) translateY(0);
}



#nav-underlay {
  backdrop-filter: blur(1em);
  -webkit-backdrop-filter: blur(1em);
  background: rgba(var(--rgb-white), 0.5);
  display: none;
  inset: 0;
  position: fixed;
  user-select: none;
  -ms-user-select: none;
  -webkit-user-select: none;
  z-index: 99;
}



.nav {
  backdrop-filter: blur(0.5em);
  -webkit-backdrop-filter: blur(0.5em);
  background: rgba(var(--rgb-white), 0.9);
  position: fixed;
  top: 0;
  user-select: none;
  -ms-user-select: none;
  -webkit-user-select: none;
  width: 100%;
  z-index: 100;
}

.nav__container {
  align-items: center;
  display: flex;
  gap: var(--space-small);
  justify-content: space-between;
  padding: var(--space-small) var(--space-medium);
  width: 100%;
}

.nav__logo {
  align-items: center;
  display: flex;
  flex: 1;
  font-size: var(--font-size-xxxx-small);
  gap: 0.25em;
  letter-spacing: var(--letter-spacing-loose);
  line-height: 1.4em;
}

.nav__logo a {
  color: inherit;
  text-decoration: none;
  text-underline-offset: 0.06em;
}

.nav__logo .icon {
  display: flex;
  gap: 0.2em;
}

.nav__logo .icon svg {
  align-self: center;
  max-height: 100%;
  overflow: visible;
  pointer-events: none;
  width: auto;
}

.nav__logo .icon strong {
  font-weight: 600;
}

.nav__logo .icon--basecamp svg {
  height: 1.35em;
}

.nav__logo .icon--37signals {
  display: none;
}

.nav__logo .icon--37signals svg {
  height: 1.25em;
}

.nav__phrase {
  display: none;
}

.nav__links {
  align-items: center;
  display: none;
  gap: var(--space-small);
}

.nav__links a {
  color: var(--color-black);
  display: flex;
  font-size: var(--font-size-xxxx-small);
  font-weight: inherit;
  letter-spacing: var(--letter-spacing-loose);
  line-height: 2.2em;
  text-decoration: none;
  text-underline-offset: 0.06em;
  white-space: nowrap;
}

.nav__buttons {
  align-items: center;
  display: flex;
  gap: var(--space-small);
}

.nav__button {
  border-radius: 0.25em;
  box-shadow:
    0 0 0 1px rgba(var(--rgb-black), 0.1),
    0 0 0.1em 0.02em rgba(var(--rgb-black), 0.05)
  ;
  color: var(--color-black);
  cursor: pointer;
  display: flex;
  font-size: var(--font-size-xxxx-small);
  font-weight: inherit;
  letter-spacing: var(--letter-spacing-loose);
  line-height: 2.2em;
  padding-left: 0.7625em;
  padding-right: 0.7625em;
  text-decoration: none;
  text-underline-offset: 0.06em;
  white-space: nowrap;
}

.nav__button--signup {
  background: var(--color-green);
  box-shadow: none;
  color: var(--color-white);
  font-weight: 500;
}

.nav__toggle {
  cursor: pointer;
  display: grid;
  font-size: var(--font-size-xxxx-small);
  height: 2.2em;
  margin-right: -0.5em;
  place-items: center;
  position: relative;
  width: 2.2em;
}

.nav__toggle:before,
.nav__toggle:after {
  background: var(--color-black);
  content: '';
  height: 0.125em;
  pointer-events: none;
  position: absolute;
  transition: transform var(--transition);
  width: 1.2em;
  will-change: transform;
}

.nav__toggle:before {
  transform: translateY(-0.225em);
}

.nav__toggle:after {
  transform: translateY(0.225em);
}

.nav__mobile {
  display: none;
  gap: var(--space-large);
  justify-items: center;
  margin: var(--space-x-large) var(--space-medium);
  text-align: center;
}

.nav__mobile a {
  font-size: var(--font-size-medium);
  font-weight: 600;
  letter-spacing: var(--letter-spacing);
  margin-bottom: -0.2875em;
  margin-top: -0.5625em;
}



.nav--stuck {
  box-shadow:
    0 0 0 1px rgba(var(--rgb-black), 0.1),
    0 0 0.1em 0.02em rgba(var(--rgb-black), 0.05)
  ;
  transition: box-shadow var(--transition);
}



@media(hover: hover) {

  .nav__logo a:focus,
  .nav__logo a:hover,
  .nav__links a:focus,
  .nav__links a:hover {
    text-decoration: underline;
  }

  .nav__button {
    transition:
      background var(--transition),
      box-shadow var(--transition)
    ;
  }

  .nav__button:focus,
  .nav__button:hover {
    box-shadow:
      0 0 0 1px rgba(var(--rgb-black), 0.85),
      0 0 0.1em 0.02em rgba(var(--rgb-black), 0.05)
    ;
  }

  .nav__button--signup:focus,
  .nav__button--signup:hover {
    background: var(--color-green-dark);
    box-shadow: none;
    color: var(--color-white);
  }

}



@media(min-width: 64em) {

  #nav-active:checked ~ #nav-underlay,
  #nav-active:checked ~ .nav .nav__mobile,
  #nav-active:checked ~ .nav .nav__toggle {
    display: none;
  }

  #nav-underlay {
    display: none;
  }

  .nav__container {
    padding-left: var(--space-neutral);
    padding-right: var(--space-neutral);
  }

  .nav__links {
    display: flex;
  }

  .nav__toggle,
  .nav__mobile {
    display: none;
  }

}



@media(min-width: 80em) {

  .nav__logo .icon--37signals {
    display: flex;
  }

  .nav__phrase {
    display: initial;
  }

  .nav__phrase--js {
    opacity: 0;
  }

}