:root {
  --radius-pill: 999px;
}

html,
body {
  overflow-x: clip;
}

body.menu-open {
  overflow: hidden;
}

.topbar,
.main-nav {
  display: flex;
  align-items: center;
}

.topbar {
  position: relative;
  justify-content: space-between;
  gap: 16px;
  padding: 4px 0 28px;
}

.brand {
  font-size: 18px;
  font-weight: 500;
  letter-spacing: -0.05em;
}

.main-nav {
  gap: 10px;
}

.menu-toggle,
.menu-overlay {
  display: none;
}

.menu-toggle {
  position: relative;
  z-index: 30;
  width: 52px;
  height: 52px;
  padding: 0;
  border: 1px solid rgba(17, 17, 17, 0.08);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow:
    0 20px 30px rgba(17, 17, 17, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.65);
  cursor: pointer;
  backdrop-filter: blur(16px);
}

.menu-toggle span {
  position: absolute;
  left: 14px;
  width: 24px;
  height: 2px;
  border-radius: 999px;
  background: #111111;
  transition:
    transform 220ms ease,
    opacity 180ms ease,
    top 220ms ease;
}

.menu-toggle span:nth-child(1) {
  top: 18px;
}

.menu-toggle span:nth-child(2) {
  top: 25px;
}

.menu-toggle span:nth-child(3) {
  top: 32px;
}

.menu-panel {
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-link {
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  background: transparent;
  color: #3a3a3a;
  padding: 7px 12px;
  font-size: 0.82rem;
  line-height: 1;
  transition:
    background-color 160ms ease,
    border-color 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.nav-link.is-active,
.nav-link:hover {
  background: var(--surface-soft, #f7f7f7);
  border-color: var(--line, #ececec);
  color: var(--text, #111111);
}

.chat-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-direction: row;
  gap: 6px;
  padding: 12px 18px;
  border: none;
  border-radius: 10px;
  background: #000000;
  color: #ffffff;
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 500;
  line-height: 1;
  outline: none;
  text-decoration: none;
  box-shadow:
    0 40px 24px rgba(0, 0, 0, 0.06),
    0 23px 14px rgba(0, 0, 0, 0.08),
    0 10px 10px rgba(0, 0, 0, 0.12),
    0 3px 6px rgba(0, 0, 0, 0.19);
}

@media (min-width: 961px) {
  .topbar {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    min-height: 56px;
  }

  .brand {
    position: static;
    justify-self: start;
  }

  .menu-panel {
    display: contents;
  }

  .main-nav {
    grid-column: 2;
    justify-content: center;
  }

  .chat-link {
    grid-column: 3;
    justify-self: end;
  }
}

@media (max-width: 960px) {
  .topbar {
    padding-bottom: 22px;
  }

  .menu-toggle,
  .menu-overlay {
    display: block;
  }

  .menu-toggle {
    margin-left: auto;
  }

  .menu-overlay {
    position: fixed;
    inset: 0;
    z-index: 20;
    background: rgba(17, 17, 17, 0.28);
    opacity: 0;
    pointer-events: none;
    transition: opacity 220ms ease;
  }

  .menu-panel {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 25;
    width: min(86vw, 380px);
    padding: 104px 24px 28px;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 22px;
    background: var(--surface, var(--bg, #ffffff));
    border-left: 1px solid rgba(17, 17, 17, 0.08);
    box-shadow: none;
    transform: translateX(100%);
    transition: transform 260ms cubic-bezier(0.22, 1, 0.36, 1);
  }

  .topbar.menu-open .menu-overlay {
    opacity: 1;
    pointer-events: auto;
  }

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

  .topbar.menu-open .menu-toggle span:nth-child(1) {
    top: 25px;
    transform: rotate(45deg);
  }

  .topbar.menu-open .menu-toggle span:nth-child(2) {
    opacity: 0;
  }

  .topbar.menu-open .menu-toggle span:nth-child(3) {
    top: 25px;
    transform: rotate(-45deg);
  }

  .main-nav {
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }

  .menu-panel .nav-link {
    display: flex;
    align-items: center;
    min-height: 56px;
    padding: 10px 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    color: var(--text, #111111);
    font-size: 1rem;
    font-weight: 500;
  }

  .menu-panel .nav-link.is-active,
  .menu-panel .nav-link:hover {
    background: transparent;
    border-color: transparent;
    color: var(--text, #111111);
  }

  .chat-link {
    min-height: 56px;
    border-radius: 18px;
    box-shadow:
      0 30px 40px rgba(0, 0, 0, 0.08),
      0 10px 20px rgba(0, 0, 0, 0.12);
  }
}

@media (max-width: 640px) {
  .brand {
    font-size: 1.2rem;
  }

  .menu-panel {
    width: 100vw;
    padding: 92px 20px 24px;
  }
}