/* Application shell: rail (desktop), compact rail (tablet), tab bar (mobile). */

.core-canvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--dur-4) var(--ease-out);
}

:root[data-render="full"][data-core-visible="true"] .core-canvas,
:root[data-render="low"][data-core-visible="true"] .core-canvas,
:root[data-render="static"][data-core-visible="true"] .core-canvas {
  opacity: 1;
}

.app {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  min-height: 100dvh;
}

/* --- rail --------------------------------------------------------------- */
.rail {
  position: sticky;
  top: 0;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: var(--sp-7);
  padding: var(--sp-6) var(--sp-4);
  border-right: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(7, 11, 9, 0.88), rgba(5, 8, 7, 0.94));
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.brand {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  column-gap: var(--sp-3);
  padding: var(--sp-1) var(--sp-2);
  border-radius: var(--r-sm);
}

.brand__mark {
  grid-row: span 2;
  width: 36px;
  height: 36px;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 1.75rem;
  line-height: 1;
  letter-spacing: 0.01em;
}

.brand__descriptor {
  font-size: var(--fs-2xs);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--text-3);
}

.nav ul {
  display: grid;
  gap: 2px;
}

.nav a {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-height: 44px;
  padding: 0 var(--sp-3);
  border-radius: var(--r-sm);
  color: var(--text-2);
  font-weight: 600;
  font-size: var(--fs-md);
  transition:
    color var(--dur-2) var(--ease-out),
    background-color var(--dur-2) var(--ease-out);
}

.nav a:hover {
  color: var(--text-1);
  background: rgba(255, 255, 255, 0.025);
}

.nav a[aria-current="page"] {
  color: var(--text-1);
  background: var(--accent-wash);
}

.nav a[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: -16px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: var(--accent);
  box-shadow: 0 0 12px rgba(61, 220, 151, 0.6);
}

.nav a[aria-current="page"] .icon {
  color: var(--accent);
}

.rail__foot {
  margin-top: auto;
  display: grid;
  gap: var(--sp-2);
  padding: var(--sp-4);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: rgba(255, 255, 255, 0.012);
}

.rail__note {
  font-size: var(--fs-xs);
  line-height: 1.5;
  color: var(--text-3);
}

/* --- main column ---------------------------------------------------------- */
.main-col {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  height: var(--topbar-h);
  padding: 0 var(--gutter);
  border-bottom: 1px solid var(--line);
  background: rgba(4, 6, 5, 0.74);
  backdrop-filter: blur(16px) saturate(1.15);
  -webkit-backdrop-filter: blur(16px) saturate(1.15);
}

.topbar .brand--compact {
  display: none;
}

.topbar__context {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 0;
  font-size: var(--fs-sm);
  color: var(--text-2);
  white-space: nowrap;
}

.topbar__workspace {
  color: var(--text-1);
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topbar__sep {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--text-3);
}

.topbar__right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

.pills {
  display: flex;
  gap: var(--sp-2);
}

.lang {
  position: relative;
  display: flex;
  align-items: center;
}

.lang .icon {
  position: absolute;
  left: 11px;
  color: var(--text-3);
  pointer-events: none;
}

.lang select {
  appearance: none;
  min-height: 36px;
  padding: 0 32px 0 34px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-pill);
  background:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2380918a' stroke-width='2.4' stroke-linecap='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E")
      no-repeat right 12px center,
    var(--surface-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  cursor: pointer;
  transition: border-color var(--dur-2) var(--ease-out);
}

.lang select:hover {
  border-color: var(--line-3);
}

main {
  flex: 1;
  width: 100%;
  max-width: var(--content-max);
  padding: var(--sp-7) var(--gutter) var(--sp-10);
}

.view {
  animation: view-in var(--dur-3) var(--ease-out) both;
}

@keyframes view-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
}

/* --- tab bar (mobile) ------------------------------------------------------- */
.tabbar {
  display: none;
}

/* --- tablet: icon rail -------------------------------------------------------- */
@media (max-width: 1100px) {
  .rail {
    padding: var(--sp-5) var(--sp-3);
    align-items: center;
  }
  .brand {
    grid-template-columns: auto;
    padding: 0;
  }
  .brand__name,
  .brand__descriptor,
  .rail__foot .rail__note,
  .nav a span:not(.icon) {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
  }
  .nav a {
    justify-content: center;
    width: 52px;
    height: 48px;
    padding: 0;
  }
  .nav a[aria-current="page"]::before {
    left: -12px;
  }
  .rail__foot {
    padding: var(--sp-2);
    border: 0;
    background: none;
  }
  .rail__foot .chip {
    writing-mode: vertical-rl;
    transform: rotate(180deg);
  }
}

@media (max-width: 960px) {
  .topbar__workspace,
  .topbar__sep {
    display: none;
  }
  .pill__label {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
  }
  .pill {
    padding: 0 10px;
  }
}

/* --- mobile ---------------------------------------------------------------------- */
@media (max-width: 760px) {
  .app {
    grid-template-columns: minmax(0, 1fr);
  }
  .rail {
    display: none;
  }
  .topbar .brand--compact {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
  }
  .topbar .brand--compact .brand__mark {
    width: 28px;
    height: 28px;
  }
  .topbar .brand--compact .brand__name {
    position: static;
    width: auto;
    height: auto;
    clip: auto;
    font-size: 1.45rem;
  }
  .topbar__context {
    display: none;
  }
  .pills .pill[data-pill="ai"],
  .pills .pill[data-pill="voice"] {
    display: none;
  }
  .lang select {
    padding-right: 26px;
    background-position: right 9px center, 0 0;
  }
  main {
    padding: var(--sp-5) var(--gutter) calc(var(--tabbar-h) + var(--sp-9) + env(safe-area-inset-bottom));
  }
  .tabbar {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 20;
    display: block;
    padding-bottom: env(safe-area-inset-bottom);
    border-top: 1px solid var(--line-2);
    background: rgba(4, 6, 5, 0.9);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
  }
  .tabbar ul {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    height: var(--tabbar-h);
  }
  .tabbar a {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 3px;
    height: 100%;
    font-size: var(--fs-2xs);
    font-weight: 600;
    color: var(--text-3);
    transition: color var(--dur-2) var(--ease-out);
  }
  .tabbar a[aria-current="page"] {
    color: var(--text-1);
  }
  .tabbar a[aria-current="page"] .icon {
    color: var(--accent);
    filter: drop-shadow(0 0 8px rgba(61, 220, 151, 0.55));
  }
}