/* ============================================================
 * landing.css — Landing view (ChatGPT Aesthetic + Hero + Cards + Top Nav)
 *
 * - Top navigation bar (6 items, version pill, brand)
 * - Hero heading "~ oh-my-lama"
 * - Centered prompt input capsule (textarea inside form / composer box)
 * - Five feature cards (62 models / Pictures / Tools / KB / Integrations)
 * - Card grid: 1 col (mobile ≤480) / 2 cols (481–1024) / 5 cols (>1024)
 *
 * Uses only variables defined in tokens.css.
 * Validates: Requirements 1.1, 1.2, 1.9, 12.4–12.6, 13.6
 * ============================================================ */

/* ─── Root Container ──────────────────────────────────────────────── */
.landing {
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 100dvh;
  width: 100%;
  box-sizing: border-box;
  background: var(--bg-0);
  color: var(--text-1);
  overflow-y: auto;
  overflow-x: hidden;
  position: relative;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.landing[hidden] {
  display: none !important;
}

/* ─── Header / Top Nav (ChatGPT Minimal Style) ────────────────────── */
.landing__header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-6);
  background: var(--bg-0);
  border-bottom: 1px solid var(--border-subtle);
  box-sizing: border-box;
  backdrop-filter: blur(8px);
}

.landing__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  color: var(--text-1);
  user-select: none;
  flex-shrink: 0;
}

.landing__brand-mark,
.landing__brand-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-md);
  color: var(--brand-1);
}

.landing__brand-name {
  font-size: var(--font-size-base);
  letter-spacing: -0.02em;
  font-weight: 600;
}

.landing__nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  min-width: 0;
}

.landing__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  margin: 0;
  padding: 0;
}

.landing__nav-item {
  display: inline-flex;
  align-items: center;
}

.landing__nav-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--text-2);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
  white-space: nowrap;
}

.landing__nav-link:hover {
  background: var(--bg-1);
  color: var(--text-1);
}

/* Accessible focus ring (Req 13.6) */
.landing__nav-link:focus-visible {
  outline: 2px solid var(--brand-1);
  outline-offset: 1px;
}

.landing__nav-link--stub {
  color: var(--text-3);
}

.landing__nav-tag {
  font-size: 10px;
  padding: 1px var(--space-2);
  border-radius: var(--radius-pill);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
  line-height: 1.2;
}

.landing__nav-tag--new {
  background: var(--brand-1);
  color: var(--text-on-accent);
}

.landing__nav-tag--beta {
  background: var(--info);
  color: var(--text-on-accent);
}

.landing__header-right {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.landing__version {
  padding: 2px var(--space-2);
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-size: var(--font-size-xs);
  color: var(--text-3);
  font-family: var(--font-mono);
  white-space: nowrap;
  user-select: none;
}

/* ─── Main Hero & Center Wrapper ──────────────────────────────────── */
.landing__main {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-8) var(--space-6) var(--space-12);
  box-sizing: border-box;
}

.landing__center-wrapper {
  width: 100%;
  max-width: 820px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-8);
  margin: auto 0;
}

.landing__heading {
  font-size: clamp(26px, 4.5vw, 36px);
  font-weight: 600;
  letter-spacing: -0.03em;
  margin: 0;
  text-align: center;
  color: var(--text-1);
  background: var(--brand-grad);
  -webkit-background-clip: text;
          background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ─── Composer Form (ChatGPT Floating Capsule) ────────────────────── */
.landing__input-form {
  position: relative;
  width: 100%;
  max-width: 768px;
  box-sizing: border-box;
}

.landing__composer-box {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4) var(--space-3) var(--space-4);
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2);
  box-sizing: border-box;
  transition: border-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}

.landing__composer-box:focus-within {
  border-color: var(--brand-1);
  box-shadow: var(--shadow-glow);
}

/* Fallback for legacy layout structure */
.landing__input-form:not(:has(.landing__composer-box)) {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-2);
}

.landing__input {
  width: 100%;
  flex: 1 1 auto;
  background: transparent;
  border: 0;
  outline: none;
  color: var(--text-1);
  font-size: var(--font-size-base);
  line-height: 1.5;
  font-family: inherit;
  resize: none;
  min-height: 24px;
  max-height: 200px;
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  scrollbar-width: thin;
}

.landing__input::placeholder {
  color: var(--text-3);
}

.landing__composer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-top: var(--space-1);
}

.landing__composer-hint {
  font-size: var(--font-size-xs);
  color: var(--text-3);
  user-select: none;
}

.landing__input-submit {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-pill);
  background: var(--bg-2);
  color: var(--text-3);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  cursor: not-allowed;
  transition: all var(--dur) var(--ease);
  padding: 0;
}

/* Active submit button state (when text is present) */
.landing__input-submit--active,
.landing__input-submit:not([disabled]) {
  background: var(--brand-grad);
  color: var(--text-on-accent);
  border-color: transparent;
  cursor: pointer;
}

.landing__input-submit--active:hover,
.landing__input-submit:not([disabled]):hover {
  transform: scale(1.05);
  filter: brightness(1.1);
  box-shadow: var(--shadow-1);
}

/* Accessible focus ring (Req 13.6) */
.landing__input-submit:focus-visible {
  outline: 2px solid var(--brand-1);
  outline-offset: 2px;
}

/* ─── Cards Grid (Req 1.1) ────────────────────────────────────────── */
.landing__cards {
  width: 100%;
  display: grid;
  gap: var(--space-3);
  /* Desktop (>1024px) default: 5 columns (Req 12.6) */
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.landing__card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--bg-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: var(--text-1);
  text-align: left;
  cursor: pointer;
  box-sizing: border-box;
  transition: transform var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}

.landing__card:hover {
  transform: translateY(-2px);
  border-color: var(--brand-1);
  background: var(--bg-2);
  box-shadow: var(--shadow-1);
}

/* Accessible focus ring (Req 13.6) */
.landing__card:focus-visible {
  outline: 2px solid var(--brand-1);
  outline-offset: 2px;
  border-color: var(--brand-1);
}

.landing__card-icon-wrapper,
.landing__card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-2);
  font-size: 24px;
  line-height: 1;
  transition: color var(--dur) var(--ease);
}

.landing__card:hover .landing__card-icon-wrapper,
.landing__card:hover .landing__card-icon {
  color: var(--brand-1);
}

.landing__card-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
  width: 100%;
}

.landing__card-label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--text-1);
  line-height: 1.3;
}

.landing__card-desc {
  font-size: var(--font-size-xs);
  color: var(--text-3);
  line-height: 1.3;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

/* ─── Tablet (481–1024px): 2 columns (Req 12.5) ───────────────────── */
@media (max-width: 1024px) {
  .landing__cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .landing__main {
    padding: var(--space-6) var(--space-4) var(--space-8);
  }

  .landing__center-wrapper {
    gap: var(--space-6);
  }
}

/* ─── Mobile (≤480px): 1 column (Req 12.4) ────────────────────────── */
@media (max-width: 480px) {
  .landing__header {
    padding: var(--space-2) var(--space-3);
    gap: var(--space-2);
    flex-wrap: wrap;
  }

  .landing__nav {
    order: 3;
    flex-basis: 100%;
    justify-content: flex-start;
  }

  .landing__nav-list {
    overflow-x: auto;
    flex-wrap: nowrap;
    width: 100%;
    padding-bottom: 2px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .landing__nav-list::-webkit-scrollbar {
    display: none;
  }

  .landing__nav-link {
    flex: 0 0 auto;
    white-space: nowrap;
    padding: var(--space-1) var(--space-2);
  }

  .landing__version {
    margin-left: auto;
  }

  .landing__main {
    padding: var(--space-4) var(--space-3) var(--space-6);
  }

  .landing__center-wrapper {
    gap: var(--space-5);
  }

  .landing__heading {
    font-size: 24px;
  }

  .landing__composer-hint {
    display: none;
  }

  .landing__cards {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  .landing__card {
    flex-direction: row;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
  }

  .landing__card-desc {
    -webkit-line-clamp: 1;
  }
}