/* =============================================================================
   15. SITE — AI ASSISTANT
   Floating chat launcher, fixed bottom-right. CSS-only checkbox toggle —
   no JavaScript. The panel's input/send button are real disabled controls,
   not fake non-semantic placeholders.
   ============================================================================= */
/* Fixed floating chat widget, CSS-only checkbox toggle. Depends on: tokens.css, base/motion.css (glow-pulse keyframe). */
.ai-assistant {
  display: none !important;
  position: fixed;
  right: var(--space-6);
  bottom: var(--space-6);
  z-index: var(--z-assistant);
}

/* Ambient halo behind the button, declared before it in the markup so it
   paints underneath without needing a negative z-index inside this fixed
   stacking context. */
.ai-assistant__glow {
  position: absolute;
  right: -30px;
  bottom: -30px;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--color-accent-soft) 0%, transparent 72%);
  filter: blur(10px);
  pointer-events: none;
  animation: glow-pulse 4.5s ease-in-out infinite;
}

.ai-assistant__toggle-input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.ai-assistant__button {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  height: 56px;
  padding: 0 1.1rem 0 0.9rem;
  border-radius: var(--radius-pill);
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-strong) 100%);
  border: 1px solid color-mix(in oklch, var(--color-accent), white 18%);
  box-shadow: 0 12px 28px color-mix(in oklch, var(--color-accent), transparent 62%), 0 1px 0 oklch(100% 0 0 / 0.3) inset;
  background-size: 150% 150%;
  cursor: pointer;
  transition: transform var(--transition-slow), box-shadow var(--transition-slow), filter var(--transition-slow);
}

.ai-assistant__button:hover {
  transform: translateY(-3px) scale(1.015);
  background-position: 100% 50%;
  box-shadow: 0 18px 36px color-mix(in oklch, var(--color-accent), transparent 48%), 0 1px 0 oklch(100% 0 0 / 0.36) inset;
  filter: brightness(1.06);
}

.ai-assistant__toggle-input:focus-visible ~ .ai-assistant__button {
  outline: 2px solid var(--color-accent-strong);
  outline-offset: 3px;
}

.ai-assistant__button-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.ai-assistant__button-icon svg {
  transition: transform var(--transition-slow);
}

.ai-assistant__button:hover .ai-assistant__button-icon svg {
  transform: rotate(-8deg) scale(1.06);
}

.ai-assistant__button-label {
  font-family: var(--font-heading);
  font-weight: var(--fw-semibold);
  font-size: var(--text-sm);
  color: var(--color-text-on-accent);
  white-space: nowrap;
}

.ai-assistant__button-dot {
  position: absolute;
  top: 2px;
  right: 2px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-highlight);
  border: 2px solid var(--color-surface);
  animation: glow-pulse 2.4s ease-in-out infinite;
}

@media (max-width: 480px) {
  .ai-assistant__button-label {
    display: none;
  }

  .ai-assistant__button {
    padding: 0;
    width: 56px;
    justify-content: center;
  }
}

.ai-assistant__panel {
  position: absolute;
  right: 0;
  bottom: calc(56px + var(--space-4));
  width: min(360px, calc(100vw - 2 * var(--space-6)));
  max-height: min(480px, calc(100vh - 140px));
  display: flex;
  flex-direction: column;
  background: var(--color-glass-strong);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-panel-hover);
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px) scale(0.98);
  transform-origin: bottom right;
  pointer-events: none;
  transition: opacity var(--transition-panel), transform var(--transition-panel), visibility var(--transition-panel);
}

/* Brand stripe across the top edge — a small premium touch that also
   signals which app this panel belongs to at a glance. */
.ai-assistant__panel::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-strong));
}

.ai-assistant__toggle-input:checked ~ .ai-assistant__panel {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.ai-assistant__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  flex-shrink: 0;
}

.ai-assistant__header-identity {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.ai-assistant__avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-soft-surface);
  border: 1px solid var(--color-accent-border);
  box-shadow: 0 0 0 3px var(--color-soft-surface);
  flex-shrink: 0;
}

.ai-assistant__header-text {
  display: flex;
  flex-direction: column;
  line-height: var(--lh-logo);
}

.ai-assistant__title {
  font-family: var(--font-heading);
  font-weight: var(--fw-semibold);
  font-size: var(--text-sm);
  color: var(--color-text-primary);
}

.ai-assistant__status {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-family: var(--font-mono);
  font-size: var(--text-label-xs);
  color: var(--color-text-tertiary);
}

.ai-assistant__status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-highlight);
  animation: glow-pulse 2.4s ease-in-out infinite;
}

.ai-assistant__close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  color: var(--color-text-tertiary);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  flex-shrink: 0;
  transition: background var(--transition-base), color var(--transition-base), transform var(--transition-base);
}

.ai-assistant__close:hover {
  background: var(--color-border);
  color: var(--color-text-primary);
  transform: rotate(8deg) scale(1.06);
}

.ai-assistant__body {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-5);
  overflow-y: auto;
}

.ai-assistant__message {
  display: flex;
  align-items: flex-end;
  gap: var(--space-2);
}

.ai-assistant__message-avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--color-soft-surface);
  flex-shrink: 0;
}

.ai-assistant__message-bubble {
  max-width: 80%;
  background: var(--color-soft-surface);
  color: var(--color-text-primary);
  font-size: var(--text-xs);
  line-height: var(--lh-body-sm);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  border-bottom-left-radius: var(--radius-sm);
}

.ai-assistant__footer {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-5);
  border-top: 1px solid var(--color-border);
  flex-shrink: 0;
}

.ai-assistant__input {
  flex: 1;
  min-width: 0;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--color-text-primary);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: 0.6rem var(--space-4);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.ai-assistant__input::placeholder {
  color: var(--color-text-tertiary);
}

.ai-assistant__input:focus-visible {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-soft-surface);
}

.ai-assistant__input:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.ai-assistant__send {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent-strong), var(--color-accent), var(--color-glow-strong));
  background-size: 150% 150%;
  flex-shrink: 0;
  transition: background-position var(--transition-slow), transform var(--transition-slow), box-shadow var(--transition-slow);
}

.ai-assistant__send:not(:disabled):hover {
  background-position: 100% 50%;
  transform: translateY(-2px);
  box-shadow: 0 10px 20px color-mix(in oklch, var(--color-accent), transparent 58%);
}

.ai-assistant__send:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

:root[data-theme="dark"] .ai-assistant__button {
  color: var(--color-text-on-accent);
  background: linear-gradient(135deg, oklch(57% 0.2 278), oklch(64% 0.2 278) 55%, oklch(67% 0.17 215));
  border-color: color-mix(in oklch, var(--color-glow), white 14%);
  box-shadow: 0 12px 28px oklch(56% 0.19 278 / 0.3), 0 0 20px oklch(68% 0.18 215 / 0.1),
    0 1px 0 oklch(100% 0 0 / 0.3) inset;
}

:root[data-theme="dark"] .ai-assistant__button:hover {
  box-shadow: 0 18px 36px oklch(56% 0.19 278 / 0.38), 0 0 26px oklch(68% 0.18 215 / 0.16),
    0 1px 0 oklch(100% 0 0 / 0.36) inset;
}

:root[data-theme="dark"] .ai-assistant__toggle-input:focus-visible ~ .ai-assistant__button,
:root[data-theme="dark"] .ai-assistant__close:focus-visible {
  outline-color: var(--color-glow);
}

:root[data-theme="dark"] .ai-assistant__close:hover {
  background: oklch(100% 0 0 / 0.09);
  color: var(--color-text-primary);
}

:root[data-theme="dark"] .ai-assistant__send:not(:disabled) {
  background: linear-gradient(135deg, var(--color-accent-strong), var(--color-accent), var(--color-glow));
  box-shadow: 0 8px 18px oklch(56% 0.19 278 / 0.24);
}

:root[data-theme="dark"] .ai-assistant__send:not(:disabled):focus-visible {
  outline: 2px solid var(--color-glow);
  outline-offset: 3px;
}

:root[data-theme="dark"] .ai-assistant__send:disabled {
  background: oklch(25% 0.026 264 / 0.76);
  color: var(--color-text-tertiary);
  border: 1px solid var(--color-border);
  box-shadow: none;
  opacity: 0.72;
}

:root[data-theme="dark"] .ai-assistant__input {
  color: var(--color-text-primary);
  background: var(--color-bg-input);
  border-color: color-mix(in oklch, var(--color-glow), transparent 70%);
  box-shadow: 0 1px 0 oklch(100% 0 0 / 0.05) inset;
}

:root[data-theme="dark"] .ai-assistant__input::placeholder {
  color: var(--color-text-tertiary);
}

:root[data-theme="dark"] .ai-assistant__input:focus-visible {
  border-color: var(--color-glow);
  box-shadow: 0 0 0 3px oklch(68% 0.18 215 / 0.14);
}

:root[data-theme="dark"] .ai-assistant__input:disabled {
  color: var(--color-text-secondary);
  background: oklch(16% 0.027 264 / 0.86);
  border-color: color-mix(in oklch, var(--color-border), transparent 14%);
  opacity: 0.82;
}

@media (max-width: 480px) {
  .ai-assistant {
    right: var(--space-4);
    bottom: var(--space-4);
  }
}