/* ============================================================
   chat.css · chat shell, backdrops, messages, composer
   ============================================================ */

.chat-view {
  display: flex;
  padding-block: clamp(1rem, 2.5vw, 2rem) clamp(1.5rem, 4vw, 3rem);
}

.chat-shell {
  position: relative;
  display: flex;
  flex-direction: column;
  width: 100%;
  min-height: min(78dvh, 760px);
  max-height: calc(100dvh - var(--header-h) - 4rem);
  overflow: hidden;
  border-radius: var(--r-xl);
  border: 1px solid var(--line);
  background: var(--surface-solid);
  box-shadow: var(--shadow-lg);
  animation: chat-enter 620ms var(--ease-out) both;
  isolation: isolate;
}

/* ---------------- backdrops ---------------- */
.chat-shell::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  transition: opacity 600ms var(--transition), background 600ms var(--transition);
}

.chat-shell[data-background="midnight"]::before {
  background:
    radial-gradient(70% 55% at 50% 0%, color-mix(in oklab, var(--bot-primary, var(--violet)) 24%, transparent), transparent 70%),
    linear-gradient(180deg, transparent, color-mix(in oklab, var(--bot-secondary, var(--teal)) 8%, transparent));
}

.chat-shell[data-background="aurora"]::before {
  background:
    radial-gradient(48% 42% at 12% 8%, color-mix(in oklab, var(--bot-primary, var(--violet)) 42%, transparent), transparent 66%),
    radial-gradient(46% 40% at 92% 22%, color-mix(in oklab, var(--bot-secondary, var(--teal)) 34%, transparent), transparent 64%),
    radial-gradient(56% 44% at 50% 108%, color-mix(in oklab, var(--magenta) 24%, transparent), transparent 68%);
  filter: blur(6px);
  animation: aurora-drift 22s ease-in-out infinite alternate;
}

.chat-shell[data-background="paper"] {
  --paper-tint: color-mix(in oklab, var(--bot-primary, var(--violet)) 6%, var(--surface-solid));
  background: var(--paper-tint);
}
.chat-shell[data-background="paper"]::before {
  background:
    repeating-linear-gradient(180deg, transparent 0 27px, var(--line) 27px 28px);
  opacity: 0.55;
}

.chat-shell[data-background="grid"]::before {
  background:
    linear-gradient(var(--line) 1px, transparent 1px) 0 0 / 34px 34px,
    linear-gradient(90deg, var(--line) 1px, transparent 1px) 0 0 / 34px 34px,
    radial-gradient(60% 50% at 50% 0%, color-mix(in oklab, var(--bot-primary, var(--violet)) 18%, transparent), transparent 72%);
  mask: radial-gradient(120% 100% at 50% 0%, #000 35%, transparent 92%);
  -webkit-mask: radial-gradient(120% 100% at 50% 0%, #000 35%, transparent 92%);
}

/* ---------------- header ---------------- */
.chat-header {
  position: relative;
  z-index: 3;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(0.6rem, 2vw, 1.25rem);
  padding: 0.85rem clamp(0.85rem, 2.2vw, 1.4rem);
  border-bottom: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
}

.back-button {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 0.85rem 0.5rem 0.65rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-soft);
  transition: transform var(--dur) var(--spring), color var(--dur-fast) var(--transition),
    border-color var(--dur-fast) var(--transition), background var(--dur-fast) var(--transition);
}
.back-icon {
  width: 15px;
  height: 15px;
  background: currentColor;
  mask: var(--icon-arrow-left) center / contain no-repeat;
  -webkit-mask: var(--icon-arrow-left) center / contain no-repeat;
  transition: transform var(--dur) var(--spring);
}
.back-button:hover {
  color: var(--text);
  border-color: var(--line-strong);
  background: var(--surface-2);
}
.back-button:hover .back-icon { transform: translateX(-3px); }

.chat-identity { display: flex; align-items: center; gap: 0.75rem; min-width: 0; }
.chat-identity > div { min-width: 0; }
.chat-identity h1 {
  font-size: clamp(0.98rem, 0.9rem + 0.4vw, 1.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.chat-identity p {
  font-size: 0.76rem;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
#chat-avatar {
  background: linear-gradient(145deg, var(--bot-primary, var(--violet)), var(--bot-secondary, var(--teal)));
  box-shadow: 0 12px 30px -14px color-mix(in oklab, var(--bot-primary, var(--violet)) 85%, transparent),
    inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.chat-header-actions { display: flex; align-items: center; gap: 0.4rem; justify-content: flex-end; }

.chat-status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.8rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-soft);
  white-space: nowrap;
}

/* ---------------- backdrop panel ---------------- */
.background-panel {
  position: relative;
  z-index: 3;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.95rem clamp(0.85rem, 2.2vw, 1.4rem);
  border-bottom: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(16px);
  animation: pop-in 300ms var(--ease-out) both;
}
.background-title { font-family: var(--font-display); font-size: 0.92rem; font-weight: 600; }
.background-subtitle { font-size: 0.78rem; color: var(--text-dim); }

.background-options { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.background-option {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.42rem 0.8rem 0.42rem 0.55rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-soft);
  transition: transform var(--dur) var(--spring), color var(--dur-fast) var(--transition),
    border-color var(--dur-fast) var(--transition), background var(--dur-fast) var(--transition);
}
.background-option span {
  width: 16px;
  height: 16px;
  border-radius: 6px;
  border: 1px solid var(--line-strong);
}
.background-option[data-background="midnight"] span { background: linear-gradient(140deg, #10101d, #2a2352); }
.background-option[data-background="aurora"] span { background: linear-gradient(140deg, #7c6cff, #35e0d0 60%, #ee6bff); }
.background-option[data-background="paper"] span { background: linear-gradient(140deg, #f6f3ec, #d9d3c6); }
.background-option[data-background="grid"] span {
  background:
    linear-gradient(#8f8fb0 1px, transparent 1px) 0 0 / 5px 5px,
    linear-gradient(90deg, #8f8fb0 1px, transparent 1px) 0 0 / 5px 5px,
    #14141f;
}
.background-option:hover { transform: translateY(-2px); color: var(--text); border-color: var(--line-strong); }
.background-option.is-active {
  color: var(--text);
  border-color: color-mix(in oklab, var(--bot-primary, var(--violet)) 60%, transparent);
  background: color-mix(in oklab, var(--bot-primary, var(--violet)) 16%, transparent);
}

/* ---------------- messages ---------------- */
.message-list {
  position: relative;
  z-index: 2;
  flex: 1;
  overflow-y: auto;
  overscroll-behavior: contain;
  scroll-behavior: smooth;
  display: flex;
  flex-direction: column;
  gap: 0.95rem;
  padding: clamp(1.1rem, 3vw, 2rem) clamp(0.85rem, 2.6vw, 1.75rem);
}

.welcome-card {
  display: grid;
  justify-items: center;
  gap: 0.75rem;
  margin: auto;
  max-width: 44ch;
  padding: clamp(1.5rem, 4vw, 2.5rem);
  text-align: center;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: var(--surface);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow-md);
  animation: reveal-blur 700ms var(--ease-out) both;
}
.welcome-card .avatar {
  width: 60px;
  height: 60px;
  border-radius: 20px;
  font-size: 1.4rem;
  box-shadow: 0 18px 44px -18px color-mix(in oklab, var(--bot-primary, var(--violet)) 90%, transparent),
    inset 0 0 0 1px rgba(255, 255, 255, 0.2);
  animation: float-y 7s ease-in-out infinite;
}
.welcome-card h2 { font-size: clamp(1.2rem, 1rem + 1vw, 1.6rem); }
.welcome-card p { font-size: 0.9rem; color: var(--text-soft); }

.message-row {
  display: flex;
  align-items: flex-end;
  gap: 0.6rem;
  max-width: min(88%, 62ch);
  animation: message-in 460ms var(--ease-out) both;
}
.message-row.assistant { align-self: flex-start; }
.message-row.user { align-self: flex-end; flex-direction: row-reverse; }

.message-avatar {
  width: 30px;
  height: 30px;
  border-radius: 11px;
  font-size: 0.78rem;
  margin-bottom: 2px;
}

.message-content { display: flex; flex-direction: column; align-items: flex-start; gap: 0.3rem; min-width: 0; }

.message-bubble {
  position: relative;
  padding: 0.78rem 1rem;
  font-size: 0.93rem;
  line-height: 1.68;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--text);
  border-radius: var(--bot-radius, 18px);
  border-end-start-radius: 6px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--dur) var(--transition), box-shadow var(--dur) var(--transition);
}
html[data-theme="dark"] .message-bubble { background: rgba(255, 255, 255, 0.07); backdrop-filter: blur(10px); }
.message-row.assistant:hover .message-bubble { transform: translateY(-1px); box-shadow: var(--shadow-md); }

.message-row.user .message-bubble {
  border: 0;
  color: var(--user-text, #fff);
  background: var(--user-bubble, var(--violet));
  border-radius: var(--bot-radius, 18px);
  border-end-end-radius: 6px;
  box-shadow: 0 14px 34px -18px color-mix(in oklab, var(--bot-primary, var(--violet)) 92%, transparent);
}

.speak-button {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.15rem 0.5rem;
  border-radius: var(--r-pill);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-dim);
  opacity: 0;
  transform: translateY(-3px);
  transition: opacity var(--dur) var(--transition), transform var(--dur) var(--transition),
    color var(--dur-fast) var(--transition), background var(--dur-fast) var(--transition);
}
.message-row:hover .speak-button,
.speak-button:focus-visible { opacity: 1; transform: none; }
.speak-button:hover { color: var(--text); background: var(--surface-2); }

/* typing */
.typing-row {
  display: flex;
  align-items: flex-end;
  gap: 0.6rem;
  align-self: flex-start;
  animation: message-in 320ms var(--ease-out) both;
}
.typing-bubble {
  display: inline-flex;
  align-items: center;
  gap: 0.32rem;
  padding: 0.85rem 1rem;
  border-radius: var(--bot-radius, 18px);
  border-end-start-radius: 6px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  box-shadow: var(--shadow-sm);
}
.typing-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: color-mix(in oklab, var(--bot-primary, var(--violet)) 75%, var(--text));
  animation: dot-pulse 1.25s ease-in-out infinite;
}
.typing-dot:nth-child(2) { animation-delay: 0.14s; }
.typing-dot:nth-child(3) { animation-delay: 0.28s; }

/* error */
.error-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem;
  align-self: center;
  padding: 0.8rem 1rem;
  border-radius: var(--r-md);
  border: 1px solid color-mix(in oklab, #ff5c5c 40%, transparent);
  background: color-mix(in oklab, #ff5c5c 12%, transparent);
  font-size: 0.85rem;
  color: var(--text);
  animation: pop-in 340ms var(--ease-out) both;
}
.error-icon {
  width: 18px;
  height: 18px;
  flex: none;
  background: #ff8080;
  mask: var(--icon-alert) center / contain no-repeat;
  -webkit-mask: var(--icon-alert) center / contain no-repeat;
}
.retry-button {
  padding: 0.35rem 0.85rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line-strong);
  background: var(--surface-2);
  font-size: 0.78rem;
  font-weight: 700;
  transition: transform var(--dur) var(--spring), background var(--dur-fast) var(--transition);
}
.retry-button:hover { transform: translateY(-2px); background: var(--surface); }

/* ---------------- composer ---------------- */
.composer {
  position: relative;
  z-index: 3;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: clamp(0.75rem, 2vw, 1.1rem) clamp(0.85rem, 2.6vw, 1.75rem) clamp(0.9rem, 2.4vw, 1.25rem);
  border-top: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
}

.composer-inner {
  display: flex;
  align-items: flex-end;
  gap: 0.5rem;
  padding: 0.45rem;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: var(--surface-2);
  transition: border-color var(--dur-fast) var(--transition), box-shadow var(--dur) var(--transition);
}
html[data-theme="dark"] .composer-inner { background: rgba(255, 255, 255, 0.05); }
.composer-inner:focus-within {
  border-color: color-mix(in oklab, var(--bot-primary, var(--violet)) 62%, transparent);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--bot-primary, var(--violet)) 16%, transparent);
}

.composer textarea {
  flex: 1;
  min-width: 0;
  max-height: 140px;
  padding: 0.55rem 0.35rem;
  border: 0;
  background: none;
  resize: none;
  outline: none;
  font-size: 0.95rem;
  line-height: 1.6;
}
.composer textarea::placeholder { color: var(--text-dim); }
.composer textarea:disabled { opacity: 0.55; }

.voice-button {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  flex: none;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text-soft);
  transition: transform var(--dur) var(--spring), color var(--dur-fast) var(--transition),
    border-color var(--dur-fast) var(--transition), background var(--dur-fast) var(--transition);
}
.mic-icon {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.voice-button:hover:not(:disabled) { color: var(--text); border-color: var(--line-strong); transform: translateY(-2px); }
.voice-button:disabled { opacity: 0.4; cursor: not-allowed; }
.voice-button.is-listening {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(140deg, #ff5c8a, #ff8a5c);
  animation: listen-ring 1.4s ease-out infinite;
}

.send-button {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  height: 40px;
  padding: 0 1rem;
  flex: none;
  border-radius: var(--r-pill);
  border: var(--send-border, 0);
  color: var(--send-text, #fff);
  background: var(--send-background, var(--violet));
  font-size: 0.85rem;
  font-weight: 700;
  box-shadow: 0 14px 32px -16px color-mix(in oklab, var(--bot-primary, var(--violet)) 90%, transparent);
  transition: transform var(--dur) var(--spring), filter var(--dur-fast) var(--transition),
    opacity var(--dur-fast) var(--transition), box-shadow var(--dur) var(--transition);
}
.send-button:hover:not(:disabled) { transform: translateY(-2px); filter: brightness(1.08) saturate(1.05); }
.send-button:active:not(:disabled) { transform: scale(0.96); }
.send-button:disabled { opacity: 0.55; cursor: progress; box-shadow: none; }
.send-icon {
  width: 16px;
  height: 16px;
  background: currentColor;
  mask: var(--icon-send) center / contain no-repeat;
  -webkit-mask: var(--icon-send) center / contain no-repeat;
  transition: transform var(--dur) var(--spring);
}
.send-button:hover:not(:disabled) .send-icon { transform: translate(2px, -2px); }

.composer-hint {
  font-size: 0.74rem;
  color: var(--text-dim);
  text-align: center;
  min-height: 1.2em;
}

/* ---------------- responsive ---------------- */
@media (max-width: 900px) {
  .chat-shell { max-height: none; min-height: calc(100dvh - var(--header-h) - 5rem); border-radius: var(--r-lg); }
  .chat-header { grid-template-columns: auto minmax(0, 1fr); grid-template-areas: "back identity" "actions actions"; }
  .back-button { grid-area: back; }
  .chat-identity { grid-area: identity; }
  .chat-header-actions {
    grid-area: actions;
    justify-content: flex-start;
    flex-wrap: wrap;
    padding-top: 0.3rem;
  }
}

@media (max-width: 620px) {
  .chat-view { padding-inline: 0; margin-inline: calc(var(--gutter) * -0.5); }
  .message-row { max-width: 92%; }
  .chat-status { display: none; }
  .send-label { display: none; }
  .send-button { width: 40px; padding: 0; justify-content: center; }
  .speak-button { opacity: 1; transform: none; }
  .background-panel { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 420px) {
  .tool-button span { display: none; }
  .tool-button { width: 38px; height: 38px; justify-content: center; padding: 0; }
}