:root {
  --bg: #060a13;
  --panel: rgba(15, 23, 42, 0.72);
  --panel-strong: rgba(15, 23, 42, 0.9);
  --panel-soft: rgba(148, 163, 184, 0.06);
  --border: rgba(148, 163, 184, 0.16);
  --border-strong: rgba(148, 163, 184, 0.28);
  --text: #e8eefb;
  --muted: #94a3b8;
  --muted-2: #64748b;
  --accent: #38bdf8;
  --accent-2: #818cf8;
  --accent-3: #22d3ee;
  --accent-ink: #03111f;
  --avatar-ink: #03111f;
  --danger: #fb7185;
  --success: #34d399;
  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --shadow: 0 24px 70px rgba(2, 6, 23, 0.55);
  --font-sans: "Inter", "SF Pro Text", -apple-system, BlinkMacSystemFont,
    "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", "Cascadia Code", Consolas,
    monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  position: relative;
  isolation: isolate;
  margin: 0;
  min-height: 100dvh;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(58rem 38rem at 12% -12%, rgba(56, 189, 248, 0.16), transparent 62%),
    radial-gradient(48rem 34rem at 98% 8%, rgba(129, 140, 248, 0.15), transparent 60%),
    radial-gradient(44rem 30rem at 52% 112%, rgba(34, 211, 238, 0.09), transparent 62%);
  pointer-events: none;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(148, 163, 184, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(70% 60% at 50% 0%, #000 20%, transparent 100%);
  -webkit-mask-image: radial-gradient(70% 60% at 50% 0%, #000 20%, transparent 100%);
  pointer-events: none;
}

::selection {
  background: rgba(56, 189, 248, 0.28);
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.app {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: min(1000px, 100%);
  height: 100dvh;
  margin: 0 auto;
  padding: clamp(12px, 2.4vw, 22px) clamp(12px, 3vw, 28px)
    clamp(10px, 2vw, 18px);
}

/* ---------- 顶栏 ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, var(--panel-strong), var(--panel));
  box-shadow: 0 12px 34px rgba(2, 6, 23, 0.32);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border-radius: 14px;
  color: var(--accent-ink);
  background: linear-gradient(135deg, var(--accent-3), var(--accent), var(--accent-2));
  box-shadow: 0 8px 22px rgba(56, 189, 248, 0.3);
}

.brand-mark svg {
  width: 24px;
  height: 24px;
}

.brand-text {
  min-width: 0;
}

.brand-text h1 {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.brand-text p {
  margin: 1px 0 0;
  color: var(--muted);
  font-size: 12px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}

.model-picker {
  position: relative;
  display: block;
}

.model-picker::after {
  content: "";
  position: absolute;
  top: 50%;
  right: 14px;
  width: 6px;
  height: 6px;
  border-right: 1.6px solid var(--muted);
  border-bottom: 1.6px solid var(--muted);
  transform: translateY(-72%) rotate(45deg);
  pointer-events: none;
}

.model-picker select {
  max-width: 230px;
  padding: 9px 34px 9px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--panel-soft);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: border-color 0.18s ease, background 0.18s ease;
}

.model-picker select:hover {
  border-color: var(--border-strong);
  background: rgba(148, 163, 184, 0.1);
}

.ghost-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.ghost-btn svg {
  width: 16px;
  height: 16px;
}

.ghost-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--panel-soft);
}

/* ---------- 对话区 ---------- */
.chat {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  gap: 18px;
  min-height: 0;
  padding: 10px 4px 6px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: rgba(148, 163, 184, 0.28) transparent;
}

.chat::-webkit-scrollbar {
  width: 8px;
}

.chat::-webkit-scrollbar-thumb {
  border: 2px solid transparent;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.28);
  background-clip: content-box;
}

.welcome {
  max-width: 660px;
  margin: auto;
  padding: 16px 8px;
  text-align: center;
  animation: fade-up 0.5s ease both;
}

.welcome-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid rgba(52, 211, 153, 0.22);
  border-radius: 999px;
  background: rgba(52, 211, 153, 0.08);
  color: #a7f3d0;
  font-size: 12px;
  letter-spacing: 0.02em;
}

.pulse-dot {
  position: relative;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.5);
  animation: pulse-ring 2s ease-out infinite;
}

.welcome h2 {
  margin: 20px 0 10px;
  font-size: clamp(30px, 5.2vw, 46px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  background: linear-gradient(100deg, #f8fbff 12%, #7dd3fc 52%, #a5b4fc 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.welcome-sub {
  max-width: 520px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 14.5px;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 26px;
}

.chip {
  padding: 9px 15px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--panel-soft);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease,
    box-shadow 0.18s ease;
}

.chip:hover {
  transform: translateY(-2px);
  border-color: rgba(56, 189, 248, 0.45);
  background: rgba(56, 189, 248, 0.1);
  box-shadow: 0 8px 20px rgba(56, 189, 248, 0.12);
}

.chip:active {
  transform: translateY(0);
}

.welcome-foot {
  margin: 26px 0 0;
  color: var(--muted-2);
  font-size: 12px;
}

/* ---------- 消息 ---------- */
.msg {
  display: flex;
  gap: 11px;
  max-width: 86%;
  animation: fade-up 0.28s ease both;
}

.msg-user {
  flex-direction: row-reverse;
  margin-left: auto;
}

.msg-assistant {
  margin-right: auto;
}

.msg-avatar {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
  border-radius: 11px;
  color: var(--avatar-ink);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
  user-select: none;
}

.msg-user .msg-avatar {
  background: linear-gradient(135deg, var(--accent-3), var(--accent));
  box-shadow: 0 6px 16px rgba(56, 189, 248, 0.24);
}

.msg-assistant .msg-avatar {
  background: linear-gradient(135deg, var(--accent-2), #c084fc);
  box-shadow: 0 6px 16px rgba(129, 140, 248, 0.24);
}

.msg-body {
  min-width: 0;
}

.msg-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 20px;
  margin-bottom: 5px;
  color: var(--muted-2);
  font-size: 11.5px;
  letter-spacing: 0.02em;
}

.msg-user .msg-meta {
  justify-content: flex-end;
}

.msg-name {
  color: var(--muted);
  font-weight: 600;
}

.msg-content {
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--panel);
  font-size: 14.5px;
  line-height: 1.72;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.msg-user .msg-content {
  border-color: rgba(56, 189, 248, 0.26);
  border-top-right-radius: 6px;
  background: linear-gradient(
    135deg,
    rgba(56, 189, 248, 0.18),
    rgba(129, 140, 248, 0.18)
  );
}

.msg-assistant .msg-content {
  border-top-left-radius: 6px;
}

.msg.is-streaming .msg-content:empty::before {
  content: "正在思考";
  color: var(--muted);
  animation: pulse-text 1.4s ease-in-out infinite;
}

.msg.is-streaming .msg-content::after {
  content: "▍";
  margin-left: 2px;
  color: var(--accent);
  animation: blink 1s steps(1) infinite;
}

.msg.is-stopped .msg-content {
  border-color: rgba(251, 191, 36, 0.24);
}

.msg.is-stopped .msg-meta::after {
  content: "已停止";
  color: #fcd34d;
  font-size: 11px;
}

.msg.is-error .msg-content {
  border-color: rgba(251, 113, 133, 0.28);
}

.msg.is-error .msg-meta::after {
  content: "已中断";
  color: var(--danger);
  font-size: 11px;
}

.msg-usage {
  color: var(--muted-2);
  font-variant-numeric: tabular-nums;
}


.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
  padding: 2px 6px;
  border: 1px solid transparent;
  border-radius: 7px;
  background: transparent;
  color: var(--muted-2);
  font-size: 11px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s ease, color 0.15s ease, border-color 0.15s ease,
    background 0.15s ease;
}

.msg:hover .copy-btn,
.copy-btn:focus-visible {
  opacity: 1;
}

.copy-btn svg {
  width: 13px;
  height: 13px;
}

.copy-btn:hover {
  color: var(--text);
  border-color: var(--border);
  background: var(--panel-soft);
}

.notice {
  align-self: center;
  max-width: min(560px, 92%);
  padding: 10px 15px;
  border: 1px solid rgba(251, 113, 133, 0.3);
  border-radius: var(--radius-sm);
  background: rgba(251, 113, 133, 0.09);
  color: #fecdd3;
  font-size: 13.5px;
  text-align: center;
  animation: fade-up 0.25s ease both;
}

.notice strong {
  color: #fda4af;
}

/* ---------- 输入区 ---------- */
.composer-wrap {
  flex: 0 0 auto;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

.composer {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  padding: 9px 9px 9px 16px;
  border: 1px solid var(--border-strong);
  border-radius: 20px;
  background: var(--panel-strong);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.composer:focus-within {
  border-color: rgba(56, 189, 248, 0.55);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.08), var(--shadow);
}

#prompt {
  flex: 1 1 auto;
  min-height: 28px;
  max-height: 180px;
  padding: 6px 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
  resize: none;
  scrollbar-width: thin;
}

#prompt::placeholder {
  color: var(--muted-2);
}

#prompt:disabled {
  opacity: 0.6;
}

.send-btn {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  flex: 0 0 auto;
  border: 0;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--accent-3), var(--accent), var(--accent-2));
  color: var(--accent-ink);
  cursor: pointer;
  box-shadow: 0 8px 22px rgba(56, 189, 248, 0.28);
  transition: transform 0.16s ease, box-shadow 0.16s ease, filter 0.16s ease;
}

.send-btn svg {
  width: 20px;
  height: 20px;
}

.send-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  filter: brightness(1.06);
  box-shadow: 0 10px 26px rgba(56, 189, 248, 0.36);
}

.send-btn:active:not(:disabled) {
  transform: translateY(0);
}

.send-btn:disabled {
  cursor: not-allowed;
  opacity: 0.5;
  box-shadow: none;
}

.stop-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 15px;
  flex: 0 0 auto;
  border: 1px solid rgba(251, 113, 133, 0.4);
  border-radius: 14px;
  background: rgba(251, 113, 133, 0.1);
  color: #fecdd3;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.16s ease, border-color 0.16s ease;
}

.stop-btn:hover {
  background: rgba(251, 113, 133, 0.18);
  border-color: rgba(251, 113, 133, 0.6);
}

.stop-square {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  background: currentColor;
}

body.is-busy .send-btn {
  display: none;
}

.composer-meta {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-top: 9px;
  padding: 0 6px;
}

.settings {
  min-width: 0;
}

.settings summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 12.5px;
  cursor: pointer;
  user-select: none;
  transition: color 0.15s ease;
}

.settings summary:hover {
  color: var(--text);
}

.settings-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 12px;
  width: min(460px, 86vw);
  margin-top: 10px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--panel-strong);
  box-shadow: 0 16px 40px rgba(2, 6, 23, 0.3);
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
  color: var(--muted);
  font-size: 12px;
}

.field-full {
  grid-column: 1 / -1;
}

.field span {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.field output {
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.field textarea,
.field input[type="number"] {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel-soft);
  color: var(--text);
  font-size: 13px;
  line-height: 1.5;
}

.field textarea {
  resize: vertical;
  min-height: 64px;
}

.field textarea:focus,
.field input[type="number"]:focus {
  outline: none;
  border-color: rgba(56, 189, 248, 0.5);
}

.field input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.switch {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: end;
  padding-bottom: 4px;
  color: var(--muted);
  font-size: 12.5px;
  cursor: pointer;
}

.switch input {
  width: 15px;
  height: 15px;
  accent-color: var(--accent);
  cursor: pointer;
}

.hint {
  margin: 0;
  color: var(--muted-2);
  font-size: 11.5px;
  text-align: right;
}

/* ---------- 提示 ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  z-index: 50;
  padding: 9px 16px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  background: var(--panel-strong);
  color: var(--text);
  font-size: 13px;
  box-shadow: 0 14px 40px rgba(2, 6, 23, 0.45);
  opacity: 0;
  transform: translate(-50%, 12px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ---------- 动画 ---------- */
@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes blink {
  0%,
  49% {
    opacity: 1;
  }
  50%,
  100% {
    opacity: 0;
  }
}

@keyframes pulse-ring {
  0% {
    box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.45);
  }
  70% {
    box-shadow: 0 0 0 7px rgba(52, 211, 153, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(52, 211, 153, 0);
  }
}

@keyframes pulse-text {
  0%,
  100% {
    opacity: 0.45;
  }
  50% {
    opacity: 1;
  }
}

/* ---------- 浅色主题 ---------- */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f3f7fd;
    --panel: rgba(255, 255, 255, 0.82);
    --panel-strong: rgba(255, 255, 255, 0.95);
    --panel-soft: rgba(15, 23, 42, 0.04);
    --border: rgba(15, 23, 42, 0.1);
    --border-strong: rgba(15, 23, 42, 0.18);
    --text: #0f1b2d;
    --muted: #5a6b82;
    --muted-2: #8494a9;
    --shadow: 0 20px 50px rgba(30, 64, 175, 0.12);
  }

  body::before {
    background:
      radial-gradient(58rem 38rem at 12% -12%, rgba(56, 189, 248, 0.2), transparent 62%),
      radial-gradient(48rem 34rem at 98% 8%, rgba(129, 140, 248, 0.16), transparent 60%),
      radial-gradient(44rem 30rem at 52% 112%, rgba(34, 211, 238, 0.12), transparent 62%);
  }

  body::after {
    background-image:
      linear-gradient(rgba(15, 23, 42, 0.035) 1px, transparent 1px),
      linear-gradient(90deg, rgba(15, 23, 42, 0.035) 1px, transparent 1px);
  }

  .topbar {
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.8));
    box-shadow: 0 12px 34px rgba(30, 64, 175, 0.08);
  }

  .welcome h2 {
    background: linear-gradient(100deg, #0f1b2d 12%, #0284c7 52%, #4f46e5 90%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  .welcome-badge {
    border-color: rgba(5, 150, 105, 0.2);
    background: rgba(16, 185, 129, 0.08);
    color: #047857;
  }

  .msg-user .msg-content {
    border-color: rgba(14, 165, 233, 0.22);
    background: linear-gradient(
      135deg,
      rgba(56, 189, 248, 0.16),
      rgba(129, 140, 248, 0.14)
    );
  }

  .notice {
    border-color: rgba(225, 29, 72, 0.2);
    background: rgba(244, 63, 94, 0.07);
    color: #be123c;
  }

  .notice strong {
    color: #9f1239;
  }

  .stop-btn {
    border-color: rgba(225, 29, 72, 0.28);
    background: rgba(244, 63, 94, 0.06);
    color: #be123c;
  }

  .stop-btn:hover {
    background: rgba(244, 63, 94, 0.12);
    border-color: rgba(225, 29, 72, 0.45);
  }

  .toast {
    box-shadow: 0 14px 40px rgba(30, 64, 175, 0.16);
  }

  .msg.is-stopped .msg-meta::after {
    color: #b45309;
  }
}

/* ---------- 响应式 ---------- */
@media (max-width: 640px) {
  .app {
    padding: 10px 10px 8px;
    gap: 8px;
  }

  .topbar {
    flex-wrap: wrap;
    gap: 10px;
    padding: 11px 12px;
    border-radius: 18px;
  }

  .brand-text p {
    display: none;
  }

  .topbar-actions {
    width: 100%;
  }

  .model-picker {
    flex: 1 1 auto;
  }

  .model-picker select {
    width: 100%;
    max-width: none;
  }

  .chat {
    gap: 14px;
    padding-top: 4px;
  }

  .welcome {
    margin: 0 auto;
    padding: 8px 2px 16px;
  }

  .welcome h2 {
    margin-top: 16px;
  }

  .chips {
    margin-top: 20px;
  }

  .chip {
    padding: 8px 12px;
    font-size: 12.5px;
  }

  .msg {
    max-width: 94%;
    gap: 8px;
  }

  .msg-avatar {
    width: 30px;
    height: 30px;
    border-radius: 10px;
    font-size: 11px;
  }

  .msg-content {
    padding: 10px 13px;
    font-size: 14px;
  }

  .copy-btn {
    opacity: 1;
  }

  .composer {
    padding-left: 13px;
    border-radius: 17px;
  }

  .composer-meta {
    flex-direction: column;
    gap: 8px;
  }

  .settings {
    width: 100%;
  }

  .settings-body {
    width: 100%;
    grid-template-columns: minmax(0, 1fr);
  }

  .hint {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}