:root {
  /* 统一维护主题色，方便后续按品牌或偏好调整。 */
  --bg: #f6f8fb;
  --surface: rgba(255, 255, 255, 0.92);
  --surface-solid: #ffffff;
  --surface-soft: #f1f5f9;
  --text: #162033;
  --muted: #667085;
  --line: #d9e2ec;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --accent: #0f766e;
  --accent-soft: #e6f4f1;
  --danger: #b42318;
  --danger-bg: #fff1f0;
  --danger-line: #fecdca;
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  --shadow-hover: 0 22px 54px rgba(15, 23, 42, 0.12);
  --radius: 8px;
}

body.dark-theme {
  --bg: #10141f;
  --surface: rgba(24, 31, 46, 0.92);
  --surface-solid: #182033;
  --surface-soft: #222b3f;
  --text: #eef4ff;
  --muted: #aab6cb;
  --line: #314057;
  --primary: #70a5ff;
  --primary-strong: #4b8cff;
  --accent: #5eead4;
  --accent-soft: rgba(94, 234, 212, 0.12);
  --danger: #ffb4ac;
  --danger-bg: rgba(180, 35, 24, 0.18);
  --danger-line: rgba(254, 205, 202, 0.35);
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.28);
  --shadow-hover: 0 24px 64px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  color: var(--text);
  background:
    linear-gradient(180deg, rgba(219, 234, 254, 0.78) 0%, rgba(246, 248, 251, 0) 330px),
    radial-gradient(circle at 10% 0%, rgba(20, 184, 166, 0.12), transparent 260px),
    var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  transition: background-color 0.25s ease, color 0.25s ease;
}

body.dark-theme {
  background:
    linear-gradient(180deg, rgba(37, 99, 235, 0.18) 0%, rgba(16, 20, 31, 0) 330px),
    radial-gradient(circle at 10% 0%, rgba(94, 234, 212, 0.12), transparent 260px),
    var(--bg);
}

button,
input,
textarea {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

button svg {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}

.app-shell {
  width: min(1220px, calc(100% - 32px));
  min-height: 100dvh;
  margin: 0 auto;
  padding: clamp(18px, 3vw, 34px) 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 24px;
  margin-bottom: 22px;
  animation: riseIn 0.5s ease both;
}

.hero-actions {
  display: flex;
  gap: 10px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 10px;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 2px;
  font-size: 1rem;
}

.intro {
  max-width: 840px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1rem;
}

.panel {
  /* 主要内容面板采用轻卡片风格，保持 Notion/ChatGPT 式的干净层次。 */
  background: var(--surface);
  border: 1px solid color-mix(in srgb, var(--line) 82%, transparent);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.panel:hover {
  box-shadow: var(--shadow-hover);
}

.api-panel,
.input-panel,
.conversation-panel {
  padding: clamp(16px, 2vw, 20px);
}

.api-panel {
  margin-bottom: 16px;
  animation: riseIn 0.52s 0.06s ease both;
}

.section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.section-heading p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.status-pill,
.mini-stat {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
  white-space: nowrap;
}

.status-pill.is-ready {
  background: var(--accent-soft);
  color: var(--accent);
}

.api-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-solid);
  color: var(--text);
  outline: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

input {
  min-height: 46px;
  padding: 0 14px;
}

textarea {
  min-height: clamp(180px, 28dvh, 320px);
  max-height: 44dvh;
  padding: 14px;
  resize: none;
  overflow-y: hidden;
}

input::placeholder,
textarea::placeholder {
  color: color-mix(in srgb, var(--muted) 74%, transparent);
}

input:focus,
textarea:focus {
  border-color: color-mix(in srgb, var(--primary) 80%, white);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 16%, transparent);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(320px, 0.86fr) minmax(0, 1.14fr);
  align-items: stretch;
  gap: 16px;
  min-height: min(720px, calc(100dvh - 246px));
}

.input-panel {
  animation: riseIn 0.54s 0.12s ease both;
}

.conversation-panel {
  display: flex;
  flex-direction: column;
  min-height: min(720px, calc(100dvh - 246px));
  animation: riseIn 0.56s 0.18s ease both;
}

.quick-prompts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.action-bar,
.tool-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.tool-row {
  margin-top: 0;
  margin-bottom: 14px;
}

.primary-button,
.secondary-button,
.ghost-button,
.tool-button,
.chip-button,
.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  border-radius: var(--radius);
  padding: 0 14px;
  font-weight: 700;
  transition: transform 0.18s ease, background-color 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}

.primary-button {
  min-height: 46px;
  background: var(--primary);
  color: #fff;
  box-shadow: 0 10px 22px color-mix(in srgb, var(--primary) 32%, transparent);
}

.secondary-button {
  min-height: 46px;
  background: #162033;
  color: #fff;
}

body.dark-theme .secondary-button {
  background: #eef4ff;
  color: #111827;
}

.ghost-button,
.tool-button,
.chip-button,
.icon-button {
  border: 1px solid var(--line);
  background: var(--surface-solid);
  color: var(--text);
}

.icon-button {
  width: 44px;
  padding: 0;
}

.chip-button {
  min-height: 34px;
  padding: 0 12px;
  color: var(--accent);
  background: var(--accent-soft);
  border-color: color-mix(in srgb, var(--accent) 24%, transparent);
  font-size: 0.9rem;
}

.tool-button {
  min-height: 38px;
  font-size: 0.9rem;
}

.primary-button:hover:not(:disabled),
.secondary-button:hover:not(:disabled),
.ghost-button:hover:not(:disabled),
.tool-button:hover:not(:disabled),
.chip-button:hover:not(:disabled),
.icon-button:hover:not(:disabled) {
  transform: translateY(-2px);
}

.primary-button:hover:not(:disabled) {
  background: var(--primary-strong);
}

.secondary-button:hover:not(:disabled) {
  background: #243047;
}

body.dark-theme .secondary-button:hover:not(:disabled) {
  background: #dbe8ff;
}

.ghost-button:hover:not(:disabled),
.tool-button:hover:not(:disabled),
.icon-button:hover:not(:disabled) {
  background: var(--surface-soft);
}

.chip-button:hover:not(:disabled) {
  border-color: color-mix(in srgb, var(--accent) 56%, transparent);
  box-shadow: 0 8px 18px color-mix(in srgb, var(--accent) 16%, transparent);
}

.loading {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
  color: var(--primary-strong);
  font-weight: 700;
}

.spinner {
  /* 请求期间的轻量旋转加载指示器。 */
  width: 20px;
  height: 20px;
  border: 3px solid color-mix(in srgb, var(--primary) 18%, transparent);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.82s linear infinite;
}

.error-box {
  margin-bottom: 16px;
  padding: 12px 14px;
  border: 1px solid var(--danger-line);
  border-radius: var(--radius);
  background: var(--danger-bg);
  color: var(--danger);
  font-weight: 700;
  animation: shakeIn 0.28s ease both;
}

.conversation-list {
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  gap: 14px;
  min-height: 360px;
  overflow-y: auto;
  padding-right: 4px;
  scroll-behavior: smooth;
}

.empty-state {
  display: grid;
  place-items: center;
  min-height: 340px;
  padding: 24px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  text-align: center;
}

.empty-state strong {
  color: var(--text);
}

.message {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface-solid);
  animation: messageIn 0.26s ease both;
}

.message.user {
  border-color: #c7d2fe;
  background: color-mix(in srgb, #eef2ff 62%, var(--surface-solid));
}

.message.assistant {
  border-color: color-mix(in srgb, var(--accent) 34%, var(--line));
}

body.dark-theme .message.user {
  border-color: #5364b3;
  background: rgba(67, 78, 138, 0.18);
}

.message-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface-soft) 76%, transparent);
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.message.user .message-header {
  color: #3730a3;
}

.message.assistant .message-header {
  color: var(--accent);
}

body.dark-theme .message.user .message-header {
  color: #b8c2ff;
}

.message-body {
  padding: 14px;
  overflow-x: auto;
}

.message-body p:last-child,
.message-body ul:last-child,
.message-body ol:last-child,
.message-body table:last-child {
  margin-bottom: 0;
}

.message-body pre {
  overflow-x: auto;
  padding: 12px;
  border-radius: var(--radius);
  background: #0f172a;
  color: #e2e8f0;
}

.message-body code {
  padding: 2px 5px;
  border-radius: 4px;
  background: var(--surface-soft);
  color: var(--primary-strong);
}

.message-body pre code {
  padding: 0;
  background: transparent;
  color: inherit;
}

.message-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0;
  font-size: 0.94rem;
}

.message-body th,
.message-body td {
  border: 1px solid var(--line);
  padding: 9px 10px;
  vertical-align: top;
}

.message-body th {
  background: color-mix(in srgb, var(--primary) 10%, var(--surface-soft));
  text-align: left;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 10;
  max-width: min(360px, calc(100% - 36px));
  padding: 12px 14px;
  border: 1px solid color-mix(in srgb, var(--accent) 26%, transparent);
  border-radius: var(--radius);
  background: var(--surface-solid);
  color: var(--text);
  box-shadow: var(--shadow-hover);
  animation: toastIn 0.22s ease both;
}

.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;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes messageIn {
  from {
    opacity: 0;
    transform: translateY(8px) scale(0.99);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes shakeIn {
  0% {
    transform: translateX(-4px);
  }
  50% {
    transform: translateX(4px);
  }
  100% {
    transform: translateX(0);
  }
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 940px) {
  /* 中小屏切换为单列，避免输入区和结果区被压缩。 */
  .app-shell {
    width: min(100% - 22px, 720px);
  }

  .hero,
  .workspace,
  .api-row {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    justify-content: flex-start;
  }

  .conversation-panel {
    min-height: 520px;
  }

  .conversation-list {
    min-height: 320px;
  }
}

@media (max-width: 560px) {
  /* 手机窄屏上减少留白并让按钮自然铺满宽度。 */
  .app-shell {
    width: min(100% - 18px, 520px);
    padding: 16px 0;
  }

  h1 {
    font-size: 2rem;
  }

  .api-panel,
  .input-panel,
  .conversation-panel {
    padding: 16px;
  }

  .section-heading,
  .conversation-heading {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .secondary-button,
  .primary-button,
  .ghost-button,
  .tool-button {
    width: 100%;
  }

  textarea {
    max-height: 50dvh;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}