:root {
  color-scheme: light;
  --bg: #f7f7f5;
  --panel: #ffffff;
  --sidebar: #f0f1ee;
  --sidebar-hover: #e5e7e2;
  --text: #20211f;
  --muted: #73766f;
  --subtle: #989c94;
  --line: #e1e3de;
  --accent: #2f6d5b;
  --accent-hover: #275d4e;
  --accent-soft: #e3efea;
  --assistant: #ffffff;
  --user: #e8eee9;
  --shadow: 0 12px 36px rgba(28, 36, 31, 0.08);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #20211f;
  --panel: #262825;
  --sidebar: #181a18;
  --sidebar-hover: #292c29;
  --text: #eceee9;
  --muted: #a8aca4;
  --subtle: #7f847c;
  --line: #393c38;
  --accent: #75b69f;
  --accent-hover: #8bc5b0;
  --accent-soft: #293e36;
  --assistant: #262825;
  --user: #343b36;
  --shadow: 0 12px 36px rgba(0, 0, 0, 0.22);
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
}

body {
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  transition: background 180ms ease, color 180ms ease;
}

button,
textarea {
  font: inherit;
}

button {
  color: inherit;
}

.app-shell {
  display: flex;
  width: 100%;
  height: 100%;
}

.sidebar {
  z-index: 20;
  display: flex;
  flex: 0 0 272px;
  flex-direction: column;
  height: 100%;
  padding: 18px 14px;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 2px 5px 18px;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: #f5f8f4;
  background: var(--accent);
  border-radius: 11px;
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 22px;
}

.brand-name {
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.brand-subtitle {
  margin-top: 2px;
  color: var(--muted);
  font-size: 11px;
}

.icon-button {
  display: grid;
  width: 36px;
  height: 36px;
  padding: 0;
  place-items: center;
  background: transparent;
  border: 0;
  border-radius: 9px;
  cursor: pointer;
}

.icon-button:hover {
  background: var(--sidebar-hover);
}

.sidebar-close,
.menu-button {
  display: none;
}

.new-chat-button {
  display: flex;
  align-items: center;
  gap: 9px;
  width: 100%;
  padding: 11px 13px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(30, 38, 33, 0.03);
  cursor: pointer;
}

.new-chat-button:hover {
  border-color: var(--accent);
}

.new-chat-button span,
.knowledge-button span {
  color: var(--accent);
  font-size: 20px;
  line-height: 1;
}

.knowledge-button {
  display: flex;
  align-items: center;
  gap: 9px;
  width: 100%;
  margin-top: 8px;
  padding: 10px 13px;
  color: var(--muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 11px;
  cursor: pointer;
}

.knowledge-button:hover {
  color: var(--text);
  background: var(--sidebar-hover);
}

.sidebar-section {
  margin-top: 28px;
}

.section-label {
  padding: 0 10px 8px;
  color: var(--subtle);
  font-size: 12px;
}

.prompt-example {
  width: 100%;
  padding: 10px;
  overflow: hidden;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 9px;
  text-align: left;
  text-overflow: ellipsis;
  white-space: nowrap;
  cursor: pointer;
}

.prompt-example:hover {
  color: var(--text);
  background: var(--sidebar-hover);
}

.sidebar-footer {
  margin-top: auto;
}

.local-note {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px;
  color: var(--muted);
  font-size: 12px;
}

.status-dot,
.model-dot {
  width: 7px;
  height: 7px;
  background: #51a87d;
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(81, 168, 125, 0.12);
}

.theme-button {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 9px;
  cursor: pointer;
}

.theme-button:hover {
  color: var(--text);
  background: var(--sidebar-hover);
}

.main-panel {
  position: relative;
  display: flex;
  min-width: 0;
  flex: 1;
  flex-direction: column;
  background:
    radial-gradient(circle at 50% 18%, rgba(79, 132, 108, 0.055), transparent 34%),
    var(--bg);
}

.topbar {
  z-index: 5;
  display: flex;
  height: 58px;
  flex: 0 0 58px;
  align-items: center;
  padding: 0 24px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(12px);
}

.topbar-title {
  font-size: 14px;
  font-weight: 600;
}

.model-badge {
  display: flex;
  align-items: center;
  gap: 7px;
  margin-left: auto;
  padding: 7px 10px;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 12px;
}

.conversation {
  flex: 1;
  overflow-y: auto;
  scroll-behavior: smooth;
}

.welcome {
  display: flex;
  width: min(720px, calc(100% - 40px));
  min-height: calc(100% - 12px);
  margin: 0 auto;
  padding: 48px 0 138px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.welcome-seal {
  display: grid;
  width: 54px;
  height: 54px;
  margin-bottom: 22px;
  place-items: center;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
  border-radius: 17px;
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 29px;
}

.welcome h1 {
  margin: 0;
  font-family: "STSong", "SimSun", serif;
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 500;
  letter-spacing: 0.08em;
}

.welcome > p {
  max-width: 520px;
  margin: 17px auto 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.suggestion-grid {
  display: grid;
  width: 100%;
  margin-top: 34px;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.suggestion-card {
  padding: 17px 18px;
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 15px;
  box-shadow: 0 3px 14px rgba(35, 42, 38, 0.025);
  text-align: left;
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.suggestion-card:hover {
  border-color: color-mix(in srgb, var(--accent) 55%, var(--line));
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.suggestion-title {
  display: block;
  margin-bottom: 8px;
  color: var(--text);
  font-weight: 600;
}

.messages {
  width: min(820px, calc(100% - 40px));
  margin: 0 auto;
  padding: 28px 0 150px;
}

.message {
  display: flex;
  margin-bottom: 27px;
  gap: 13px;
}

.message.user {
  justify-content: flex-end;
}

.message-avatar {
  display: grid;
  width: 31px;
  height: 31px;
  flex: 0 0 31px;
  place-items: center;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 9px;
  font-family: "STKaiti", "KaiTi", serif;
  font-size: 17px;
}

.message-content {
  min-width: 0;
  max-width: min(680px, calc(100% - 44px));
}

.message.user .message-content {
  padding: 11px 15px;
  background: var(--user);
  border-radius: 16px 16px 4px 16px;
}

.message-text {
  font-size: 15px;
  line-height: 1.85;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}

.message-status {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  font-size: 13px;
}

.thinking-dot {
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 1.2s infinite ease-in-out;
}

.selection-card {
  display: flex;
  margin-bottom: 14px;
  padding: 10px 12px;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 18%, transparent);
  border-radius: 10px;
  font-size: 12px;
}

.selection-name {
  color: var(--accent);
  font-weight: 700;
}

.selection-score {
  margin-left: auto;
  font-variant-numeric: tabular-nums;
}

.message-actions {
  display: flex;
  margin-top: 9px;
  gap: 4px;
}

.copy-button {
  padding: 4px 8px;
  color: var(--subtle);
  background: transparent;
  border: 0;
  border-radius: 7px;
  font-size: 12px;
  cursor: pointer;
}

.copy-button:hover {
  color: var(--text);
  background: var(--sidebar-hover);
}

.composer-area {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 8;
  padding: 28px 22px 13px;
  background: linear-gradient(to bottom, transparent, var(--bg) 26%, var(--bg));
}

.composer {
  display: flex;
  width: min(820px, 100%);
  min-height: 58px;
  margin: 0 auto;
  padding: 9px 9px 9px 17px;
  align-items: flex-end;
  gap: 10px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  transition: border-color 160ms ease, box-shadow 160ms ease;
}

.composer:focus-within {
  border-color: color-mix(in srgb, var(--accent) 62%, var(--line));
  box-shadow: 0 12px 38px rgba(43, 91, 73, 0.11);
}

.composer textarea {
  width: 100%;
  max-height: 180px;
  padding: 8px 0;
  resize: none;
  color: var(--text);
  background: transparent;
  border: 0;
  outline: none;
  line-height: 1.5;
}

.composer textarea::placeholder {
  color: var(--subtle);
}

.send-button {
  display: grid;
  width: 39px;
  height: 39px;
  flex: 0 0 39px;
  padding: 0;
  place-items: center;
  color: #ffffff;
  background: var(--accent);
  border: 0;
  border-radius: 12px;
  font-size: 21px;
  cursor: pointer;
}

.send-button:hover:not(:disabled) {
  background: var(--accent-hover);
}

.send-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.send-button.stop {
  font-size: 13px;
}

.composer-hint {
  margin-top: 8px;
  color: var(--subtle);
  font-size: 11px;
  text-align: center;
}

.sidebar-overlay {
  display: none;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  padding: 24px;
  place-items: center;
  background: rgba(19, 22, 20, 0.52);
  backdrop-filter: blur(4px);
}

.modal-backdrop[hidden] {
  display: none;
}

.knowledge-modal {
  width: min(680px, 100%);
  max-height: calc(100vh - 48px);
  padding: 24px;
  overflow-y: auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.22);
}

.modal-header {
  display: flex;
  align-items: flex-start;
  gap: 18px;
}

.modal-header h2 {
  margin: 0;
  font-family: "STSong", "SimSun", serif;
  font-size: 22px;
  font-weight: 600;
}

.modal-header p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.modal-header .icon-button {
  margin-left: auto;
  flex: 0 0 36px;
  font-size: 22px;
}

.form-grid {
  display: grid;
  margin-top: 24px;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.field {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 7px;
}

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

.field > span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

.field b {
  color: #b24a42;
}

.field input,
.field textarea {
  width: 100%;
  padding: 10px 12px;
  resize: vertical;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 10px;
  outline: none;
  line-height: 1.55;
}

.field input:focus,
.field textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 12%, transparent);
}

.field input::placeholder,
.field textarea::placeholder {
  color: var(--subtle);
}

.form-message {
  min-height: 20px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 12px;
}

.form-message.success {
  color: var(--accent);
}

.form-message.error {
  color: #b24a42;
}

.modal-actions {
  display: flex;
  margin-top: 4px;
  justify-content: flex-end;
  gap: 10px;
}

.primary-button,
.secondary-button {
  padding: 10px 15px;
  border-radius: 10px;
  cursor: pointer;
}

.primary-button {
  color: #ffffff;
  background: var(--accent);
  border: 1px solid var(--accent);
}

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

.primary-button:disabled {
  cursor: wait;
  opacity: 0.6;
}

.secondary-button {
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
}

.secondary-button:hover {
  color: var(--text);
  background: var(--sidebar-hover);
}

@keyframes pulse {
  0%, 100% { opacity: 0.35; transform: scale(0.85); }
  50% { opacity: 1; transform: scale(1.05); }
}

@media (max-width: 760px) {
  .sidebar {
    position: fixed;
    width: min(286px, 86vw);
    transform: translateX(-102%);
    transition: transform 180ms ease;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay.visible {
    position: fixed;
    inset: 0;
    z-index: 15;
    display: block;
    background: rgba(0, 0, 0, 0.35);
  }

  .sidebar-close {
    display: grid;
    margin-left: auto;
  }

  .menu-button {
    display: grid;
    margin-right: 8px;
  }

  .topbar {
    padding: 0 14px;
  }

  .welcome {
    width: calc(100% - 28px);
    padding-bottom: 156px;
  }

  .suggestion-grid {
    grid-template-columns: 1fr;
  }

  .messages {
    width: calc(100% - 28px);
  }

  .composer-area {
    padding-right: 10px;
    padding-left: 10px;
  }

  .composer-hint {
    font-size: 10px;
  }

  .modal-backdrop {
    padding: 10px;
  }

  .knowledge-modal {
    max-height: calc(100vh - 20px);
    padding: 19px;
    border-radius: 16px;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .field.full-width {
    grid-column: auto;
  }
}

@media (max-width: 430px) {
  .model-badge {
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .welcome h1 {
    font-size: 27px;
  }
}