:root {
  color-scheme: light;
  --bg: #eef1f5;
  --panel: #ffffff;
  --panel-soft: #f8fafc;
  --border: #dde3ea;
  --border-strong: #cfd7e3;
  --text: #15202b;
  --muted: #6d7b8a;
  --accent: #2b6df6;
  --accent-strong: #1f5bd4;
  --user: #2b6df6;
  --model: #eef3f8;
  --danger: #c25151;
  --shadow: 0 12px 32px rgba(16, 24, 40, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  overflow: hidden;
  font-family: 'Noto Sans TC', sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f5f7fb, #edf1f6);
}

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr) 360px;
  gap: 16px;
  height: 100vh;
  padding: 16px;
}

.sidebar,
.chat-panel,
.settings-panel {
  min-height: 0;
  border: 1px solid var(--border);
  border-radius: 22px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 16px;
}

.brand-card,
.summary-card,
.control-card,
.memory-card,
.settings-card,
.prompt-file {
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--panel-soft);
  padding: 14px;
}

.brand-card {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 18px;
  background: #dce8ff;
  color: var(--accent-strong);
  font-size: 24px;
  font-weight: 700;
}

.eyebrow,
.card-label,
.message-meta {
  margin: 0;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1,
h2,
h3 {
  font-weight: 700;
}

h1 {
  font-size: 22px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

.presence {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-top: 4px;
  color: var(--muted);
  font-size: 14px;
}

.presence span {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #31c06a;
}

.summary-card.compact p:last-child {
  margin-top: 6px;
  color: var(--muted);
}

.control-card,
.memory-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  border-radius: 999px;
  padding: 6px 10px;
  background: #e6edf7;
  color: #415365;
  font-size: 13px;
}

.second {
  margin-top: 8px;
}

.chat-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 20px;
  border-bottom: 1px solid var(--border);
}

.chat-meta {
  display: flex;
  gap: 8px;
  align-items: center;
}

.pill {
  border-radius: 999px;
  padding: 8px 12px;
  background: #edf3ff;
  color: var(--accent-strong);
  font-size: 13px;
}

.pill.soft {
  background: #f1f4f7;
  color: var(--muted);
}

.messages {
  min-height: 0;
  overflow-y: auto;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  background: linear-gradient(180deg, #fbfcfe, #f4f7fb);
}

.message-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-width: 72%;
}

.message-row.user {
  margin-left: auto;
  align-items: flex-end;
}

.bubble-stack {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.bubble {
  width: fit-content;
  max-width: 100%;
  padding: 11px 14px;
  border-radius: 18px;
  line-height: 1.45;
  white-space: pre-wrap;
  word-break: break-word;
}

.message-row.user .bubble {
  margin-left: auto;
  background: var(--user);
  color: #fff;
  border-bottom-right-radius: 6px;
}

.message-row.model .bubble {
  background: var(--model);
  color: var(--text);
  border: 1px solid #dbe5ef;
  border-bottom-left-radius: 6px;
}

.composer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
  padding: 16px 20px 20px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}

.composer-tools {
  grid-column: 1 / -1;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.ghost-button.active {
  background: #dce8ff;
  color: var(--accent-strong);
}

textarea,
input {
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: 16px;
  background: #fff;
  color: var(--text);
  padding: 12px 14px;
  font: inherit;
}

textarea {
  min-height: 52px;
  resize: vertical;
}

button {
  border: 0;
  border-radius: 14px;
  font: inherit;
  cursor: pointer;
  transition: background 160ms ease, opacity 160ms ease;
}

.accent-button,
.send-button {
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
}

.accent-button:hover,
.send-button:hover {
  background: var(--accent-strong);
}

.ghost-button {
  padding: 12px 14px;
  background: #eef2f6;
  color: var(--text);
}

.ghost-button.danger {
  color: var(--danger);
}

.full {
  width: 100%;
}

.settings-panel {
  min-height: 0;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.settings-header {
  margin-bottom: 12px;
}

.settings-card label {
  display: block;
  margin-bottom: 12px;
  color: var(--muted);
}

.button-row {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.prompt-files {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.prompt-file {
  padding: 12px;
  margin-top: 0;
}

.prompt-file textarea {
  margin-top: 10px;
  min-height: 140px;
  background: #fff;
}

@media (max-width: 1180px) {
  body {
    overflow: auto;
  }

  .app-shell {
    grid-template-columns: 260px minmax(0, 1fr);
    height: auto;
    min-height: 100vh;
  }

  .settings-panel {
    grid-column: 1 / -1;
    overflow: visible;
  }
}

@media (max-width: 820px) {
  .app-shell {
    grid-template-columns: 1fr;
    padding: 10px;
  }

  .sidebar,
  .chat-panel,
  .settings-panel {
    min-height: auto;
  }

  .chat-panel {
    min-height: 70vh;
  }

  .chat-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .message-row {
    max-width: 86%;
  }

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