:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #f0f2f5;
  --border: #e2e5ea;
  --text: #1a1d21;
  --text-dim: #656d76;
  --accent: #1a56db;
  --accent-soft: #eef3fd;
  --danger: #b42318;
  --radius: 10px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181c;
    --surface: #1e2126;
    --surface-2: #262a30;
    --border: #31363d;
    --text: #e6e8eb;
    --text-dim: #9aa2ad;
    --accent: #5b8def;
    --accent-soft: #1f2937;
    --danger: #f97066;
  }
}

* { box-sizing: border-box; }

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", sans-serif;
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

/* ---------- ログイン ---------- */
.login-wrap {
  min-height: 100%;
  display: grid;
  place-items: center;
  padding: 24px;
}

.login-card {
  width: 100%;
  max-width: 380px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 32px 28px;
}

.login-card h1 {
  margin: 0 0 4px;
  font-size: 19px;
  letter-spacing: -0.01em;
}

.login-card .sub {
  margin: 0 0 24px;
  color: var(--text-dim);
  font-size: 13px;
}

/* ---------- 全体レイアウト ---------- */
.app {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.topbar .brand {
  font-weight: 650;
  letter-spacing: -0.01em;
}

.topbar .meta {
  color: var(--text-dim);
  font-size: 12px;
  margin-left: auto;
  text-align: right;
  line-height: 1.5;
}

.topbar button {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 5px 12px;
  border-radius: 7px;
  font-size: 12px;
  cursor: pointer;
}

.topbar button:hover { background: var(--surface-2); }

.main {
  flex: 1;
  overflow-y: auto;
}

.thread {
  max-width: 820px;
  margin: 0 auto;
  padding: 28px 20px 40px;
}

/* ---------- 空状態 ---------- */
.empty {
  padding: 40px 0 8px;
}

.empty h2 {
  font-size: 17px;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}

.empty p {
  color: var(--text-dim);
  margin: 0 0 24px;
  font-size: 14px;
}

.samples {
  display: grid;
  gap: 8px;
}

.samples button {
  text-align: left;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  font: inherit;
  font-size: 14px;
  color: var(--text);
  cursor: pointer;
  line-height: 1.5;
}

.samples button:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

/* ---------- メッセージ ---------- */
.msg { margin-bottom: 26px; }

.msg .role {
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  margin-bottom: 6px;
  text-transform: uppercase;
}

.msg.user .bubble {
  background: var(--accent-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
  white-space: pre-wrap;
}

.msg.bot .bubble > *:first-child { margin-top: 0; }
.msg.bot .bubble > *:last-child { margin-bottom: 0; }

/* ---------- 進捗 ---------- */
.steps {
  border-left: 2px solid var(--border);
  padding-left: 12px;
  margin-bottom: 14px;
  display: grid;
  gap: 3px;
}

.step {
  font-size: 12px;
  color: var(--text-dim);
  display: flex;
  gap: 8px;
  align-items: baseline;
}

.step .what { flex-shrink: 0; }

.step .detail {
  font-family: var(--mono);
  font-size: 11px;
  opacity: 0.85;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.thinking {
  display: inline-flex;
  gap: 4px;
  align-items: center;
  color: var(--text-dim);
  font-size: 13px;
}

.thinking .dot {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: currentColor;
  animation: pulse 1.2s infinite ease-in-out;
}
.thinking .dot:nth-child(2) { animation-delay: 0.15s; }
.thinking .dot:nth-child(3) { animation-delay: 0.3s; }

@keyframes pulse {
  0%, 80%, 100% { opacity: 0.25; }
  40% { opacity: 1; }
}

/* ---------- markdown ---------- */
.bubble h1, .bubble h2, .bubble h3 {
  letter-spacing: -0.01em;
  margin: 22px 0 8px;
  line-height: 1.4;
}
.bubble h1 { font-size: 18px; }
.bubble h2 { font-size: 16px; }
.bubble h3 { font-size: 14.5px; }

.bubble p { margin: 0 0 12px; }
.bubble ul, .bubble ol { margin: 0 0 12px; padding-left: 22px; }
.bubble li { margin-bottom: 4px; }

.bubble code {
  font-family: var(--mono);
  font-size: 12.5px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 5px;
}

.bubble pre {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  overflow-x: auto;
  margin: 0 0 12px;
}

.bubble pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 12.5px;
  line-height: 1.6;
}

.bubble blockquote {
  margin: 0 0 12px;
  padding: 10px 14px;
  border-left: 3px solid var(--accent);
  background: var(--surface);
  color: var(--text);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.bubble blockquote p:last-child { margin-bottom: 0; }

.table-scroll {
  overflow-x: auto;
  margin: 0 0 12px;
}

.bubble table {
  border-collapse: collapse;
  width: 100%;
  font-size: 13.5px;
}

.bubble th, .bubble td {
  border: 1px solid var(--border);
  padding: 7px 11px;
  text-align: left;
  vertical-align: top;
}

.bubble th {
  background: var(--surface-2);
  font-weight: 650;
}

.bubble a { color: var(--accent); }

.error-box {
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 14px;
}

/* ---------- 入力 ---------- */
.composer {
  flex-shrink: 0;
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 14px 20px 18px;
}

.composer-inner {
  max-width: 820px;
  margin: 0 auto;
}

.composer-row {
  display: flex;
  gap: 10px;
  align-items: flex-end;
}

textarea, input[type="password"] {
  width: 100%;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 11px 14px;
  resize: none;
}

textarea:focus, input[type="password"]:focus {
  outline: none;
  border-color: var(--accent);
}

textarea { max-height: 200px; line-height: 1.6; }

.btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 11px 20px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  flex-shrink: 0;
}

.btn:disabled { opacity: 0.45; cursor: default; }
.btn.block { width: 100%; }

.hint {
  color: var(--text-dim);
  font-size: 11.5px;
  margin-top: 8px;
}

.form-error {
  color: var(--danger);
  font-size: 13px;
  margin-top: 10px;
  min-height: 19px;
}

.banner {
  max-width: 820px;
  margin: 0 auto 18px;
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 13.5px;
}

@media (max-width: 640px) {
  .thread { padding: 20px 14px 32px; }
  .composer { padding: 10px 14px 14px; }
  .topbar { padding: 10px 14px; }
  .topbar .meta { display: none; }
}