/* ── Reset ─────────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --sidebar-bg: #1a1d2e;
  --sidebar-w: 260px;
  --topbar-h: 56px;
  --primary: #5b6af8;
  --primary-dk: #4a59e8;
  --primary-lt: #eef0ff;
  --bg: #f7f8fa;
  --white: #ffffff;
  --border: #e5e7eb;
  --text: #1a1d2e;
  --text-2: #6b7280;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
}

html, body { height: 100%; font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif; background: var(--bg); color: var(--text); }

/* ── Layout ────────────────────────────────────────────────────────────────── */
.app-layout { display: flex; height: 100vh; overflow: hidden; }

/* ── Sidebar ───────────────────────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w); background: var(--sidebar-bg);
  display: flex; flex-direction: column; flex-shrink: 0;
  transition: transform .2s; z-index: 200;
}
.sidebar-header { padding: 20px 16px 16px; border-bottom: 1px solid rgba(255,255,255,.08); }
.logo { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.logo-icon { font-size: 22px; }
.logo-text { font-size: 17px; font-weight: 700; color: #fff; }
.new-btn {
  width: 100%; padding: 9px 0; background: var(--primary); color: #fff;
  border: none; border-radius: var(--radius); font-size: 14px; font-weight: 600;
  cursor: pointer; transition: background .15s;
}
.new-btn:hover { background: var(--primary-dk); }

.sidebar-history { flex: 1; overflow-y: auto; padding: 12px 8px; }
.history-label { font-size: 11px; font-weight: 600; color: rgba(255,255,255,.3); text-transform: uppercase; letter-spacing: .08em; padding: 0 8px 8px; }
.history-empty { padding: 20px 8px; color: rgba(255,255,255,.3); font-size: 13px; text-align: center; }
.h-item {
  padding: 9px 10px; border-radius: var(--radius); cursor: pointer;
  color: rgba(255,255,255,.7); transition: background .12s;
  display: flex; align-items: flex-start; gap: 6px;
}
.h-item:hover { background: rgba(255,255,255,.07); }
.h-item.active { background: rgba(91,106,248,.35); color: #fff; }
.h-item-body { flex: 1; min-width: 0; }
.h-item-title { font-size: 13px; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.h-item-date { font-size: 11px; color: rgba(255,255,255,.3); margin-top: 2px; }
.h-del { background: none; border: none; color: rgba(255,255,255,.3); cursor: pointer; font-size: 14px; padding: 2px 4px; border-radius: 4px; flex-shrink: 0; display: none; }
.h-item:hover .h-del { display: block; }
.h-del:hover { background: rgba(255,0,0,.2); color: #ff6b6b; }

.sidebar-footer { padding: 14px 12px; border-top: 1px solid rgba(255,255,255,.08); }
.user-info { display: flex; align-items: center; gap: 10px; }
.user-avatar {
  width: 34px; height: 34px; border-radius: 50%; background: var(--primary);
  color: #fff; font-size: 14px; font-weight: 700;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.user-detail { flex: 1; min-width: 0; }
.user-name { font-size: 13px; font-weight: 600; color: #fff; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.user-email { font-size: 11px; color: rgba(255,255,255,.4); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.logout-btn { background: none; border: none; color: rgba(255,255,255,.4); cursor: pointer; font-size: 18px; padding: 4px; border-radius: 6px; transition: all .15s; flex-shrink: 0; }
.logout-btn:hover { background: rgba(255,255,255,.1); color: #fff; }

/* ── Main ──────────────────────────────────────────────────────────────────── */
.main { flex: 1; display: flex; flex-direction: column; overflow: hidden; min-width: 0; }

.topbar {
  height: var(--topbar-h); background: var(--white); border-bottom: 1px solid var(--border);
  display: flex; align-items: center; padding: 0 20px; gap: 12px; flex-shrink: 0;
  box-shadow: var(--shadow);
}
.menu-btn { background: none; border: none; font-size: 18px; cursor: pointer; color: var(--text-2); padding: 4px 8px; border-radius: 6px; display: none; }
.menu-btn:hover { background: var(--bg); }
.topbar-title { flex: 1; font-size: 15px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topbar-actions { display: flex; gap: 8px; flex-shrink: 0; }
.export-btn {
  padding: 7px 14px; background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius); font-size: 13px; font-weight: 500; cursor: pointer;
  color: var(--text); transition: all .15s;
}
.export-btn:hover { background: var(--primary-lt); border-color: var(--primary); color: var(--primary); }
.bundle-btn { background: var(--primary); color: #fff; border-color: var(--primary); font-weight: 600; }
.bundle-btn:hover { background: var(--primary-dk); border-color: var(--primary-dk); color: #fff; }

/* ── Content ───────────────────────────────────────────────────────────────── */
.content { flex: 1; overflow: hidden; position: relative; }

/* ── Chat View ─────────────────────────────────────────────────────────────── */
.chat-view { height: 100%; display: flex; flex-direction: column; }

/* Welcome */
.welcome {
  flex: 1; display: flex; flex-direction: column; align-items: center;
  justify-content: center; padding: 40px 24px; text-align: center; gap: 16px;
}
.welcome-icon { font-size: 56px; }
.welcome h2 { font-size: 26px; font-weight: 800; }
.welcome p { color: var(--text-2); font-size: 15px; max-width: 480px; line-height: 1.6; }
.feature-tags { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.feature-tags span {
  padding: 6px 14px; background: var(--white); border: 1px solid var(--border);
  border-radius: 20px; font-size: 13px; color: var(--text-2); box-shadow: var(--shadow);
}
.examples { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.examples-label { font-size: 13px; color: var(--text-2); font-weight: 500; }
.example-list { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.example-btn {
  padding: 8px 16px; background: var(--white); border: 1px solid var(--primary);
  border-radius: var(--radius); font-size: 13px; color: var(--primary);
  cursor: pointer; font-weight: 500; transition: all .15s;
}
.example-btn:hover { background: var(--primary); color: #fff; }

/* Messages */
.messages { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 16px; }
.msg { display: flex; gap: 12px; max-width: 82%; }
.msg.user { align-self: flex-end; flex-direction: row-reverse; }
.msg.assistant { align-self: flex-start; }
.msg-avatar {
  width: 32px; height: 32px; border-radius: 50%; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: 15px;
}
.msg.user .msg-avatar { background: var(--primary); color: #fff; font-size: 11px; font-weight: 700; }
.msg.assistant .msg-avatar { background: var(--bg); border: 1px solid var(--border); }
.msg-bubble {
  padding: 11px 15px; border-radius: var(--radius-lg);
  font-size: 14px; line-height: 1.6; max-width: 100%;
}
.msg.user .msg-bubble { background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.msg.assistant .msg-bubble { background: var(--white); border: 1px solid var(--border); border-bottom-left-radius: 4px; box-shadow: var(--shadow); }

/* Clarification bubble */
.clarify-bubble {
  background: #fffbeb; border: 1px solid #fcd34d; border-radius: var(--radius-lg);
  padding: 14px 16px; font-size: 14px; line-height: 1.6;
}
.clarify-bubble .q-list { margin-top: 10px; display: flex; flex-direction: column; gap: 6px; }
.clarify-bubble .q-item {
  padding: 8px 12px; background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius); color: var(--text); font-size: 13px;
}

/* PRD done bubble */
.prd-done-bubble {
  background: var(--primary-lt); border: 1px solid var(--primary);
  border-radius: var(--radius-lg); padding: 14px 16px; font-size: 14px;
}
.view-prd-btn {
  padding: 8px 20px; background: var(--primary); color: #fff;
  border: none; border-radius: var(--radius); cursor: pointer;
  font-size: 14px; font-weight: 600; transition: background .15s;
}
.view-prd-btn:hover { background: var(--primary-dk); }
.feishu-link {
  color: #2b6de5; font-weight: 600; text-decoration: none; font-size: 14px;
}
.feishu-link:hover { text-decoration: underline; }
.feishu-status { font-size: 14px; }

/* Streaming cursor */
.cursor { display: inline-block; width: 2px; height: 14px; background: var(--primary); animation: blink .7s infinite; vertical-align: text-bottom; }
@keyframes blink { 0%,100% { opacity:1; } 50% { opacity:0; } }

/* Progress bar */
.progress {
  padding: 12px 20px; background: var(--white); border-top: 1px solid var(--border);
  display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--text-2);
}
.spinner { animation: spin 1.2s linear infinite; display: inline-block; }
@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* Input area */
.input-area { background: var(--white); border-top: 1px solid var(--border); padding: 12px 20px 16px; }
.input-toolbar { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.attach-btn { font-size: 18px; cursor: pointer; padding: 4px 6px; border-radius: 6px; transition: background .12s; }
.attach-btn:hover { background: var(--bg); }
.file-tag { font-size: 12px; color: var(--text-2); }
.input-row { display: flex; gap: 10px; align-items: flex-end; }
textarea {
  flex: 1; padding: 10px 14px; border: 1.5px solid var(--border);
  border-radius: var(--radius-lg); font-size: 14px; font-family: inherit;
  resize: none; outline: none; transition: border-color .15s;
  line-height: 1.5; max-height: 160px; overflow-y: auto;
}
textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(91,106,248,.1); }
.send-btn {
  padding: 10px 20px; background: var(--primary); color: #fff; border: none;
  border-radius: var(--radius-lg); font-size: 14px; font-weight: 600;
  cursor: pointer; transition: background .15s; height: 42px; white-space: nowrap;
}
.send-btn:hover:not(:disabled) { background: var(--primary-dk); }
.send-btn:disabled { background: #a5b4fc; cursor: not-allowed; }

/* ── PRD View ──────────────────────────────────────────────────────────────── */
.prd-view { height: 100%; display: flex; flex-direction: column; background: var(--white); }
.prd-toolbar {
  padding: 12px 20px; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 12px; flex-shrink: 0;
}
.back-btn {
  padding: 6px 14px; background: none; border: 1px solid var(--border);
  border-radius: var(--radius); font-size: 13px; cursor: pointer;
  color: var(--text-2); transition: all .15s;
}
.back-btn:hover { background: var(--bg); color: var(--text); }
.prd-tabs { display: flex; gap: 4px; }
.ptab {
  padding: 6px 16px; background: none; border: 1px solid transparent;
  border-radius: var(--radius); font-size: 13px; cursor: pointer;
  color: var(--text-2); transition: all .15s;
}
.ptab.active { background: var(--primary-lt); border-color: var(--primary); color: var(--primary); font-weight: 600; }
.ptab:hover:not(.active) { background: var(--bg); }
.prd-body { flex: 1; overflow: hidden; }
.prd-preview { height: 100%; overflow-y: auto; padding: 36px 56px; max-width: 920px; margin: 0 auto; width: 100%; }
.prd-source { height: 100%; overflow-y: auto; padding: 20px; background: #f8f9fa; }
.prd-source pre { font-size: 13px; line-height: 1.6; white-space: pre-wrap; word-break: break-word; }

/* ── PRD Markdown Styles ───────────────────────────────────────────────────── */
.prd-preview h1 { font-size: 28px; font-weight: 800; padding-bottom: 12px; border-bottom: 2px solid var(--primary); margin: 0 0 24px; }
.prd-preview h2 { font-size: 20px; font-weight: 700; padding-bottom: 8px; border-bottom: 1px solid var(--border); margin: 32px 0 14px; }
.prd-preview h3 { font-size: 16px; font-weight: 700; margin: 22px 0 10px; }
.prd-preview h4 { font-size: 14px; font-weight: 600; color: var(--text-2); margin: 16px 0 8px; }
.prd-preview p { font-size: 14px; line-height: 1.75; color: #374151; margin: 0 0 12px; }
.prd-preview ul, .prd-preview ol { margin: 8px 0 16px 20px; }
.prd-preview li { font-size: 14px; line-height: 1.65; color: #374151; margin: 5px 0; }
.prd-preview strong { font-weight: 700; color: var(--text); }
.prd-preview em { font-style: italic; }
.prd-preview code { background: #f1f5f9; padding: 2px 6px; border-radius: 4px; font-size: 13px; font-family: 'SF Mono','Fira Code',monospace; color: #e11d48; }
.prd-preview pre { background: #1e293b; border-radius: var(--radius-lg); padding: 20px; overflow-x: auto; margin: 16px 0; }
.prd-preview pre code { background: none; padding: 0; color: #e2e8f0; font-size: 13px; }
.prd-preview blockquote { margin: 16px 0; padding: 12px 16px; border-left: 4px solid var(--primary); background: var(--primary-lt); border-radius: 0 var(--radius) var(--radius) 0; }
.prd-preview blockquote p { color: var(--primary-dk); margin: 0; }
.prd-preview hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }
.prd-preview table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 13px; }
.prd-preview th { background: #f1f5f9; padding: 10px 14px; text-align: left; font-weight: 600; border: 1px solid var(--border); }
.prd-preview td { padding: 10px 14px; border: 1px solid var(--border); color: #374151; line-height: 1.5; }
.prd-preview tr:nth-child(even) td { background: #fafafa; }
.prd-preview .mermaid { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 20px; margin: 16px 0; text-align: center; overflow-x: auto; }
.wireframe-wrap { border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; margin: 16px 0; }
.wireframe-label { padding: 10px 14px; background: #f1f5f9; font-size: 13px; color: var(--text-2); border-bottom: 1px solid var(--border); font-weight: 600; }
.wireframe-wrap iframe { width: 100%; border: none; min-height: 400px; display: block; }
.wireframe-actions { display: flex; gap: 8px; padding: 12px 14px; background: #fff; border-bottom: 1px solid var(--border); flex-wrap: wrap; }
.wireframe-btn { display: inline-flex; align-items: center; gap: 4px; padding: 6px 14px; border-radius: 6px; font-size: 13px; cursor: pointer; border: 1px solid var(--border); background: #fff; color: var(--text-1); text-decoration: none; transition: all .15s; }
.wireframe-btn:hover { background: var(--primary-lt); border-color: var(--primary); color: var(--primary); }
.wireframe-btn.download-btn { background: var(--primary); color: #fff; border-color: var(--primary); }
.wireframe-btn.download-btn:hover { background: var(--primary-dk); }
.wireframe-preview-area { padding: 0; }

/* ── Scrollbar ─────────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #d1d5db; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #9ca3af; }

/* ── Responsive ────────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .sidebar { position: fixed; height: 100%; transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); box-shadow: 4px 0 20px rgba(0,0,0,.3); }
  .menu-btn { display: flex !important; }
  .prd-preview { padding: 20px 16px; }
  .msg { max-width: 96%; }
}