/* ============================================================
 * Cloudflare Pages LLM Chat — 样式 (css/style.css)
 * 功能：A2 深浅主题 / A6 移动端 / Markdown / 消息 / 登录 / 弹窗
 * ============================================================ */

/* ---------- 1. 主题变量（A2：浅色为默认，dark 覆盖变量） ---------- */
:root {
  --bg: #f6f7f9;            /* 页面背景 */
  --panel: #ffffff;         /* 面板/卡片 */
  --bubble-user: #3b6ff0;   /* 用户气泡 */
  --bubble-user-text: #fff;
  --bubble-bot: #eef0f3;    /* 机器人气泡 */
  --text: #1f2328;
  --text-sub: #6b7280;
  --border: #e2e5ea;
  --accent: #3b6ff0;
  --danger: #d33;
  --shadow: 0 2px 10px rgba(0,0,0,.06);
  --code-bg: #f3f4f6;
}

body.dark {
  --bg: #0f1115;
  --panel: #171a21;
  --bubble-user: #4c7cff;
  --bubble-user-text: #fff;
  --bubble-bot: #232731;
  --text: #e6e8ec;
  --text-sub: #9aa0ab;
  --border: #2a2f3a;
  --accent: #4c7cff;
  --danger: #f87171;
  --shadow: 0 2px 10px rgba(0,0,0,.4);
  --code-bg: #1d212a;
}

/* ---------- 2. 基础重置 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background .25s, color .25s;
}
button { cursor: pointer; font: inherit; border: none; background: none; color: inherit; }
.hidden { display: none !important; }
.error { color: var(--danger); }

/* ---------- 3. 登录层 (C1) ---------- */
.overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(0,0,0,.45);
  display: flex; align-items: center; justify-content: center;
}
.login-card, .modal-card {
  background: var(--panel);
  border-radius: 12px;
  padding: 28px;
  width: min(92vw, 360px);
  box-shadow: var(--shadow);
  text-align: center;
}
.login-card h2 { font-size: 1.2rem; margin-bottom: 6px; }
.login-hint { font-size: .82rem; color: var(--text-sub); margin-bottom: 16px; }
.login-card input {
  width: 100%; padding: 10px; margin-bottom: 12px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--panel); color: var(--text);
}
.login-card button {
  width: 100%; padding: 10px; border-radius: 8px;
  background: var(--accent); color: #fff; font-weight: 600;
}
#loginError { margin-top: 10px; font-size: .85rem; }

/* ---------- 4. 主布局：侧栏 + 主区 ---------- */
#app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

#sidebar {
  width: 260px; flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
}
.side-head { padding: 12px; border-bottom: 1px solid var(--border); }
.side-head .primary {
  width: 100%; padding: 10px; border-radius: 8px;
  background: var(--accent); color: #fff; font-weight: 600;
}
.session-list { flex: 1; overflow-y: auto; padding: 8px; }
.session-item {
  padding: 10px 12px; margin-bottom: 6px; border-radius: 8px;
  cursor: pointer; transition: background .15s;
}
.session-item:hover { background: rgba(128,128,128,.12); }
.session-item.active { background: var(--accent); color: #fff; }
.session-item .s-title { display: block; font-weight: 600; font-size: .92rem;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.session-item .s-meta { font-size: .76rem; opacity: .75; }
.side-foot { padding: 10px; border-top: 1px solid var(--border); display: flex; gap: 8px; }
.side-foot button {
  flex: 1; padding: 9px; border-radius: 8px;
  background: rgba(128,128,128,.12); font-size: .85rem;
}
.side-foot button:hover { background: rgba(128,128,128,.22); }

/* ---------- 5. 主聊天区 ---------- */
#main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

#toolbar {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}
#toolbar select {
  padding: 7px 10px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--panel); color: var(--text);
}
#toolbar button {
  padding: 7px 12px; border-radius: 8px;
  background: rgba(128,128,128,.12); font-size: .88rem;
}
#toolbar button:hover { background: rgba(128,128,128,.22); }
#btnLogout { margin-left: auto; }

#chat {
  flex: 1; overflow-y: auto;
  padding: 20px 16px;
}

/* ---------- 6. 消息气泡 (A2 / A8) ---------- */
.msg { margin-bottom: 16px; max-width: 78%; }
.msg.user { margin-left: auto; text-align: right; }
.msg.bot  { margin-right: auto; text-align: left; }

.bubble {
  display: inline-block; text-align: left;
  padding: 10px 14px; border-radius: 12px;
  line-height: 1.65; font-size: .95rem;
  white-space: pre-wrap; word-break: break-word;
}
.msg.user .bubble {
  background: var(--bubble-user); color: var(--bubble-user-text);
  border-bottom-right-radius: 4px;
}
.msg.bot .bubble {
  background: var(--bubble-bot); color: var(--text);
  border-bottom-left-radius: 4px;
}

.copy {
  display: inline-block; margin-top: 4px;
  font-size: .78rem; color: var(--text-sub);
  padding: 3px 8px; border-radius: 6px;
}
.copy:hover { background: rgba(128,128,128,.15); color: var(--text); }

/* ---------- 7. Markdown 渲染样式 (A2) ---------- */
.bubble.md { white-space: normal; }
.bubble.md h1, .bubble.md h2, .bubble.md h3, .bubble.md h4 {
  margin: 10px 0 6px; line-height: 1.3;
}
.bubble.md h1 { font-size: 1.35rem; }
.bubble.md h2 { font-size: 1.2rem; }
.bubble.md h3 { font-size: 1.08rem; }
.bubble.md p { margin: 6px 0; }
.bubble.md ul, .bubble.md ol { padding-left: 20px; margin: 6px 0; }
.bubble.md li { margin: 3px 0; }
.bubble.md strong { font-weight: 700; }
.bubble.md em { font-style: italic; }
.bubble.md blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 10px; margin: 8px 0; color: var(--text-sub);
}
.bubble.md code {
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  background: var(--code-bg); padding: 2px 5px; border-radius: 4px; font-size: .85em;
}
.bubble.md pre {
  background: var(--code-bg); padding: 12px; border-radius: 8px;
  overflow-x: auto; margin: 8px 0;
}
.bubble.md pre code { background: none; padding: 0; }
.bubble.md table { border-collapse: collapse; margin: 8px 0; }
.bubble.md th, .bubble.md td {
  border: 1px solid var(--border); padding: 6px 10px;
}
.bubble.md a { color: var(--accent); }

/* ---------- 8. 输入栏 ---------- */
.inputbar {
  display: flex; gap: 8px; align-items: flex-end;
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}
#input {
  flex: 1; resize: none;
  padding: 10px 12px; min-height: 42px; max-height: 160px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--panel); color: var(--text);
  font: inherit; line-height: 1.5;
}
#input:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
#btnSend {
  padding: 10px 18px; border-radius: 10px;
  background: var(--accent); color: #fff; font-weight: 600;
}
#btnSend:disabled { opacity: .5; cursor: not-allowed; }

/* ---------- 9. 用量统计弹窗 (D2) ---------- */
.modal-card { width: min(92vw, 420px); text-align: left; }
.modal-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 14px; }
.modal-head h3 { font-size: 1.05rem; }
.modal-head button { font-size: 1.1rem; color: var(--text-sub); }
#statsBody p { margin: 6px 0; }
#statsBody ul { padding-left: 20px; margin: 6px 0; }
#statsBody li { margin: 3px 0; }

/* ============================================================
 * A6 移动端适配（< 768px：侧栏变抽屉，聊天区全屏）
 * ============================================================ */
@media (max-width: 768px) {
  #app { flex-direction: column; }

  /* 侧栏变成顶部横条 + 可横向滑动的会话列表 */
  #sidebar {
    width: 100%; height: auto;
    border-right: none; border-bottom: 1px solid var(--border);
    flex-direction: row; align-items: center;
  }
  .side-head { border-bottom: none; padding: 8px 10px; }
  .side-head .primary { width: auto; padding: 8px 12px; font-size: .88rem; }
  .session-list {
    flex: 1; display: flex; gap: 6px; padding: 6px;
    overflow-x: auto; white-space: nowrap;
  }
  .session-item { min-width: 120px; margin-bottom: 0; font-size: .85rem; }
  .session-item .s-meta { display: none; }
  .side-foot { border-top: none; padding: 8px; }
  .side-foot button { font-size: .8rem; padding: 7px; }

  /* 消息宽度放宽 */
  .msg { max-width: 90%; }
  #chat { padding: 14px 10px; }
  #toolbar { padding: 8px 10px; flex-wrap: wrap; }
  .inputbar { padding: 10px; }
  #btnSend { padding: 10px 14px; }
}

/* 超窄屏时隐藏导出/统计文字，只留图标 */
@media (max-width: 480px) {
  .side-foot button { font-size: .74rem; }
}