/* ===== 艺用AI · Claude 风格设计系统 =====
 * 暖白纸感背景 · 黏土色(clay)点缀 · 衬线标题 + 无衬线正文 · 大量留白 · 极细边框
 */
:root {
  --bg: #f5f4ee;          /* 暖象牙白页面底 */
  --surface: #ffffff;     /* 卡片/对话面 */
  --surface-2: #faf9f5;   /* 次级面 */
  --ink: #2b2a27;         /* 暖近黑 */
  --ink-soft: #73726c;    /* 次要文字 */
  --ink-faint: #9b998f;   /* 弱化文字 */
  --line: #e7e4d9;        /* 极细边框 */
  --line-soft: #efece3;
  --clay: #cc785c;        /* 黏土色主点缀 */
  --clay-ink: #b35e42;    /* 悬停加深 */
  --clay-soft: #f3e9e2;   /* 黏土浅底 */
  --radius: 12px;
  --radius-lg: 16px;
  --font-serif: 'Georgia', 'Songti SC', 'Times New Roman', ui-serif, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
body { display: flex; flex-direction: column; min-height: 100vh; }

a { color: var(--clay-ink); text-decoration: none; }
a:hover { color: var(--clay); text-decoration: none; }

.container { width: 100%; max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ===== 顶部导航 ===== */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(245, 244, 238, 0.85);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 28px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand-logo { width: 24px; height: 24px; display: inline-flex; color: var(--clay); }
.brand-logo svg { width: 100%; height: 100%; }
.brand-name { font-family: var(--font-serif); font-weight: 600; font-size: 21px; letter-spacing: .2px; }
.brand .accent { color: var(--clay); }
.main-nav { display: flex; gap: 26px; margin-left: 6px; flex: 1; }
.main-nav a { color: var(--ink-soft); font-weight: 500; font-size: 15px; }
.main-nav a:hover, .main-nav a.active { color: var(--ink); }
.main-nav a.active { position: relative; }

.btn-settings {
  border: 1px solid var(--line); background: var(--surface); color: var(--ink-soft);
  padding: 7px 15px; border-radius: 9px; cursor: pointer; font-size: 14px; font-weight: 500;
  transition: border-color .15s, color .15s;
}
.btn-settings:hover { border-color: var(--clay); color: var(--clay-ink); }

/* ===== 对话页布局 ===== */
.chat-page { flex: 1; padding: 26px 0 36px; }
.chat-layout { display: grid; grid-template-columns: 252px 1fr; gap: 26px; align-items: start; }

/* 知识库侧栏 */
.kb-sidebar {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-lg); padding: 20px; position: sticky; top: 88px;
}
.kb-sidebar h3 { margin: 0 0 6px; font-size: 15px; font-family: var(--font-serif); font-weight: 600; }
.kb-hint { font-size: 12.5px; color: var(--ink-soft); margin: 0 0 14px; }
.kb-list { display: flex; flex-direction: column; gap: 7px; max-height: 44vh; overflow-y: auto; margin-bottom: 14px; }
.kb-item {
  background: var(--surface-2); border: 1px solid var(--line-soft); border-radius: 9px;
  padding: 9px 11px; font-size: 13px; color: var(--ink); font-weight: 500;
}
.kb-item small { display: block; font-weight: 400; color: var(--ink-soft); margin-top: 2px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* 对话主区 */
.chat-main {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-lg); display: flex; flex-direction: column; min-height: 72vh;
}
.chat-window { flex: 1; padding: 28px 30px; overflow-y: auto; max-height: 64vh; }
.msg { display: flex; gap: 14px; margin-bottom: 26px; }
.msg .avatar {
  width: 30px; height: 30px; border-radius: 7px; flex: 0 0 30px;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 700; font-family: var(--font-serif);
}
.msg-ai .avatar { background: var(--clay); color: #fff; }
.msg-user .avatar { background: var(--surface-2); border: 1px solid var(--line); color: var(--ink-soft); }
.msg-user { flex-direction: row-reverse; }

/* Claude 式：AI 回复无气泡，用户消息为柔和气泡 */
.bubble { max-width: 78%; line-height: 1.75; font-size: 15.5px; word-break: break-word; }
.msg-ai .bubble { padding-top: 3px; color: var(--ink); }
.msg-user .bubble {
  background: var(--surface-2); border: 1px solid var(--line);
  padding: 11px 16px; border-radius: 14px; color: var(--ink);
}
.bubble strong { font-weight: 600; }
.bubble pre { background: #2b2a27; color: #f3f1ea; padding: 14px; border-radius: 10px; overflow-x: auto; font-size: 13px; }
.bubble code { background: var(--surface-2); border: 1px solid var(--line); padding: 1px 5px; border-radius: 5px; font-size: 13.5px; }
.bubble pre code { background: none; border: none; padding: 0; color: inherit; }
.bubble h3, .bubble h4 { font-family: var(--font-serif); margin: 14px 0 6px; }
.bubble.thinking::after { content: '●'; color: var(--clay); animation: pulse 1.1s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: .25; } 50% { opacity: 1; } }

.chat-input-bar {
  display: flex; gap: 10px; padding: 16px 18px; border-top: 1px solid var(--line);
  align-items: flex-end;
}
#userInput {
  flex: 1; resize: none; border: 1px solid var(--line); border-radius: 13px;
  padding: 12px 15px; font-size: 15px; font-family: inherit; max-height: 150px;
  outline: none; background: var(--surface-2); color: var(--ink); transition: border-color .15s;
}
#userInput:focus { border-color: var(--clay); background: #fff; }
.btn-send {
  background: var(--clay); color: #fff; border: none; border-radius: 11px;
  padding: 0 22px; height: 44px; font-size: 15px; font-weight: 600; cursor: pointer;
  transition: background .15s;
}
.btn-send:hover { background: var(--clay-ink); }
.btn-send:disabled { opacity: .5; cursor: not-allowed; }
.chat-tip { text-align: center; color: var(--ink-faint); font-size: 12.5px; margin: 0 0 14px; }

/* ===== 通用按钮 ===== */
.btn-primary { background: var(--clay); color: #fff; border: none; padding: 10px 20px; border-radius: 10px; font-weight: 600; cursor: pointer; transition: background .15s; }
.btn-primary:hover { background: var(--clay-ink); }
.btn-secondary { background: var(--surface); border: 1px solid var(--line); color: var(--ink-soft); padding: 9px 16px; border-radius: 10px; font-weight: 500; cursor: pointer; width: 100%; transition: border-color .15s, color .15s; }
.btn-secondary:hover { border-color: var(--clay); color: var(--clay-ink); }

/* ===== 弹窗 ===== */
.modal-mask {
  position: fixed; inset: 0; background: rgba(43, 42, 39, 0.38);
  display: flex; align-items: center; justify-content: center; z-index: 100; padding: 20px;
}
.modal-mask[hidden] { display: none; }
.modal {
  background: var(--surface); border-radius: 18px; width: 100%; max-width: 460px;
  max-height: 88vh; overflow-y: auto; box-shadow: 0 24px 60px rgba(43, 42, 39, .18);
  border: 1px solid var(--line);
}
.modal-head { display: flex; justify-content: space-between; align-items: center; padding: 20px 24px; border-bottom: 1px solid var(--line); }
.modal-head h3 { margin: 0; font-size: 18px; font-family: var(--font-serif); font-weight: 600; }
.modal-close { border: none; background: none; font-size: 20px; line-height: 1; cursor: pointer; color: var(--ink-faint); }
.modal-close:hover { color: var(--ink); }
.modal-body { padding: 22px 24px; }
.modal-body label { display: block; font-weight: 500; font-size: 14px; margin: 16px 0 7px; }
.modal-body label:first-child { margin-top: 0; }
.modal-body input, .modal-body select, .modal-body textarea {
  width: 100%; border: 1px solid var(--line); border-radius: 10px; padding: 11px 13px;
  font-size: 14px; font-family: inherit; outline: none; background: var(--surface-2); color: var(--ink);
}
.modal-body input:focus, .modal-body select:focus, .modal-body textarea:focus { border-color: var(--clay); background: #fff; }
.form-hint { font-size: 12.5px; color: var(--ink-soft); margin: 8px 0 0; line-height: 1.6; }
.modal-body hr { border: none; border-top: 1px solid var(--line); margin: 20px 0; }
.modal-foot { display: flex; justify-content: flex-end; gap: 10px; padding: 16px 24px; border-top: 1px solid var(--line); }

.kb-manage-list { display: flex; flex-direction: column; gap: 8px; }
.kb-manage-item { display: flex; justify-content: space-between; align-items: center; gap: 10px; background: var(--surface-2); border: 1px solid var(--line-soft); border-radius: 10px; padding: 10px 13px; font-size: 13px; }
.kb-manage-item button { border: none; background: none; color: var(--clay-ink); cursor: pointer; font-size: 13px; }

/* ===== 页脚（标准 ICP 备案）===== */
.site-footer { background: var(--bg); border-top: 1px solid var(--line); padding: 22px 0; margin-top: auto; }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.footer-links { color: var(--ink-faint); font-size: 13.5px; }
.footer-links a { color: var(--ink-soft); margin: 0 9px; }
.footer-links a:hover { color: var(--clay-ink); }
.footer-links .sep { color: var(--line); }
.footer-beian { color: var(--ink-faint); font-size: 13px; }
.footer-beian a { color: var(--ink-faint); }
.footer-beian a:hover { color: var(--clay-ink); text-decoration: underline; }

/* ===== 内容页（关于 / 备案 / 知识库）===== */
.content-page { flex: 1; padding: 44px 0 56px; }
.content-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 44px 48px; max-width: 820px; margin: 0 auto;
}
.content-card h1 { margin-top: 0; font-size: 30px; font-family: var(--font-serif); font-weight: 600; letter-spacing: .2px; }
.content-card h2 { font-size: 19px; font-family: var(--font-serif); font-weight: 600; margin-top: 32px; color: var(--ink); }
.content-card p { color: #3f3e3a; }
.lead { color: var(--ink-soft); font-size: 16.5px; }
.info-table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14.5px; }
.info-table th, .info-table td { border-bottom: 1px solid var(--line); padding: 12px 6px; text-align: left; vertical-align: top; }
.info-table th { color: var(--ink-soft); font-weight: 500; width: 36%; }
.info-table td { color: var(--ink); }
.kb-page-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(248px, 1fr)); gap: 16px; margin-top: 24px; }
.kb-card { background: var(--surface-2); border: 1px solid var(--line); border-radius: 13px; padding: 20px; }
.kb-card h3 { margin: 0 0 8px; font-size: 16px; font-family: var(--font-serif); font-weight: 600; color: var(--ink); }
.kb-card p { margin: 0; font-size: 14px; color: var(--ink-soft); }

/* ===== 响应式 ===== */
@media (max-width: 860px) {
  .chat-layout { grid-template-columns: 1fr; }
  .kb-sidebar { position: static; order: 2; }
  .main-nav { display: none; }
  .bubble { max-width: 88%; }
  .content-card { padding: 26px 22px; }
  .content-card h1 { font-size: 25px; }
  .info-table th { width: 44%; }
}