/* Paper Library — 新设计系统（Stitch/Vercel 学术风）。
   自托管 Inter + Geist Mono（不依赖 Google Fonts，国内可用）；
   token 取自 Stitch DESIGN.md，全站复用。 */

@font-face { font-family: 'Inter'; font-style: normal; font-weight: 400;
  font-display: swap; src: url('fonts/inter-400.woff2') format('woff2'); }
@font-face { font-family: 'Inter'; font-style: normal; font-weight: 500;
  font-display: swap; src: url('fonts/inter-500.woff2') format('woff2'); }
@font-face { font-family: 'Inter'; font-style: normal; font-weight: 600;
  font-display: swap; src: url('fonts/inter-600.woff2') format('woff2'); }
@font-face { font-family: 'Inter'; font-style: normal; font-weight: 700;
  font-display: swap; src: url('fonts/inter-700.woff2') format('woff2'); }
@font-face { font-family: 'Geist Mono'; font-style: normal; font-weight: 400;
  font-display: swap; src: url('fonts/geist-mono-400.woff2') format('woff2'); }
@font-face { font-family: 'Geist Mono'; font-style: normal; font-weight: 500;
  font-display: swap; src: url('fonts/geist-mono-500.woff2') format('woff2'); }

:root {
  /* 表面 / 中性 */
  --bg: #f9f9f9;
  --panel: #ffffff;           /* canvas-white */
  --surface-low: #f3f3f3;
  --surface: #eeeeee;
  --surface-high: #e8e8e8;
  --ink: #1a1c1c;             /* on-surface / on-background */
  --ink-2: #4d4d4d;           /* body-secondary */
  --muted: #888888;           /* body-muted */
  --line: #ebebeb;            /* hairline */
  --line-strong: #c4c7c7;     /* outline-variant */
  --outline: #747878;

  /* 强调 */
  --primary: #000000;         /* 主色（黑，用于主按钮/logo） */
  --on-primary: #ffffff;
  --accent: #0057c0;          /* secondary（蓝，用于链接/选中/强调） */
  --accent-2: #006ff0;
  --accent-bg: #d3e5ff;       /* selection-bg */
  --accent-soft: #eaf1ff;

  /* 语义 */
  --ok: #0070f3;
  --warn: #f5a623;
  --error: #ee0000;
  --error-bg: #ffdad6;
  --highlight: #ffd88a;       /* 注释高亮 */
  --highlight-bg: #fffbeb;

  /* 渐变（登录顶部装饰条等） */
  --grad-a: #0070f3;
  --grad-b: #7928ca;
  --grad-c: #ff0080;

  /* 圆角 / 阴影 */
  --r-sm: 6px;
  --r-md: 8px;
  --r-lg: 12px;
  --r-xl: 16px;
  --shadow-card: 0 1px 2px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.04);
  --shadow-pop: 0 8px 30px -8px rgba(0,0,0,0.12), 0 2px 8px -2px rgba(0,0,0,0.06);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC',
          'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --mono: 'Geist Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body { background: var(--bg); color: var(--ink); font-family: var(--font);
  font-size: 14px; line-height: 1.55; -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.mono { font-family: var(--mono); }
.brand-mark { width: 26px; height: 26px; flex: none; vertical-align: middle; }

/* ============ 共享组件（类名沿用旧 collab.css，JS 无需改动） ============ */

/* 按钮 */
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 7px 13px;
  font: inherit; font-size: 13px; font-weight: 500; border-radius: var(--r-sm);
  cursor: pointer; border: 1px solid var(--line-strong); background: var(--panel);
  color: var(--ink); white-space: nowrap;
  transition: background .12s, border-color .12s, opacity .12s; }
.btn:hover { border-color: var(--ink); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.btn-primary:hover { background: #222; border-color: #222; opacity: 1; }
.btn-danger { color: var(--error); border-color: #f0c9c2; background: #fff5f4; }
.btn-danger:hover { background: var(--error); border-color: var(--error); color: #fff; }
.btn-ghost { border-color: transparent; background: transparent; color: var(--muted); }
.btn-ghost:hover { background: var(--surface-low); color: var(--ink); }
.btn-sm { padding: 3px 9px; font-size: 12px; border-radius: 5px; }

/* 表单 */
.input, .select, .textarea { font: inherit; font-size: 13px; padding: 8px 11px;
  border: 1px solid var(--line-strong); border-radius: var(--r-sm); background: #fbfbfb;
  color: var(--ink); width: 100%; transition: border-color .12s, box-shadow .12s; }
.input:focus, .select:focus, .textarea:focus { outline: none; border-color: var(--outline);
  background: #fff; box-shadow: 0 0 0 3px rgba(0,0,0,.04); }
.textarea { resize: vertical; min-height: 72px; line-height: 1.5; }
.field { margin-bottom: 12px; }
.field label { display: block; font-size: 12px; color: var(--ink-2); margin-bottom: 4px; }
.row2 { display: flex; gap: 12px; }
.row2 .field { flex: 1; }

/* Chips — 极简：默认中性，仅方向/本人工作/引用带强调 */
.chip { display: inline-flex; align-items: center; gap: 4px; border-radius: 6px;
  padding: 2px 8px; font-size: 11px; font-weight: 500; line-height: 1.6;
  border: 1px solid var(--line); background: var(--surface-low); color: var(--ink-2); }
.chip-dir    { background: var(--accent-soft); color: var(--accent); border-color: #cfe0fb; }
.chip-mywork { background: var(--primary); color: #fff; border-color: var(--primary); }
.chip-cite   { background: var(--surface-low); color: var(--ink); font-weight: 600; }
.chip-vis    { background: #fff7e8; color: #8a5a00; border-color: #f0e0c0; }
.tag { display: inline-block; background: var(--surface); color: var(--ink-2);
  border-radius: 5px; padding: 2px 8px; font-size: 11px; }

/* 头像（首字母色块，JS 会内联 background 覆盖颜色） */
.avatar { display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 50%; background: #9aa2ad; color: #fff;
  font-size: 13px; font-weight: 600; flex: none; user-select: none; }
.avatar-sm { width: 24px; height: 24px; font-size: 11px; }
.avatar-lg { width: 44px; height: 44px; font-size: 18px; }
.user-chip { display: inline-flex; align-items: center; gap: 8px; padding: 3px 10px 3px 3px;
  border: 1px solid var(--line-strong); border-radius: 20px; background: var(--panel);
  cursor: pointer; font: inherit; font-size: 13px; white-space: nowrap; }
.user-chip:hover { border-color: var(--ink); }

/* 弹窗 */
.modal-overlay { position: fixed; inset: 0; background: rgba(20,20,22,.4);
  display: flex; align-items: center; justify-content: center; z-index: 100;
  backdrop-filter: blur(2px); }
.modal { background: var(--panel); border-radius: var(--r-lg); min-width: 340px;
  max-width: min(560px, 92vw); max-height: 86vh; overflow-y: auto; box-shadow: var(--shadow-pop); }
.modal-head { padding: 15px 20px; border-bottom: 1px solid var(--line); font-weight: 600;
  font-size: 15px; display: flex; justify-content: space-between; align-items: center; }
.modal-head .x { cursor: pointer; color: var(--muted); border: none; background: none;
  font-size: 16px; padding: 2px 6px; }
.modal-body { padding: 16px 20px; }
.modal-actions { padding: 12px 20px 16px; display: flex; gap: 8px; justify-content: flex-end; }
.modal-danger-note { background: var(--error-bg); color: #93000a; border: 1px solid #f0c9c2;
  border-radius: var(--r-sm); padding: 8px 12px; font-size: 12px; margin-bottom: 12px; }
.note-box { border-radius: var(--r-sm); padding: 10px 12px; font-size: 12px;
  line-height: 1.6; margin: 12px 0; }
.note-sec { background: #fff8e6; color: #8a6a00; border: 1px solid #ffe5a8; }

/* Toast */
#toast-holder { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  z-index: 200; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.toast { background: var(--primary); color: #fff; padding: 9px 18px; border-radius: var(--r-md);
  font-size: 13px; box-shadow: var(--shadow-pop); animation: toast-in .18s ease-out; max-width: 80vw; }
.toast.err { background: var(--error); }
.toast.ok { background: var(--ok); }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

/* 评论 */
.comment { display: flex; gap: 10px; padding: 12px 0; }
.comment-main { flex: 1; min-width: 0; }
.comment-head { display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.comment-head .name { font-weight: 600; font-size: 13px; }
.comment-head .time { color: var(--muted); font-size: 11px; }
.comment-kind { font-size: 10px; padding: 1px 7px; border-radius: 6px; border: 1px solid var(--line);
  color: var(--muted); background: var(--surface-low); }
.kind-idea { color: var(--accent); } .kind-question { color: #9a6a00; }
.kind-note { color: var(--ok); } .kind-resource { color: #5b30b8; }
.comment-body { margin: 4px 0; white-space: pre-wrap; word-break: break-word; font-size: 13.5px; }
.comment-actions { display: flex; gap: 10px; }
.comment-actions button { border: none; background: none; color: var(--muted); font-size: 12px;
  cursor: pointer; padding: 0; }
.comment-actions button:hover { color: var(--accent); }
.comment-children { margin-left: 34px; border-left: 2px solid var(--line); padding-left: 12px; }
.composer { display: flex; gap: 10px; margin-top: 12px; }
.composer .textarea { min-height: 60px; }
.composer-foot { display: flex; gap: 8px; margin-top: 8px; align-items: center; justify-content: flex-end; }
.mention { color: var(--accent); font-weight: 600; background: var(--accent-soft);
  border-radius: 3px; padding: 0 3px; }

/* 注释卡 */
.anno { border: 1px solid var(--line); border-radius: var(--r-md); padding: 10px 12px;
  margin-bottom: 10px; background: var(--panel); }
.anno-head { display: flex; align-items: center; gap: 8px; margin-bottom: 4px; }
.anno-head .name { font-weight: 600; font-size: 12px; }
.anno-head .page-link { margin-left: auto; font-size: 11px; color: var(--accent); cursor: pointer; white-space: nowrap; }
.anno-quote { border-left: 3px solid var(--highlight); background: var(--highlight-bg);
  padding: 5px 10px; font-size: 12px; color: #6b5b2e; margin: 6px 0; border-radius: 0 4px 4px 0;
  word-break: break-word; }
.anno-content { font-size: 13px; white-space: pre-wrap; word-break: break-word; }
.anno-foot { display: flex; gap: 6px; margin-top: 6px; align-items: center; flex-wrap: wrap; }
.anno-foot .spacer { flex: 1; }
.page-link { cursor: pointer; }

/* 空 / 加载 / 错误 */
.empty-state { text-align: center; color: var(--muted); padding: 48px 20px; }
.empty-state .big { font-size: 28px; margin-bottom: 8px; }
.empty-state-inline { color: var(--muted); font-size: 13px; padding: 8px 0; }
.loading { text-align: center; color: var(--muted); padding: 28px; font-size: 13px; }
.loading::after { content: '…'; animation: dots 1.2s steps(4) infinite; }
@keyframes dots { 0% { content: ''; } 25% { content: '.'; } 50% { content: '..'; } 75% { content: '...'; } }
.error-banner { background: var(--error-bg); color: #93000a; border: 1px solid #f0c9c2;
  border-radius: var(--r-md); padding: 10px 14px; font-size: 13px; margin: 12px 0; }
.badge { display: inline-flex; align-items: center; gap: 3px; font-size: 11px; color: var(--muted); }
.badge b { font-weight: 600; color: var(--ink); }