/* ============================================================
   阅渡 · 学生 PDF 阅读批注台
   纸感底 + 黛青主色；阅读优先，工具不抢内容
   ============================================================ */

:root {
  --paper: #f6f4ef;
  --paper-2: #efece4;
  --surface: #ffffff;
  --surface-2: #fbfaf7;
  --ink: #1e2226;
  --ink-2: #464c52;
  --muted: #7c8288;
  --line: #e6e2d9;
  --line-strong: #d6d1c5;
  --primary: #2a6f6a;
  --primary-ink: #1f5b57;
  --primary-tint: #e7f0ee;
  --danger: #bf4a41;
  --stage: #e9e6de;
  --shadow-1: 0 1px 2px rgba(31, 34, 38, .05), 0 6px 18px rgba(31, 34, 38, .06);
  --shadow-2: 0 10px 34px rgba(31, 34, 38, .12);
  --shadow-page: 0 1px 3px rgba(30, 30, 28, .16), 0 12px 26px rgba(30, 30, 28, .10);
  --r-sm: 8px;
  --r: 12px;
  --r-lg: 18px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, serif;
  color-scheme: light;
}

body[data-theme="dark"] {
  --paper: #14171a;
  --paper-2: #101315;
  --surface: #1b1f23;
  --surface-2: #1f2429;
  --ink: #e7e9ea;
  --ink-2: #c2c7cb;
  --muted: #8d959b;
  --line: #2b3136;
  --line-strong: #3a4147;
  --primary: #63b6ab;
  --primary-ink: #8fcfc6;
  --primary-tint: #1d2b2a;
  --danger: #e0665c;
  --stage: #0e1113;
  --shadow-1: 0 1px 2px rgba(0, 0, 0, .3), 0 6px 18px rgba(0, 0, 0, .25);
  --shadow-2: 0 10px 34px rgba(0, 0, 0, .45);
  --shadow-page: 0 1px 3px rgba(0, 0, 0, .5), 0 12px 26px rgba(0, 0, 0, .35);
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow: hidden;
}
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
svg { width: 20px; height: 20px; display: block; }
button { font: inherit; color: inherit; }
input { font: inherit; color: inherit; }

/* ---------- 通用控件 ---------- */
.icon-btn {
  width: 36px; height: 36px; flex: 0 0 auto;
  display: grid; place-items: center;
  border: 1px solid transparent; border-radius: 10px;
  background: transparent; color: var(--ink-2);
  cursor: pointer; transition: background .15s, color .15s, border-color .15s;
}
.icon-btn:hover { background: var(--paper-2); color: var(--ink); }
.icon-btn:active { transform: translateY(.5px); }
.icon-btn:disabled { opacity: .32; cursor: default; background: transparent; }
.icon-btn svg { width: 19px; height: 19px; }
.icon-btn.sm { width: 30px; height: 30px; }
.icon-btn.sm svg { width: 17px; height: 17px; }

.btn {
  display: inline-flex; align-items: center; gap: 6px;
  height: 38px; padding: 0 16px;
  border-radius: 10px; border: 1px solid var(--line-strong);
  background: var(--surface); color: var(--ink);
  cursor: pointer; white-space: nowrap;
  transition: background .15s, border-color .15s, box-shadow .15s, transform .1s;
}
.btn:hover { border-color: var(--primary); color: var(--primary-ink); }
.btn:active { transform: translateY(.5px); }
.btn svg { width: 17px; height: 17px; }
.btn-sm { height: 32px; padding: 0 12px; font-size: 13px; border-radius: 9px; }
.btn-primary { background: var(--primary); border-color: var(--primary); color: #fff; box-shadow: 0 2px 6px rgba(42, 111, 106, .22); }
.btn-primary:hover { background: var(--primary-ink); border-color: var(--primary-ink); color: #fff; }
.btn-ghost { background: transparent; border-color: var(--line); }
.btn-ghost:hover { background: var(--paper-2); }
.btn-danger { background: var(--danger); border-color: var(--danger); color: #fff; }
.btn-danger:hover { filter: brightness(.94); color: #fff; }

.link-btn {
  border: 0; background: none; padding: 0; cursor: pointer;
  color: var(--primary-ink); font-weight: 600;
  border-bottom: 1px solid color-mix(in srgb, var(--primary) 45%, transparent);
}
.link-btn:hover { border-bottom-color: var(--primary); }

:focus-visible { outline: 2px solid color-mix(in srgb, var(--primary) 60%, transparent); outline-offset: 2px; }

/* ---------- 屏幕切换 ---------- */
.screen { position: fixed; inset: 0; display: none; }
.screen.is-active { display: flex; flex-direction: column; }

/* ============================================================
   资料库
   ============================================================ */
.lib-wrap {
  flex: 1; display: flex; flex-direction: column;
  width: 100%; max-width: 1140px; margin: 0 auto;
  padding: 0 28px; min-height: 0;
}
.lib-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 0 18px; flex: 0 0 auto;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 42px; height: 42px; border-radius: 13px;
  display: grid; place-items: center;
  background: var(--primary); color: #fff;
  box-shadow: 0 3px 10px rgba(42, 111, 106, .26);
}
.brand-mark svg { width: 23px; height: 23px; }
.brand-txt h1 {
  margin: 0; font-family: var(--serif);
  font-size: 21px; font-weight: 700; letter-spacing: .04em; line-height: 1.2;
}
.brand-txt p { margin: 2px 0 0; font-size: 12.5px; color: var(--muted); letter-spacing: .02em; }

.head-right { display: flex; align-items: center; gap: 8px; }
.chip {
  display: inline-flex; align-items: center; gap: 7px;
  height: 36px; padding: 0 12px;
  border-radius: 999px; border: 1px solid var(--line);
  background: var(--surface); cursor: pointer;
  font-size: 12.5px; color: var(--ink-2);
  transition: border-color .15s, background .15s;
}
.chip:hover { border-color: var(--primary); background: var(--surface-2); }
.chip .dot { width: 7px; height: 7px; border-radius: 50%; background: #b9b3a7; }
.chip .dot.on { background: #3f9c67; box-shadow: 0 0 0 3px rgba(63, 156, 103, .16); }
.chip .dot.off { background: #c9814a; }
.chip .dot.sync { background: #c9a227; animation: pulse 1.1s infinite; }
.chip b { font-weight: 600; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px; color: var(--ink); }
@keyframes pulse { 50% { opacity: .35; } }

.lib-body { flex: 1; min-height: 0; overflow-y: auto; padding-bottom: 26px; scrollbar-gutter: stable; }

.drop-zone {
  border: 1.5px dashed var(--line-strong); border-radius: var(--r-lg);
  background: var(--surface-2);
  padding: 22px 24px; text-align: center;
  transition: border-color .18s, background .18s;
}
.drop-zone.dragover { border-color: var(--primary); background: var(--primary-tint); }
.drop-ico {
  width: 38px; height: 38px; margin: 0 auto 8px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--primary-tint); color: var(--primary);
}
.drop-ico svg { width: 20px; height: 20px; }
.drop-title { margin: 0; font-size: 14.5px; color: var(--ink); }
.drop-sub { margin: 6px 0 0; font-size: 12.5px; color: var(--muted); }
.drop-acts { margin-top: 12px; display: flex; justify-content: center; gap: 8px; }

.lib-bar {
  display: flex; align-items: baseline; justify-content: space-between;
  margin: 26px 2px 12px;
}
.lib-bar h2 { margin: 0; font-size: 14px; font-weight: 600; letter-spacing: .02em; }
.lib-bar h2 em { font-style: normal; color: var(--muted); font-weight: 500; margin-left: 4px; }
.sync-hint { font-size: 12px; color: var(--muted); }
.sync-hint.err { color: var(--danger); }

.doc-grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fill, minmax(168px, 1fr));
}
.doc-card {
  position: relative; border: 1px solid transparent; border-radius: var(--r);
  background: var(--surface); box-shadow: var(--shadow-1);
  cursor: pointer; overflow: hidden;
  transition: transform .18s, box-shadow .18s, border-color .18s;
  display: flex; flex-direction: column;
}
.doc-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-2); border-color: color-mix(in srgb, var(--primary) 30%, var(--line)); }
.doc-thumb {
  position: relative; aspect-ratio: 3 / 4; background: var(--paper-2);
  display: grid; place-items: center; overflow: hidden;
}
.doc-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.doc-thumb .ph { color: var(--line-strong); }
.doc-thumb .ph svg { width: 34px; height: 34px; }
.doc-thumb .badge {
  position: absolute; left: 8px; top: 8px;
  height: 22px; padding: 0 8px; border-radius: 999px;
  display: inline-flex; align-items: center; gap: 4px;
  background: rgba(24, 28, 30, .58); backdrop-filter: blur(6px);
  color: #fff; font-size: 11px; font-weight: 600;
}
.doc-thumb .badge svg { width: 12px; height: 12px; }
.doc-info { padding: 10px 11px 12px; min-width: 0; }
.doc-name {
  margin: 0; font-size: 13px; font-weight: 600; line-height: 1.45; color: var(--ink);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
  word-break: break-word;
}
.doc-sub { margin: 5px 0 0; font-size: 11.5px; color: var(--muted); display: flex; gap: 8px; }
.doc-menu-btn {
  position: absolute; right: 7px; top: 7px; width: 26px; height: 26px;
  border-radius: 8px; border: 0; background: rgba(255, 255, 255, .86);
  color: var(--ink-2); display: grid; place-items: center; cursor: pointer;
  opacity: 0; transition: opacity .15s;
}
.doc-card:hover .doc-menu-btn, .doc-menu-btn:focus-visible { opacity: 1; }
.doc-menu-btn svg { width: 15px; height: 15px; }

.empty { text-align: center; padding: 40px 16px 10px; display: none; }
.empty.show { display: block; }
.empty-ico { width: 56px; height: 56px; margin: 0 auto 14px; border-radius: 16px; display: grid; place-items: center; background: var(--primary-tint); color: var(--primary); }
.empty-ico svg { width: 28px; height: 28px; }
.empty h3 { margin: 0 0 6px; font-family: var(--serif); font-size: 17px; }
.empty p { margin: 0 0 16px; color: var(--muted); font-size: 13px; }

.lib-foot {
  flex: 0 0 auto; display: flex; justify-content: space-between;
  padding: 12px 2px 16px; border-top: 1px solid var(--line);
  color: var(--muted); font-size: 11.5px;
}

/* ============================================================
   阅读器
   ============================================================ */
#screen-reader { background: var(--paper); }
.rd-head {
  flex: 0 0 auto; height: 56px;
  display: flex; align-items: center; gap: 10px;
  padding: 0 12px 0 8px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  position: relative; z-index: 30;
}
.rd-left { display: flex; align-items: center; gap: 4px; min-width: 0; flex: 1 1 auto; }
.rd-title { min-width: 0; margin-left: 2px; }
.rd-title h2 {
  margin: 0; font-size: 13.5px; font-weight: 600;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 34vw;
}
.rd-title p { margin: 0; font-size: 11.5px; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.rd-mid { display: flex; align-items: center; gap: 4px; flex: 0 0 auto; }
.page-box {
  display: inline-flex; align-items: center; gap: 3px;
  height: 30px; padding: 0 8px; border-radius: 9px;
  background: var(--paper-2); font-size: 12.5px; color: var(--ink-2);
}
.page-box input {
  width: 34px; height: 22px; text-align: center;
  border: 1px solid transparent; border-radius: 6px;
  background: var(--surface); font-size: 12.5px; font-variant-numeric: tabular-nums;
}
.page-box input:focus { border-color: var(--primary); outline: none; }
.page-box b { font-weight: 600; color: var(--muted); }
.rd-right { display: flex; align-items: center; gap: 2px; flex: 1 1 auto; justify-content: flex-end; }
.sep { width: 1px; height: 20px; background: var(--line); margin: 0 4px; }
.zoom-btn {
  height: 28px; min-width: 48px; padding: 0 6px;
  border: 1px solid transparent; border-radius: 8px; background: transparent;
  font-size: 12px; color: var(--ink-2); cursor: pointer; font-variant-numeric: tabular-nums;
}
.zoom-btn:hover { background: var(--paper-2); color: var(--ink); }
.save-state {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 11.5px; color: var(--muted); padding: 0 4px; white-space: nowrap;
}
.save-state i { width: 6px; height: 6px; border-radius: 50%; background: var(--primary); }
.save-state.saving i { background: #c9a227; animation: pulse 1s infinite; }
.save-state.offline i { background: var(--danger); }
.save-state em { font-style: normal; }

.menu {
  position: absolute; right: 10px; top: 52px; z-index: 60;
  min-width: 190px; padding: 6px;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 12px; box-shadow: var(--shadow-2);
}
.menu button {
  display: flex; align-items: center; gap: 9px; width: 100%;
  height: 34px; padding: 0 10px; border: 0; border-radius: 8px;
  background: transparent; cursor: pointer; font-size: 13px; color: var(--ink-2); text-align: left;
}
.menu button:hover { background: var(--paper-2); color: var(--ink); }
.menu button svg { width: 16px; height: 16px; }
.menu button.danger { color: var(--danger); }
.menu button.danger:hover { background: color-mix(in srgb, var(--danger) 10%, transparent); }

.rd-body { flex: 1; display: flex; min-height: 0; position: relative; }

.thumb-rail {
  flex: 0 0 auto; width: 0; overflow: hidden;
  background: var(--surface-2); border-right: 1px solid var(--line);
  transition: width .2s ease;
}
.thumb-rail.open { width: 104px; }
.thumb-list { width: 104px; padding: 10px 0; height: 100%; overflow-y: auto; }
.thumb-item {
  width: 84px; margin: 0 auto 10px; cursor: pointer;
  border-radius: 6px; border: 1.5px solid transparent; overflow: hidden;
  background: #fff; box-shadow: 0 1px 3px rgba(0, 0, 0, .12);
  position: relative;
}
.thumb-item canvas, .thumb-item .tph { display: block; width: 81px; background: #fff; }
.thumb-item .tph { height: 105px; }
.thumb-item.is-cur { border-color: var(--primary); }
.thumb-item span {
  position: absolute; right: 3px; bottom: 3px;
  font-size: 9.5px; color: #fff; background: rgba(0, 0, 0, .5);
  padding: 0 4px; border-radius: 4px; line-height: 15px;
}

.stage {
  flex: 1; min-width: 0; overflow: auto; position: relative;
  background: var(--stage);
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}
.pages {
  display: flex; flex-direction: column; align-items: center;
  gap: 18px; padding: 22px 16px 120px;
  min-height: 100%;
}
.pg {
  position: relative; flex: 0 0 auto;
  background: #fff; border-radius: 3px;
  box-shadow: var(--shadow-page);
  overflow: hidden;
}
.pg canvas { display: block; position: absolute; inset: 0; width: 100%; height: 100%; }
.pg .cv-ink { touch-action: none; }
.pg.is-loading::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, #f4f2ec 30%, #fbf9f4 50%, #f4f2ec 70%);
  background-size: 220% 100%; animation: shimmer 1.3s infinite linear;
}
@keyframes shimmer { to { background-position: -120% 0; } }
#live-canvas { position: absolute; pointer-events: none; z-index: 5; }

.stage-empty { position: absolute; inset: 0; display: grid; place-items: center; color: var(--muted); }

/* ---------- 工具坞 ---------- */
.dock {
  position: absolute; left: 50%; bottom: 22px; transform: translateX(-50%);
  z-index: 40; display: flex; align-items: center; gap: 4px;
  padding: 7px 9px;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(14px) saturate(1.2);
  border: 1px solid var(--line);
  border-radius: 999px;
  box-shadow: var(--shadow-2);
  max-width: calc(100vw - 24px);
}
.dock-group { display: flex; align-items: center; gap: 3px; }
.tool {
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid transparent; background: transparent;
  display: grid; place-items: center; cursor: pointer; color: var(--ink-2);
  transition: background .15s, color .15s, transform .12s;
}
.tool svg { width: 20px; height: 20px; }
.tool:hover { background: var(--paper-2); color: var(--ink); }
.tool.is-on {
  background: var(--primary-tint); color: var(--primary-ink);
  border-color: color-mix(in srgb, var(--primary) 32%, transparent);
}
.dock-sep { width: 1px; height: 24px; background: var(--line); margin: 0 3px; flex: 0 0 auto; }
.color {
  width: 24px; height: 24px; border-radius: 50%;
  border: 2px solid var(--surface); cursor: pointer;
  box-shadow: 0 0 0 1px var(--line);
  transition: transform .12s, box-shadow .12s;
  padding: 0;
}
.color:hover { transform: scale(1.1); }
.color.is-on { box-shadow: 0 0 0 2px var(--primary); transform: scale(1.08); }
.width {
  width: 32px; height: 30px; border-radius: 8px;
  border: 1px solid transparent; background: transparent;
  display: grid; place-items: center; cursor: pointer; padding: 0;
}
.width i { display: block; width: 16px; border-radius: 3px; background: var(--ink-2); }
.width:hover { background: var(--paper-2); }
.width.is-on { background: var(--primary-tint); border-color: color-mix(in srgb, var(--primary) 30%, transparent); }
.width.is-on i { background: var(--primary-ink); }
.dock.hide-colors .colors, .dock.hide-colors .dock-sep.w-colors, .dock.hide-colors .widths, .dock.hide-colors .dock-sep.w-widths { display: none; }

/* ---------- 提示 / 加载 ---------- */
.toast {
  position: fixed; left: 50%; bottom: 92px; transform: translate(-50%, 12px);
  background: rgba(28, 32, 34, .92); color: #fff;
  padding: 9px 16px; border-radius: 10px; font-size: 13px;
  opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s;
  z-index: 200; max-width: min(86vw, 480px); text-align: center;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast.err { background: rgba(150, 52, 46, .95); }

.loading { position: fixed; inset: 0; background: rgba(20, 23, 25, .34); backdrop-filter: blur(3px); display: grid; place-items: center; z-index: 300; }
.loading-card {
  width: min(320px, 84vw); padding: 22px 22px 18px;
  background: var(--surface); border-radius: var(--r-lg); box-shadow: var(--shadow-2);
  text-align: center;
}
.loading-card p { margin: 12px 0 14px; font-size: 13px; color: var(--ink-2); }
.spinner {
  width: 26px; height: 26px; margin: 0 auto; border-radius: 50%;
  border: 2.5px solid var(--primary-tint); border-top-color: var(--primary);
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.bar { height: 4px; border-radius: 2px; background: var(--paper-2); overflow: hidden; }
.bar i { display: block; height: 100%; width: 0; background: var(--primary); transition: width .25s; }

/* ---------- 弹窗 ---------- */
.modal {
  position: fixed; inset: 0; z-index: 400;
  display: grid; place-items: center;
  background: rgba(24, 27, 29, .38); backdrop-filter: blur(3px);
  padding: 20px;
}
.modal[hidden] { display: none; }
.modal-card {
  position: relative; width: min(460px, 100%);
  background: var(--surface); border-radius: var(--r-lg);
  padding: 24px; box-shadow: var(--shadow-2);
  animation: pop .18s ease-out;
}
@keyframes pop { from { opacity: 0; transform: translateY(8px) scale(.98); } }
.modal-card h3 { margin: 0 0 6px; font-family: var(--serif); font-size: 17px; }
.modal-sub { margin: 0 0 16px; font-size: 12.8px; color: var(--muted); line-height: 1.65; }
.modal-x { position: absolute; right: 10px; top: 10px; width: 30px; height: 30px; border-radius: 8px; border: 0; background: transparent; color: var(--muted); cursor: pointer; display: grid; place-items: center; }
.modal-x:hover { background: var(--paper-2); color: var(--ink); }
.field { display: block; }
.field span { display: block; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.field input {
  width: 100%; height: 42px; padding: 0 12px;
  border: 1px solid var(--line-strong); border-radius: 10px;
  background: var(--surface-2); font-size: 14px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}
.field input:focus { border-color: var(--primary); background: var(--surface); outline: none; box-shadow: 0 0 0 3px var(--primary-tint); }
.field-err { min-height: 18px; margin: 6px 0 0; font-size: 12px; color: var(--danger); }
.modal-acts { display: flex; gap: 8px; justify-content: flex-end; margin-top: 8px; flex-wrap: wrap; }
.modal-note { margin: 14px 0 0; font-size: 11.5px; color: var(--muted); line-height: 1.6; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 860px) {
  .lib-wrap { padding: 0 16px; }
  .lib-head { padding: 16px 0 12px; }
  .brand-txt p { display: none; }
  .chip .chip-label { display: none; }
  .doc-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 12px; }
  .drop-zone { padding: 18px 14px; }
  .drop-sub { font-size: 12px; }
  .only-wide { display: none !important; }
  .rd-head { height: 52px; padding-right: 8px; }
  .rd-title h2 { max-width: 30vw; font-size: 13px; }
  .rd-title p { display: none; }
  .rd-mid { gap: 0; }
  .save-state em { display: none; }
  .pages { padding: 12px 8px 108px; gap: 12px; }
  .dock { bottom: calc(10px + env(safe-area-inset-bottom)); padding: 6px 7px; gap: 2px; }
  .tool { width: 38px; height: 38px; }
  .color { width: 22px; height: 22px; }
  .width { width: 26px; }
  .doc-menu-btn { opacity: 1; }
}
@media (max-width: 560px) {
  .lib-foot { font-size: 10.5px; }
  .lib-foot span:last-child { display: none; }
  .rd-right .icon-btn.sm, .rd-right .sep { display: none; }
  .rd-left { flex: 0 1 auto; min-width: 0; }
  .rd-title h2 { max-width: 26vw; }
  .rd-mid { flex: 0 0 auto; }
  .rd-right { flex: 0 0 auto; gap: 0; }
  .rd-right .save-state { display: none; }
  .zoom-btn { min-width: 42px; }
  .dock { gap: 0; padding: 6px; }
  .tool { width: 34px; height: 34px; }
  .tool svg { width: 18px; height: 18px; }
  .color { width: 20px; height: 20px; }
  .width { width: 26px; }
  .width i { width: 13px; }
  .modal-card { padding: 20px 18px; }
  .btn { height: 36px; padding: 0 13px; }
}

@media print {
  .rd-head, .dock, .thumb-rail, .toast { display: none !important; }
}