/* ══════════════════════════════════════════════════════════════════
   Linux 学习打卡平台 · 主题层
   浅色 = 纸张手绘白  |  深色 = 深蓝科技（正文全部使用白色文字）
   手绘感来源：feTurbulence 位移滤镜描边 + 不规则圆角 + 手写体字栈
   ══════════════════════════════════════════════════════════════════ */

/* ───────── 1. 设计令牌 ───────── */
:root {
  /* 字体：手写体优先，逐级兜底（Windows 楷体 / macOS 手札体 / iOS / Android） */
  --font-hand: "KaiTi", "STKaiti", "楷体", "Kaiti SC", "Hanzipen SC", "Wawati SC",
               "STXingkai", "Xingkai SC", "LiSu", "隶书", "Yuanti SC",
               "Comic Sans MS", "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-ui: var(--font-hand);
  --font-mono: ui-monospace, "Cascadia Mono", Consolas, "SFMono-Regular", Menlo, monospace;
  --font-num: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;

  --r-card: 255px 18px 225px 16px / 16px 225px 18px 255px;
  --r-btn: 225px 14px 255px 14px / 14px 255px 14px 225px;
  --r-input: 16px 220px 18px 225px / 220px 16px 225px 18px;
  --r-chip: 200px 12px 180px 12px / 12px 180px 12px 200px;

  --sp: 8px;
  --top-h: 62px;
  --side-w: 272px;

  /* ── 实心填充专用令牌 ──
     --accent 用于「深色背景上的浅色文字/描边」（浅色主题下即墨蓝，深色主题下提亮为亮蓝）；
     --accent-solid 用于「按钮/头像等实心色块」，两种主题下都保证与白字达到可读对比度。 */
  --accent-solid: var(--accent);
  --accent-solid-2: var(--accent-2);
  --accent-solid-ink: #ffffff;
  --ok-solid: #2f7d4f;
  --warn-solid: #a8641a;
  --danger-solid: #b3392f;
  --purple-solid: #6a4a9c;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --t-fast: .16s var(--ease);
  --t: .26s var(--ease);
  --t-slow: .42s var(--ease);
}

/* ═══════════ 浅色主题：纸张手绘 ═══════════ */
html[data-theme="light"] {
  color-scheme: light;

  --paper: #fdfbf5;
  --paper-2: #f6f2e8;
  --surface: #fffdf8;
  --surface-2: #f7f3e9;
  --surface-3: #efe9da;

  --ink: #1f2430;            /* 主文字：墨黑 */
  --ink-2: #4a5364;
  --ink-3: #7d879b;

  --stroke: #2b3445;         /* 手绘描边 */
  --stroke-2: #9aa4b8;
  --stroke-soft: rgba(43, 52, 69, .16);

  --accent: #2b5d8f;         /* 主色：墨蓝 */
  --accent-2: #3d7cb8;
  --accent-ink: #ffffff;
  --accent-soft: rgba(43, 93, 143, .12);

  --ok: #2f7d4f;
  --ok-soft: rgba(47, 125, 79, .14);
  --warn: #a8641a;
  --warn-soft: rgba(168, 100, 26, .14);
  --danger: #b3392f;
  --danger-soft: rgba(179, 57, 47, .13);
  --purple: #6a4a9c;

  --mark: #ffe9a8;           /* 荧光笔 */
  --mark-2: #cfe9ff;

  --shadow: 3px 4px 0 var(--stroke-soft);
  --shadow-lg: 5px 7px 0 var(--stroke-soft);
  --shadow-press: 1px 1px 0 var(--stroke-soft);

  --code-bg: #22272f;
  --code-ink: #e8eef7;
  --grid: rgba(43, 52, 69, .045);
}

/* ═══════════ 深色主题：深蓝科技（文字全部为白色） ═══════════ */
html[data-theme="dark"] {
  color-scheme: dark;

  --paper: #050e21;
  --paper-2: #071127;
  --surface: #0b1a35;
  --surface-2: #0e2040;
  --surface-3: #142a4f;

  --ink: #ffffff;                      /* 正文纯白 */
  --ink-2: rgba(255, 255, 255, .88);
  --ink-3: rgba(255, 255, 255, .66);

  --stroke: rgba(255, 255, 255, .82);  /* 手绘白描边 */
  --stroke-2: rgba(255, 255, 255, .5);
  --stroke-soft: rgba(255, 255, 255, .22);

  --accent: #56b6ff;
  --accent-2: #7fd0ff;
  --accent-ink: #04223c;
  --accent-soft: rgba(86, 182, 255, .18);

  --ok: #5ee79a;
  --ok-soft: rgba(94, 231, 154, .16);
  --warn: #ffcb5c;
  --warn-soft: rgba(255, 203, 92, .16);
  --danger: #ff8080;
  --danger-soft: rgba(255, 128, 128, .16);
  --purple: #c0a6ff;

  --mark: rgba(255, 203, 92, .3);
  --mark-2: rgba(86, 182, 255, .28);

  --shadow: 3px 4px 0 rgba(255, 255, 255, .18);
  --shadow-lg: 5px 7px 0 rgba(255, 255, 255, .14);
  --shadow-press: 1px 1px 0 rgba(255, 255, 255, .18);

  --code-bg: #04101f;
  --code-ink: #d8ecff;
  --grid: rgba(255, 255, 255, .035);

  /* 深色主题：实心色块压深，白字对比度 ≥ 4.5:1 */
  --accent-solid: #1668c9;
  --accent-solid-2: #2c7fe0;
  --accent-solid-ink: #ffffff;
  --ok-solid: #1c8550;
  --warn-solid: #9a5c14;
  --danger-solid: #c03434;
  --purple-solid: #6d4fbe;
}

/* ───────── 2. 基础重置 ───────── */
*, *::before, *::after { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.78;
  color: var(--ink);
  background: var(--paper);
  letter-spacing: .012em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background var(--t), color var(--t);
}

/* 纸张纹理 + 淡淡的方格（手绘信纸感） */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 26px 26px, 26px 26px;
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 82%);
          mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 82%);
}
/* 深色下的科技辉光 */
html[data-theme="dark"] body::after {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background:
    radial-gradient(900px 520px at 8% -10%, rgba(33, 106, 214, .28), transparent 62%),
    radial-gradient(760px 480px at 100% 0%, rgba(56, 182, 255, .16), transparent 60%),
    radial-gradient(820px 620px at 50% 112%, rgba(88, 110, 255, .16), transparent 62%);
}
html[data-theme="light"] body::after {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background:
    radial-gradient(820px 480px at 6% -8%, rgba(184, 214, 245, .55), transparent 66%),
    radial-gradient(700px 460px at 100% 4%, rgba(255, 236, 196, .5), transparent 62%);
}

.svg-defs { position: absolute; width: 0; height: 0; overflow: hidden; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline wavy var(--accent-2) 1px; }
button { font-family: inherit; }
img { max-width: 100%; }

::selection { background: var(--mark); color: var(--ink); }
html[data-theme="dark"] ::selection { background: rgba(86, 182, 255, .45); color: #fff; }

:focus-visible {
  outline: 2.5px dashed var(--accent);
  outline-offset: 3px;
}

/* 滚动条 */
::-webkit-scrollbar { width: 11px; height: 11px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--stroke-soft);
  border-radius: 8px;
  border: 3px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background: var(--stroke-2); background-clip: padding-box; }

/* 手写体下的数字/代码用无衬线，避免笔画粘连 */
.num, .mono, code, kbd, pre, input[type="date"] { font-variant-numeric: tabular-nums; }

/* ───────── 3. 手绘基础件 ───────── */

/* 手绘描边卡片：用伪元素 + 位移滤镜画出抖动的边框，文字保持清晰 */
.sketch { position: relative; }
.sketch > .sketch-border,
.sketch::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-card);
  filter: url(#rough);
  pointer-events: none;
  z-index: 0;
}

.card {
  position: relative;
  background: var(--surface);
  border-radius: var(--r-card);
  padding: 18px 20px;
  box-shadow: var(--shadow);
  transition: transform var(--t), box-shadow var(--t);
}
.card::before {
  content: "";
  position: absolute; inset: 0;
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-card);
  filter: url(#rough);
  pointer-events: none;
}
.card > * { position: relative; z-index: 1; }
.card.hoverable:hover { transform: translate(-2px, -2px); box-shadow: var(--shadow-lg); }

/* 手绘分隔线 */
.hr {
  height: 0; border: 0; margin: 18px 0;
  border-top: 2px dashed var(--stroke-soft);
}

/* 手写标题下划线 */
.uline { position: relative; display: inline-block; }
.uline::after {
  content: "";
  position: absolute; left: -2px; right: -2px; bottom: -6px; height: 8px;
  background: var(--mark);
  border-radius: 40% 60% 55% 45% / 60% 40% 60% 40%;
  z-index: -1;
  transform: rotate(-.6deg);
}
html[data-theme="dark"] .uline::after { opacity: .55; }

/* ───────── 4. 按钮 ───────── */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 9px 18px;
  font-family: var(--font-ui);
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: .03em;
  color: var(--ink);
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-btn);
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform var(--t-fast), box-shadow var(--t-fast), background var(--t-fast), color var(--t-fast);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}
.btn:hover { transform: translate(-2px, -2px); box-shadow: var(--shadow-lg); background: var(--surface-2); }
.btn:active { transform: translate(2px, 2px); box-shadow: var(--shadow-press); }
.btn[disabled], .btn.disabled { opacity: .45; pointer-events: none; }

.btn-primary { background: var(--accent-solid); color: var(--accent-solid-ink); }
.btn-primary:hover { background: var(--accent-solid-2); }

.btn-ok { background: var(--ok-solid); color: #fff; }
.btn-danger { background: var(--danger-solid); color: #fff; }
.btn-ghost { background: transparent; }
.btn-sm { padding: 5px 12px; font-size: 14px; border-width: 2px; }
.btn-lg { padding: 13px 26px; font-size: 17.5px; }
.btn-block { width: 100%; }

/* 图标按钮 */
.icon-btn {
  width: 40px; height: 40px;
  display: grid; place-items: center;
  font-size: 17px;
  color: var(--ink);
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: 50% 46% 52% 48% / 48% 52% 46% 52%;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform var(--t-fast), box-shadow var(--t-fast), background var(--t-fast);
  -webkit-tap-highlight-color: transparent;
}
.icon-btn:hover { transform: translate(-2px, -2px) rotate(-4deg); box-shadow: var(--shadow-lg); }
.icon-btn:active { transform: translate(2px, 2px) rotate(3deg); box-shadow: var(--shadow-press); }

/* 手绘小圆点按钮 */
.dot-btn {
  width: 34px; height: 34px; display: grid; place-items: center;
  font-size: 15px; background: var(--surface); color: var(--ink);
  border: 2px solid var(--stroke); border-radius: 50%;
  cursor: pointer; transition: var(--t-fast);
}
.dot-btn:hover { background: var(--accent-soft); transform: scale(1.08) rotate(-5deg); }

/* ───────── 5. 表单 ───────── */
.input, .select, .textarea {
  width: 100%;
  padding: 10px 14px;
  font-family: var(--font-ui);
  font-size: 16px;
  color: var(--ink);
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-input);
  outline: none;
  transition: box-shadow var(--t-fast), border-color var(--t-fast), background var(--t-fast);
  box-shadow: var(--shadow);
  -webkit-appearance: none;
  appearance: none;
}
.input::placeholder, .textarea::placeholder { color: var(--ink-3); }
.input:focus, .select:focus, .textarea:focus {
  border-color: var(--accent);
  box-shadow: 3px 4px 0 var(--accent-soft), 0 0 0 3px var(--accent-soft);
}
.textarea { min-height: 96px; resize: vertical; line-height: 1.7; }
.select {
  background-image: linear-gradient(45deg, transparent 50%, var(--stroke) 50%),
                    linear-gradient(135deg, var(--stroke) 50%, transparent 50%);
  background-position: calc(100% - 19px) 50%, calc(100% - 13px) 50%;
  background-size: 6px 6px, 6px 6px;
  background-repeat: no-repeat;
  padding-right: 38px;
  cursor: pointer;
}
html[data-theme="dark"] .select option { background: var(--surface); color: var(--ink); }

.field { display: block; margin-bottom: 14px; }
.field-label {
  display: block;
  font-size: 14.5px; font-weight: 700; color: var(--ink-2);
  margin-bottom: 5px; letter-spacing: .05em;
}
.field-hint { font-size: 13px; color: var(--ink-3); margin-top: 5px; line-height: 1.6; }

.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* 手绘复选框 */
input[type="checkbox"].ck, .checkline input[type="checkbox"] {
  -webkit-appearance: none; appearance: none;
  width: 21px; height: 21px; flex: 0 0 21px;
  margin: 0; position: relative; cursor: pointer;
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: 30% 58% 34% 60% / 58% 32% 60% 36%;
  transition: background var(--t-fast), transform var(--t-fast), border-color var(--t-fast);
  -webkit-tap-highlight-color: transparent;
}
input[type="checkbox"].ck:hover, .checkline input[type="checkbox"]:hover { transform: rotate(-8deg) scale(1.08); }
input[type="checkbox"].ck:active, .checkline input[type="checkbox"]:active { transform: scale(.9); }
input[type="checkbox"].ck:checked, .checkline input[type="checkbox"]:checked {
  background: var(--accent-solid);
  border-color: var(--accent-solid);
}
input[type="checkbox"].ck:checked::after, .checkline input[type="checkbox"]:checked::after {
  content: "";
  position: absolute; left: 5px; top: 1.5px;
  width: 5px; height: 11px;
  border: solid var(--accent-solid-ink);
  border-width: 0 2.8px 2.8px 0;
  transform: rotate(41deg);
  border-radius: 1px;
}
.checkline {
  display: inline-flex; align-items: center; gap: 8px;
  cursor: pointer; font-size: 15px; color: var(--ink-2);
  user-select: none;
}

/* 单选/多选组（手绘胶囊） */
.pick { display: inline-flex; gap: 8px; flex-wrap: wrap; }
.pick-opt {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 6px 14px; font-size: 15px; cursor: pointer;
  background: var(--surface); color: var(--ink-2);
  border: 2.5px solid var(--stroke-2);
  border-radius: var(--r-chip);
  transition: var(--t-fast);
}
.pick-opt:hover { border-color: var(--stroke); transform: translate(-1px, -1px); }
.pick-opt input { display: none; }
.pick-opt.on { background: var(--accent-soft); border-color: var(--accent); color: var(--ink); font-weight: 700; }

/* ───────── 6. 徽标 / 标签 ───────── */
.chip {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 12px;
  font-size: 14px; line-height: 1.7;
  color: var(--ink-2);
  background: var(--surface-2);
  border: 2px solid var(--stroke-soft);
  border-radius: var(--r-chip);
  white-space: nowrap;
}
.chip b { color: var(--ink); font-weight: 800; }
.chip.d1 { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.chip.d2 { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }
.chip.d3 { background: var(--warn-soft); border-color: var(--warn); color: var(--warn); }
.chip.d4 { background: var(--danger-soft); border-color: var(--danger); color: var(--danger); }
html[data-theme="dark"] .chip.d1 { color: var(--ok); }
html[data-theme="dark"] .chip.d2 { color: var(--accent-2); }

.badge {
  display: inline-grid; place-items: center;
  min-width: 20px; height: 20px; padding: 0 6px;
  font-size: 12.5px; font-weight: 800; font-family: var(--font-num);
  color: #fff; background: var(--danger-solid);
  border-radius: 40% 60% 45% 55% / 55% 45% 60% 40%;
}

.tag-done { color: var(--ok); font-weight: 700; }
.tag-todo { color: var(--ink-3); }

/* ───────── 7. 主题切换按钮 ───────── */
.theme-fab {
  position: relative;
  width: 44px; height: 44px; flex: 0 0 44px;
  display: grid; place-items: center;
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: 52% 48% 50% 50% / 48% 52% 48% 52%;
  box-shadow: var(--shadow);
  cursor: pointer;
  overflow: hidden;
  transition: transform var(--t), box-shadow var(--t), background var(--t);
  -webkit-tap-highlight-color: transparent;
}
.theme-fab:hover { transform: translate(-2px, -2px) rotate(12deg); box-shadow: var(--shadow-lg); }
.theme-fab:active { transform: translate(2px, 2px) rotate(-8deg); box-shadow: var(--shadow-press); }
.theme-ico { position: relative; width: 22px; height: 22px; display: block; }
.theme-ico::before {
  content: "";
  position: absolute; inset: 0;
  border-radius: 50%;
  background: #ffd666;
  box-shadow: 0 0 0 2.5px var(--stroke), inset -6px -6px 0 0 rgba(0, 0, 0, .06);
  transition: transform var(--t-slow), background var(--t), box-shadow var(--t);
  transform: scale(1);
}
.theme-ico::after {
  content: "";
  position: absolute; top: -4px; left: 6px;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--surface);
  transform: translate(16px, -12px) scale(0);
  transition: transform var(--t-slow);
}
html[data-theme="dark"] .theme-ico::before { background: #cfe4ff; }
html[data-theme="dark"] .theme-ico::after { transform: translate(2px, -5px) scale(1); }
.theme-fab.inline { width: 40px; height: 40px; flex-basis: 40px; }

/* 主题切换时的整体过渡（短暂加 class） */
html.theme-anim, html.theme-anim *, html.theme-anim *::before, html.theme-anim *::after {
  transition: background-color .42s var(--ease), color .42s var(--ease),
              border-color .42s var(--ease), box-shadow .42s var(--ease) !important;
}

/* ───────── 8. Toast ───────── */
.toasts {
  position: fixed; z-index: 200;
  right: 18px; bottom: 18px;
  display: flex; flex-direction: column-reverse; gap: 10px;
  pointer-events: none;
  max-width: min(360px, calc(100vw - 32px));
}
.toast {
  pointer-events: auto;
  display: flex; gap: 10px; align-items: flex-start;
  padding: 12px 16px;
  background: var(--surface);
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-card);
  box-shadow: var(--shadow-lg);
  animation: toastIn .34s var(--ease) both;
}
.toast.out { animation: toastOut .26s var(--ease) forwards; }
@keyframes toastIn { from { opacity: 0; transform: translateY(14px) rotate(-1.2deg) scale(.96); } to { opacity: 1; transform: none; } }
@keyframes toastOut { to { opacity: 0; transform: translateY(10px) scale(.96); } }
.toast .t-ico { font-size: 19px; line-height: 1.35; flex: 0 0 auto; }
.toast .t-body { min-width: 0; }
.toast .t-title { font-size: 15.5px; font-weight: 800; }
.toast .t-msg { font-size: 14px; color: var(--ink-2); line-height: 1.62; word-break: break-word; }
.toast.ok { border-color: var(--ok); }
.toast.err { border-color: var(--danger); }
.toast.warn { border-color: var(--warn); }

/* ───────── 9. 模态 ───────── */
.modal { position: fixed; inset: 0; z-index: 150; display: grid; place-items: center; padding: 18px; }
.modal[hidden] { display: none; }
.modal-bg { position: absolute; inset: 0; background: rgba(20, 26, 38, .55); backdrop-filter: blur(3px); animation: fade .22s; }
html[data-theme="dark"] .modal-bg { background: rgba(2, 7, 18, .72); }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

.modal-box {
  position: relative;
  width: 100%; max-width: 760px; max-height: 88vh;
  display: flex; flex-direction: column;
  background: var(--surface);
  border-radius: var(--r-card);
  box-shadow: 8px 10px 0 var(--stroke-soft);
  animation: popIn .3s var(--ease) both;
}
.modal-box::before {
  content: ""; position: absolute; inset: 0;
  border: 2.5px solid var(--stroke);
  border-radius: var(--r-card);
  filter: url(#rough);
  pointer-events: none;
}
@keyframes popIn { from { opacity: 0; transform: translateY(18px) rotate(.8deg) scale(.97); } to { opacity: 1; transform: none; } }
.modal-box.wide { max-width: 1040px; }
.modal-head {
  display: flex; align-items: center; gap: 12px;
  padding: 16px 20px; border-bottom: 2px dashed var(--stroke-soft);
  position: relative; z-index: 1;
}
.modal-head h3 { margin: 0; flex: 1; font-size: 19px; letter-spacing: .03em; }
/* min-height:0 让 .modal-body 在 flex 容器内真正可滚动；
   否则内容过长会把 .modal-box 撑破 max-height，底部按钮看不见 */
.modal-body { padding: 18px 20px; overflow-y: auto; min-height: 0; position: relative; z-index: 1; -webkit-overflow-scrolling: touch; }
.modal-foot {
  padding: 14px 20px; border-top: 2px dashed var(--stroke-soft);
  display: flex; gap: 10px; justify-content: flex-end; flex-wrap: wrap;
  position: relative; z-index: 1;
}
.modal-foot:empty { display: none; }

/* ───────── 10. 加载 / 空态 ───────── */
.loading { display: grid; place-items: center; padding: 52px 20px; gap: 14px; color: var(--ink-3); }
.spinner {
  width: 38px; height: 38px;
  border: 3.5px solid var(--stroke-soft);
  border-top-color: var(--accent);
  border-radius: 46% 54% 52% 48% / 52% 48% 54% 46%;
  animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.empty { text-align: center; padding: 52px 22px; color: var(--ink-3); }
.empty .e-ico { font-size: 44px; display: block; margin-bottom: 12px; opacity: .75; }
.empty .e-title { font-size: 17.5px; font-weight: 800; color: var(--ink-2); margin-bottom: 6px; }
.empty .e-sub { font-size: 14.5px; line-height: 1.75; }

/* 手绘骨架屏 */
.skeleton {
  background: linear-gradient(90deg, var(--surface-3) 25%, var(--surface-2) 37%, var(--surface-3) 63%);
  background-size: 400% 100%;
  animation: shimmer 1.4s ease-in-out infinite;
  border-radius: 8px;
}
@keyframes shimmer { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }

/* ───────── 11. 无障碍 & 减少动效 ───────── */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}
/* 低性能设备 / 关闭手绘滤镜 */
html.no-rough .sketch::before,
html.no-rough .card::before,
html.no-rough .modal-box::before { filter: none; }

/* ───────── 12. 手绘描边补齐：按钮 / 标签 / 侧栏导航项 ─────────
   与 .card / .stat-card / .panel 同一手法：真实 border 透明化，
   改由伪元素承载 feTurbulence 抖动描边——文字保持清晰、尺寸不变。
   （<input> 是替换元素，不支持 ::after，故输入框仍用直边描边） */
.btn, .chip, .nav-item { position: relative; }
.btn::after, .chip::after, .nav-item::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 2.5px solid var(--stroke);
  border-radius: inherit;
  filter: url(#rough);
  pointer-events: none;
}
.btn { border-color: transparent; }

.chip { border-color: transparent; }
.chip::after { border-width: 2px; border-color: var(--stroke-soft); }
.chip.d1::after { border-color: var(--ok); }
.chip.d2::after { border-color: var(--accent); }
.chip.d3::after { border-color: var(--warn); }
.chip.d4::after { border-color: var(--danger); }

.nav-item::after { border-color: transparent; }
.nav-item.on { border-color: transparent; box-shadow: var(--shadow); }
.nav-item.on::after { border-color: var(--stroke); }

html.no-rough .btn::after,
html.no-rough .chip::after,
html.no-rough .nav-item::after { filter: none; }