/* =============================================================
   小熊 · 知识小窝 —— 全局样式
   风格：暖色活力 + 企业级排版 + 手绘插画 + 细腻动效
   响应式：clamp 流式字号 + 弹性栅格，手机/电脑风格统一，不忽大忽小
   ============================================================= */

:root {
  /* 品牌暖色 */
  --brand: #f5973b;
  --brand-2: #fbb84b;
  --brand-grad: linear-gradient(135deg, #ff8a3d 0%, #fbb84b 100%);
  --brand-weak: #fff3e6;

  /* 文字 / 中性 */
  --ink: #20232b;
  --ink-2: #5a6172;
  --ink-3: #939aa8;
  --line: #efe9e0;
  --line-2: #f5f1ea;
  --bg: #ffffff;
  --bg-warm: #fff9f1;

  /* 内容类型色 */
  --t-article: #4f7be8;
  --t-pdf: #f0584b;
  --t-video: #9166e0;
  --t-image: #1db48e;

  --radius-s: 10px;
  --radius: 16px;
  --radius-l: 22px;

  --shadow-s: 0 2px 10px rgba(60, 40, 20, .06);
  --shadow: 0 14px 36px rgba(60, 40, 20, .10);
  --shadow-l: 0 28px 64px rgba(60, 40, 20, .18);
  --shadow-brand: 0 10px 24px rgba(245, 151, 59, .35);

  --maxw: 1180px;
  --header-h: 72px;
  --ease: cubic-bezier(.22, .61, .36, 1);

  font-size: clamp(15px, 0.55rem + 0.6vw, 17px);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, system-ui, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.7;
  -webkit-font-smoothing: antialiased; overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button, input, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
::selection { background: var(--brand-weak); }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(18px, 4vw, 36px); }
.ic { width: 1.15em; height: 1.15em; display: inline-block; vertical-align: -0.18em; flex: none; }

/* 插画尺寸 */
.art-bear { display: block; width: 100%; height: 100%; }
.art-thumb { display: block; width: 100%; height: 100%; }

/* 头像图片（圆形） */
.avatar-img { width: 100%; height: 100%; border-radius: 50%; object-fit: cover; display: block; background: var(--brand-weak); }
.logo .mark { border-radius: 50%; overflow: hidden; }
.login-mark { border-radius: 50%; overflow: hidden; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50; height: var(--header-h); display: flex; align-items: center;
  background: rgba(255, 255, 255, .82); backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px); border-bottom: 1px solid var(--line);
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.logo { display: flex; align-items: center; gap: 11px; font-weight: 800; font-size: 1.2rem; letter-spacing: .2px; }
.logo .mark { width: 40px; height: 40px; flex: none; filter: drop-shadow(0 4px 8px rgba(245, 151, 59, .3)); transition: transform .35s var(--ease); }
.logo:hover .mark { transform: rotate(-8deg) scale(1.04); }
.logo .name { background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.logo .sub { color: var(--ink-3); font-weight: 500; font-size: .8rem; letter-spacing: .5px; margin-left: 8px; -webkit-text-fill-color: var(--ink-3); }
.logo .sub:empty { margin-left: 0; }
.nav { display: flex; align-items: center; gap: 4px; }
.nav a { padding: 9px 16px; border-radius: 999px; color: var(--ink-2); font-size: .94rem; font-weight: 600; transition: color .2s var(--ease), background .2s var(--ease); }
.nav a:hover { color: var(--brand); background: var(--brand-weak); }

/* ---------- 英雄区 ---------- */
.hero { position: relative; overflow: hidden; background: var(--bg-warm); border-bottom: 1px solid var(--line); }
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(820px 460px at 50% -20%, rgba(255, 138, 61, .12), transparent 62%),
    radial-gradient(620px 360px at 50% 130%, rgba(29, 180, 142, .07), transparent 60%);
}
.hero .container { position: relative; }
.hero-inner { position: relative; isolation: isolate; padding: clamp(56px, 9vw, 112px) 0; max-width: 760px; margin: 0 auto; text-align: center; }
.hero-inner > :not(.logo-cloud) { position: relative; z-index: 1; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; padding: 7px 16px; border-radius: 999px;
  background: #fff; border: 1px solid var(--line); color: var(--ink-2); font-size: .84rem; font-weight: 600;
  margin-bottom: 24px; box-shadow: var(--shadow-s);
}
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); line-height: 1.18; font-weight: 900; letter-spacing: -.02em; margin-bottom: 20px; min-height: 2.36em; }
.hero h1 .hl { background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero h1 .typed { -webkit-text-fill-color: transparent; }
.tw-caret { display: inline-block; width: 3px; height: 1em; margin-left: 5px; border-radius: 2px; background: var(--brand); vertical-align: -0.12em; animation: blink 1s step-end infinite; }
.hero .lead { font-size: clamp(1.02rem, 1.6vw, 1.18rem); color: var(--ink-2); max-width: 50ch; margin: 0 auto 30px; }

.logo-cloud {
  position: absolute;
  z-index: 0;
  inset: clamp(12px, 2vw, 24px) -132px 18px;
  pointer-events: none;
}
.tool-logo {
  --size: 50px;
  --delay: 0s;
  --dur: 6.8s;
  position: absolute;
  display: grid;
  place-items: center;
  width: var(--size);
  height: var(--size);
  border: 1px solid rgba(239, 233, 224, .96);
  border-radius: 18px;
  background: rgba(255, 255, 255, .78);
  box-shadow: 0 14px 34px rgba(60, 40, 20, .12);
  backdrop-filter: blur(12px) saturate(150%);
  -webkit-backdrop-filter: blur(12px) saturate(150%);
  opacity: .88;
  animation: toolFloat var(--dur) ease-in-out infinite var(--delay);
}
.tool-logo::after {
  content: "";
  position: absolute;
  inset: 7px;
  border-radius: 13px;
  background: linear-gradient(135deg, rgba(255, 138, 61, .13), rgba(29, 180, 142, .08));
  opacity: 0;
  transition: opacity .25s var(--ease);
}
.tool-logo img {
  position: relative;
  z-index: 1;
  width: 58%;
  height: 58%;
  object-fit: contain;
  animation: none;
}
.tool-logo.spin-slow img { animation: toolSpin 36s linear infinite; }
.tool-logo.spin-reverse img { animation: none; }
.tool-logo.p1 { --size: 46px; --delay: -.4s; --dur: 7.3s; left: -22px; top: 7%; }
.tool-logo.p2 { --size: 54px; --delay: -1.2s; --dur: 6.7s; right: -26px; top: 9%; }
.tool-logo.p3 { --size: 62px; --delay: -.8s; --dur: 7.8s; left: -122px; top: 35%; }
.tool-logo.p4 { --size: 58px; --delay: -2s; --dur: 7.1s; right: -128px; top: 34%; }
.tool-logo.p5 { --size: 46px; --delay: -1.6s; --dur: 6.2s; left: -54px; top: 68%; }
.tool-logo.p6 { --size: 50px; --delay: -2.5s; --dur: 7.6s; right: -58px; top: 68%; }
.tool-logo.p7 { --size: 38px; --delay: -3.2s; --dur: 8.4s; left: 13%; top: 2%; opacity: .68; }
.tool-logo.p8 { --size: 40px; --delay: -2.8s; --dur: 7.9s; right: 12%; top: 2%; opacity: .7; }
.tool-logo.p9 { --size: 38px; --delay: -.9s; --dur: 6.9s; left: 6%; top: 82%; opacity: .72; }
.tool-logo.p10 { --size: 42px; --delay: -3.6s; --dur: 8.2s; right: 7%; top: 83%; opacity: .72; }
.tool-logo.p11 { --size: 34px; --delay: -1.8s; --dur: 7.2s; left: 23%; top: 76%; opacity: .58; }
.tool-logo.p12 { --size: 36px; --delay: -3s; --dur: 8.7s; right: 24%; top: 75%; opacity: .56; }

.search-box {
  display: flex; align-items: center; gap: 8px; max-width: 540px; margin: 0 auto; background: #fff;
  border: 1px solid var(--line); border-radius: 999px; padding: 7px 7px 7px 18px; box-shadow: var(--shadow);
  transition: box-shadow .25s var(--ease), border-color .2s;
}
.search-box:focus-within { border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-weak); }
.search-box > .ic { color: var(--ink-3); }
.search-box input { flex: 1; border: none; outline: none; background: none; font-size: 1rem; padding: 7px 4px; }
.search-box button {
  display: inline-flex; align-items: center; gap: 7px; background: var(--brand-grad); color: #fff;
  font-weight: 700; padding: 11px 22px; border-radius: 999px; box-shadow: var(--shadow-brand);
  transition: transform .15s var(--ease), filter .2s;
}
.search-box button:hover { transform: translateY(-1px); filter: brightness(1.04); }
.search-box button:active { transform: scale(.98); }

.hero-stats { display: flex; justify-content: center; gap: clamp(26px, 5vw, 52px); margin-top: 40px; flex-wrap: wrap; }
.hero-stats .stat strong { display: block; font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 900; letter-spacing: -.02em; color: var(--brand); }
.hero-stats .stat span { font-size: .85rem; color: var(--ink-3); }

/* 主视觉插画 */
.hero-art { position: relative; display: flex; justify-content: center; align-items: center; padding: 20px 0; }
.hero-art .art-hero { width: min(460px, 100%); height: auto; overflow: visible; filter: drop-shadow(0 20px 40px rgba(60, 40, 20, .12)); }
.hero-art .hchip { transform-box: fill-box; transform-origin: center; }
.hero-art .hchip.f1 { animation: float 6s ease-in-out infinite; }
.hero-art .hchip.f2 { animation: float 7s ease-in-out infinite reverse; }
.hero-art .hchip.f3 { animation: float 5.4s ease-in-out infinite .4s; }
.hero-art .hchip.f4 { animation: float 6.6s ease-in-out infinite reverse .2s; }
.art-bear.bob { animation: bob 4s ease-in-out infinite; }

/* ---------- 区块标题 + 筛选 ---------- */
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding: clamp(36px, 5vw, 56px) 0 18px; }
.section-head h2 { font-size: clamp(1.4rem, 2.6vw, 1.9rem); font-weight: 900; letter-spacing: -.01em; display: flex; align-items: center; gap: 10px; }
.section-head h2::before { content: ""; width: 6px; height: 1.1em; border-radius: 4px; background: var(--brand-grad); }
.section-head .hint { color: var(--ink-3); font-size: .9rem; }
.filter { display: flex; flex-wrap: wrap; gap: 8px; padding-bottom: 8px; }
.chip {
  display: inline-flex; align-items: center; gap: 7px; padding: 9px 16px; border-radius: 999px;
  font-size: .9rem; font-weight: 600; color: var(--ink-2); border: 1px solid var(--line); background: #fff; transition: all .2s var(--ease);
}
.chip .ic { width: 1.05em; height: 1.05em; }
.chip:hover { border-color: var(--brand); color: var(--brand); transform: translateY(-1px); }
.chip.active { background: var(--brand-grad); color: #fff; border-color: transparent; box-shadow: var(--shadow-brand); }

/* ---------- 内容栅格 ---------- */
.grid { display: grid; gap: clamp(18px, 2vw, 26px); grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); padding: 14px 0 70px; }
.card {
  display: flex; flex-direction: column; background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; cursor: pointer; box-shadow: var(--shadow-s);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: #f3ddc4; }
.card-media { position: relative; aspect-ratio: 16 / 9; overflow: hidden; }
.card-media > img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s var(--ease); }
.card-media .art-thumb { transition: transform .5s var(--ease); }
.card:hover .card-media > img, .card:hover .card-media .art-thumb { transform: scale(1.05); }

.type-badge {
  position: absolute; top: 12px; left: 12px; display: inline-flex; align-items: center; gap: 5px;
  padding: 5px 11px; border-radius: 8px; font-size: .75rem; font-weight: 700;
  background: rgba(255, 255, 255, .94); color: var(--ink); box-shadow: var(--shadow-s); backdrop-filter: blur(4px);
}
.type-badge .ic { width: 1em; height: 1em; }
.type-badge.k-article { color: var(--t-article); }
.type-badge.k-pdf { color: var(--t-pdf); }
.type-badge.k-video { color: var(--t-video); }
.type-badge.k-image { color: var(--t-image); }

.card-body { padding: 18px 18px 16px; display: flex; flex-direction: column; gap: 9px; flex: 1; }
.card-body h3 { font-size: 1.1rem; font-weight: 800; line-height: 1.4; letter-spacing: -.01em; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card-body p { font-size: .92rem; color: var(--ink-2); line-height: 1.6; flex: 1; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card-meta { display: flex; align-items: center; gap: 10px; font-size: .8rem; color: var(--ink-3); padding-top: 12px; border-top: 1px solid var(--line-2); }
.card-meta .cat { color: var(--brand); font-weight: 700; }
.card-meta .dot { width: 3px; height: 3px; border-radius: 50%; background: var(--line); }
.card-meta .views { display: inline-flex; align-items: center; gap: 4px; margin-left: auto; }

.empty { grid-column: 1 / -1; text-align: center; padding: 80px 20px; color: var(--ink-3); }
.empty .art-bear { width: 92px; height: 92px; margin: 0 auto 14px; opacity: .9; }
.loader { grid-column: 1 / -1; display: flex; align-items: center; justify-content: center; gap: 10px; padding: 70px; color: var(--ink-3); font-size: .92rem; }
.loader .ring { width: 20px; height: 20px; border: 2.5px solid var(--brand-weak); border-top-color: var(--brand); border-radius: 50%; animation: spin .8s linear infinite; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg-warm); border-top: 1px solid var(--line); padding: 44px 0; }
.site-footer .container { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 14px; color: var(--ink-3); font-size: .88rem; }
.site-footer .logo .mark { width: 34px; height: 34px; }

/* ---------- 弹窗 ---------- */
.modal { position: fixed; inset: 0; z-index: 100; display: none; align-items: center; justify-content: center; padding: 20px; }
.modal.open { display: flex; }
.modal-overlay { position: absolute; inset: 0; background: rgba(30, 20, 12, .5); backdrop-filter: blur(5px); animation: fade .25s var(--ease); }
.modal-card { position: relative; z-index: 1; width: min(940px, 100%); max-height: 90vh; overflow: auto; background: #fff; border-radius: var(--radius-l); box-shadow: var(--shadow-l); animation: rise .32s var(--ease); }
.modal-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; padding: 24px 26px 16px; }
.modal-head .mt { font-size: 1.45rem; font-weight: 900; letter-spacing: -.01em; line-height: 1.3; }
.modal-head .mc { font-size: .82rem; color: var(--brand); font-weight: 700; margin-bottom: 6px; }
.modal-close { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 10px; background: var(--brand-weak); color: var(--brand); flex: none; transition: all .2s var(--ease); }
.modal-close:hover { background: var(--brand); color: #fff; transform: rotate(90deg); }
.modal-viewer { padding: 0 26px; }
.modal-viewer img { width: 100%; border-radius: var(--radius); }
.modal-viewer video { width: 100%; border-radius: var(--radius); background: #000; }
.modal-viewer iframe { width: 100%; height: 70vh; border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg-warm); }
.modal-viewer .article-body { white-space: pre-wrap; line-height: 1.85; color: var(--ink); font-size: 1.04rem; }
.modal-foot { padding: 20px 26px 26px; display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.modal-foot .desc { color: var(--ink-2); flex: 1; min-width: 200px; font-size: .95rem; }

/* ---------- 按钮 ---------- */
.btn { display: inline-flex; align-items: center; gap: 8px; justify-content: center; padding: 11px 22px; border-radius: 999px; font-weight: 700; font-size: .94rem; transition: all .2s var(--ease); }
.btn-primary { background: var(--brand-grad); color: #fff; box-shadow: var(--shadow-brand); }
.btn-primary:hover { transform: translateY(-2px); filter: brightness(1.04); }
.btn-soft { background: var(--brand-weak); color: var(--brand); }
.btn-soft:hover { background: var(--brand); color: #fff; }

/* ---------- 动效 ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .55s var(--ease), transform .55s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes rise { from { opacity: 0; transform: translateY(14px) scale(.99); } to { opacity: 1; transform: none; } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes bob { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }
@keyframes float { 0%, 100% { transform: translateY(0) rotate(-3deg); } 50% { transform: translateY(-14px) rotate(3deg); } }
@keyframes toolSpin { to { transform: rotate(360deg); } }
@keyframes toolFloat {
  0%, 100% { transform: translate3d(0, 0, 0); }
  50% { transform: translate3d(0, -8px, 0); }
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero-inner { max-width: none; padding-bottom: 8px; }
  .logo-cloud {
    position: relative;
    inset: auto;
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 9px;
    max-width: 430px;
    margin: -8px auto 22px;
  }
  .tool-logo,
  .tool-logo.p1,
  .tool-logo.p2,
  .tool-logo.p3,
  .tool-logo.p4,
  .tool-logo.p5,
  .tool-logo.p6,
  .tool-logo.p7,
  .tool-logo.p8,
  .tool-logo.p9,
  .tool-logo.p10,
  .tool-logo.p11,
  .tool-logo.p12 {
    position: relative;
    inset: auto;
    width: 42px;
    height: 42px;
    justify-self: center;
    opacity: .9;
    border-radius: 14px;
  }
  .tool-logo.spin-slow img,
  .tool-logo.spin-reverse img {
    animation: none;
  }
  .hero-art { order: -1; padding: 28px 0 0; }
  .hero-art .art-hero { width: min(360px, 78%); }
  .hero-stats { margin-top: 30px; }
}
@media (max-width: 640px) {
  :root { --header-h: 60px; }
  .site-header .container { gap: 8px; padding-inline: 12px; }
  .logo { gap: 7px; min-width: max-content; font-size: 1rem; }
  .logo .name { white-space: nowrap; }
  .logo .sub { display: none; }
  .nav { gap: 2px; overflow-x: auto; scrollbar-width: none; }
  .nav::-webkit-scrollbar { display: none; }
  .nav a { flex: none; white-space: nowrap; padding: 7px 8px; font-size: .82rem; }
  .logo-cloud { grid-template-columns: repeat(4, minmax(0, 1fr)); max-width: 256px; margin-top: -2px; }
  .tool-logo:nth-child(n+9) { display: none; }
  .filter {
    flex-wrap: nowrap;
    overflow-x: auto;
    margin-inline: -18px;
    padding: 0 18px 12px;
    scroll-snap-type: x proximity;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .filter::-webkit-scrollbar {
    display: none;
  }
  .filter .chip {
    flex: 0 0 auto;
    scroll-snap-align: start;
  }
  .grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    padding-top: 12px;
  }
  .card {
    border-radius: 14px;
  }
  .card:hover {
    transform: none;
  }
  .card-body {
    padding: 12px 11px 11px;
    gap: 6px;
  }
  .card-body h3 {
    font-size: .92rem;
    line-height: 1.35;
  }
  .card-body p {
    font-size: .76rem;
    line-height: 1.45;
  }
  .card-meta {
    gap: 5px;
    padding-top: 8px;
    font-size: .68rem;
    line-height: 1.35;
  }
  .card-meta .dot {
    display: none;
  }
  .card-meta .views {
    width: 100%;
    margin-left: 0;
    justify-content: flex-end;
  }
  .type-badge {
    top: 8px;
    left: 8px;
    padding: 4px 8px;
    border-radius: 7px;
    font-size: .66rem;
  }
  .modal-card { border-radius: var(--radius); }
  .modal-viewer iframe { height: 62vh; }
}
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; scroll-behavior: auto; } }