/* ============================================================
   Front — Shared Base Styles (v4)
   Design: Royal-blue light theme, premium tutorial site
   Glassmorphism header, smooth animations, light-only
   ============================================================ */

/* ---------- CSS Variables — Royal Blue Light Palette ---------- */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #eff6ff;
  --color-primary-soft: #bfdbfe;
  --color-primary-glow: rgba(37,99,235,.12);
  --color-accent: #0ea5e9;
  --color-accent-dark: #0284c7;
  --color-accent-light: #f0f9ff;
  --color-success: #10b981;
  --color-danger: #f43f5e;
  --color-warning: #f59e0b;
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #eff6ff;
  --color-bg-card: #ffffff;
  --color-bg-hover: #f0f7ff;
  --color-bg-glass: rgba(255,255,255,.85);
  --color-text: #334155;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-heading: #0f172a;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-border-hover: #93c5fd;
  --shadow-none: 0 0 0 transparent;
  --shadow-xs: 0 1px 2px rgba(15,23,42,.05);
  --shadow-sm: 0 1px 3px rgba(15,23,42,.06), 0 1px 2px rgba(15,23,42,.03);
  --shadow-md: 0 2px 8px rgba(15,23,42,.07), 0 1px 3px rgba(15,23,42,.04);
  --shadow-lg: 0 4px 18px rgba(15,23,42,.09), 0 2px 6px rgba(15,23,42,.04);
  --shadow-xl: 0 8px 32px rgba(15,23,42,.12), 0 3px 10px rgba(15,23,42,.05);
  --shadow-card: 0 1px 2px rgba(15,23,42,.03), 0 2px 4px rgba(15,23,42,.03);
  --shadow-card-hover: 0 4px 16px rgba(37,99,235,.14), 0 2px 6px rgba(15,23,42,.06);
  --shadow-glow: 0 0 0 3px rgba(37,99,235,.16);
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Fira Code", Consolas, monospace;
  --max-width: 1280px;
  --max-width-narrow: 800px;
  --header-height: 68px;
  --transition-fast: .15s cubic-bezier(.4,0,.2,1);
  --transition-base: .25s cubic-bezier(.4,0,.2,1);
  --transition-slow: .4s cubic-bezier(.25,.46,.45,.94);
}

/* ---------- Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}

/* ---------- Import Inter font ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* ---------- Reset & Base ---------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:var(--font-sans);font-size:16px;line-height:1.75;color:var(--color-text);background:var(--color-bg);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;overflow-x:hidden}
::selection{background:var(--color-primary-soft);color:var(--color-primary-dark)}
::-moz-selection{background:var(--color-primary-soft);color:var(--color-primary-dark)}
a{color:var(--color-primary);text-decoration:none;transition:color var(--transition-fast)}
a:hover{color:var(--color-primary-dark)}
img{max-width:100%;height:auto;display:block}
ul,ol{list-style:none}
h1,h2,h3,h4,h5,h6{color:var(--color-heading);line-height:1.3;font-weight:700;letter-spacing:-.01em}
h1{font-size:clamp(1.5rem,4vw,2.25rem)}
h2{font-size:clamp(1.25rem,3vw,1.65rem)}
h3{font-size:clamp(1.05rem,2vw,1.25rem)}
h2 .cjhvxt{display:inline-block;margin-right:.35rem;font-size:.85em;vertical-align:middle;transition:transform var(--transition-base)}
h2:hover .cjhvxt{transform:scale(1.15) rotate(-5deg)}
p{margin-bottom:1rem}
strong{font-weight:600}
code{font-family:var(--font-mono);font-size:.875em;background:var(--color-bg-tertiary);color:var(--color-primary);padding:.15em .5em;border-radius:var(--radius-xs);border:1px solid var(--color-border)}
pre{background:var(--color-bg-secondary);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:1.25rem;overflow-x:auto;margin-bottom:1.5rem;font-size:.9rem;line-height:1.6}
pre code{background:none;color:var(--color-text);padding:0;border:none}
blockquote{border-left:4px solid var(--color-primary);padding:.75rem 1.25rem;margin:1.5rem 0;color:var(--color-text-secondary);background:var(--color-bg-secondary);border-radius:0 var(--radius-sm) var(--radius-sm) 0}
hr{border:none;border-top:1px solid var(--color-border);margin:2.5rem 0}

/* ---------- Container ---------- */
.cu4qmz{max-width:var(--max-width);margin:0 auto;padding:0 1.5rem}
@media(max-width:768px){.cu4qmz{padding:0 1rem}}

/* ---------- Buttons ---------- */
.cq4pbh{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.72rem 1.75rem;border-radius:var(--radius-full);font-size:.9rem;font-weight:600;cursor:pointer;border:1.5px solid transparent;transition:all var(--transition-base);text-decoration:none;line-height:1.5;white-space:nowrap;position:relative;overflow:hidden;letter-spacing:.01em}
.cq4pbh::after{content:"";position:absolute;inset:0;background:radial-gradient(circle at center,rgba(255,255,255,.3) 0%,transparent 70%);opacity:0;transition:opacity var(--transition-base)}
.cq4pbh:hover::after{opacity:1}
.chy9g6{background:linear-gradient(135deg,var(--color-primary),var(--color-primary-dark));color:#fff;box-shadow:0 2px 12px var(--color-primary-glow)}
.chy9g6:hover{color:#fff;box-shadow:0 6px 24px var(--color-primary-glow);transform:translateY(-2px)}
.cv9vwx{border-color:var(--color-border);color:var(--color-text);background:var(--color-bg-card)}
.cv9vwx:hover{border-color:var(--color-primary);color:var(--color-primary);background:var(--color-primary-light);box-shadow:0 4px 16px var(--color-primary-glow)}
.c38cv9{background:linear-gradient(135deg,var(--color-accent),var(--color-accent-dark));color:#fff;box-shadow:0 2px 12px rgba(14,165,233,.25)}
.c38cv9:hover{color:#fff;box-shadow:0 6px 24px rgba(14,165,233,.4);transform:translateY(-2px)}
.ce3vka{padding:.4rem 1rem;font-size:.82rem}
.ca2ct7{padding:.82rem 2.1rem;font-size:1rem}
.cq4pbh:active{transform:scale(.97)}
@media(max-width:768px){.cq4pbh{min-height:44px}.ca2ct7{min-height:48px;padding:.9rem 2rem}}

/* ---------- Section Spacing ---------- */
.cz5373{padding:5rem 0}
.cdhek3{padding:3.5rem 0}
.cj6mwe{background:var(--color-bg-secondary);border-top:1px solid var(--color-border-light);border-bottom:1px solid var(--color-border-light);position:relative}
.cj6mwe::before{content:"";position:absolute;inset:0;pointer-events:none;background-image:radial-gradient(var(--color-border) .5px,transparent .5px);background-size:20px 20px;opacity:.35}
@media(max-width:768px){.cz5373{padding:2rem 0}.cdhek3{padding:1.5rem 0}}

/* ============================================================
   HEADER — Premium Glass Morphism
   ============================================================ */
.cu6zxn{position:sticky;top:0;z-index:100;background:var(--color-bg-glass);border-bottom:1px solid transparent;backdrop-filter:blur(24px) saturate(180%);-webkit-backdrop-filter:blur(24px) saturate(180%);transition:border-color var(--transition-base),box-shadow var(--transition-base),background var(--transition-base)}
.cu6zxn.ccvjk4{border-bottom-color:var(--color-border);box-shadow:0 1px 8px rgba(15,23,42,.06);background:var(--color-bg-glass)}
.cu6zxn .cu4qmz{display:flex;align-items:center;height:var(--header-height);gap:1.5rem}
.cwfffr{display:flex;align-items:center;gap:.6rem;font-weight:800;font-size:1.15rem;color:var(--color-heading);flex-shrink:0;transition:opacity var(--transition-fast)}
.cwfffr:hover{opacity:.82;color:var(--color-heading)}
.cwfffr img{height:32px;width:auto;border-radius:var(--radius-xs)}
.cwfffr .cvwa48{white-space:nowrap;background:linear-gradient(135deg,var(--color-primary),#0ea5e9);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.czzs8b{display:flex;align-items:center;gap:.15rem}
.czzs8b a,.chau6d .cvtpqx{display:inline-flex;align-items:center;padding:.45rem .9rem;border-radius:var(--radius-full);font-size:.88rem;font-weight:500;color:var(--color-text-secondary);transition:all var(--transition-fast);position:relative}
.czzs8b a::after,.chau6d .cvtpqx::after{content:"";position:absolute;bottom:.06rem;left:50%;width:0;height:2.5px;background:var(--color-primary);border-radius:2px;transform:translateX(-50%);transition:width var(--transition-base),height var(--transition-base),box-shadow var(--transition-base)}
.czzs8b a:hover::after,.chau6d .cvtpqx:hover::after{width:calc(100% - 1.8rem)}
.czzs8b a:hover,.chau6d .cvtpqx:hover{color:var(--color-primary);background:var(--color-bg-hover)}
.czzs8b a.cvf7wf,.chau6d.c6bzjp.cvf7wf>.cvtpqx{color:var(--color-primary);font-weight:600}
.czzs8b a.cvf7wf::after,.chau6d.c6bzjp.cvf7wf>.cvtpqx::after{width:calc(100% - .6rem);height:3px;background:linear-gradient(90deg,var(--color-primary),#0ea5e9);border-radius:3px;box-shadow:0 1px 8px var(--color-primary-glow)}
.cabezr{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;border-radius:var(--radius-full);border:none;background:none;color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition-fast);margin-left:.5rem;flex-shrink:0}
.cabezr:hover{color:var(--color-primary);background:var(--color-bg-hover)}
.c4jhrz{display:inline-flex;align-items:center;gap:10px;margin-left:auto;flex-shrink:0}
.cd9z2s{display:inline-flex;align-items:center;height:36px;padding:0 16px;border-radius:var(--radius-full);border:none;background:linear-gradient(135deg,var(--color-primary),#1d4ed8);color:#fff;cursor:pointer;transition:all var(--transition-base);margin-left:0;flex-shrink:0;text-decoration:none;font-size:13px;font-weight:600;white-space:nowrap;box-shadow:0 2px 8px var(--color-primary-glow)}
.cd9z2s:hover{background:linear-gradient(135deg,var(--color-primary-dark),#1e40af);color:#fff;box-shadow:0 4px 16px var(--color-primary-glow);transform:translateY(-1px)}
.cf8pr9{display:none;flex-direction:column;justify-content:center;align-items:center;gap:5px;width:38px;height:38px;background:none;border:none;border-radius:var(--radius-sm);cursor:pointer;padding:0;flex-shrink:0;transition:background var(--transition-fast)}
.cf8pr9:hover{background:var(--color-bg-hover)}
.cf8pr9 span{display:block;width:20px;height:2px;background:var(--color-text);border-radius:1px;transition:all var(--transition-fast)}
.cf8pr9[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.cf8pr9[aria-expanded="true"] span:nth-child(2){opacity:0}
.cf8pr9[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.chau6d.c6bzjp{cursor:pointer;position:relative;display:inline-flex;align-items:center;gap:.15rem}
.chau6d .cgzm6p{transition:transform var(--transition-fast);flex-shrink:0;margin-left:-.25rem}
.chau6d.c6bzjp:hover .cgzm6p{transform:rotate(180deg)}
.ctm9qb{position:absolute;top:calc(100% + .35rem);left:0;min-width:170px;background:var(--color-bg-card);border:1px solid var(--color-border);border-radius:var(--radius-md);box-shadow:var(--shadow-xl);padding:.4rem;opacity:0;visibility:hidden;transform:translateY(6px);transition:all var(--transition-base);z-index:110}
.chau6d.c6bzjp:hover .ctm9qb{opacity:1;visibility:visible;transform:translateY(0)}
.ctm9qb a{display:block!important;padding:.5rem .9rem;border-radius:var(--radius-sm);font-size:.85rem;font-weight:500;color:var(--color-text-secondary);white-space:nowrap;transition:all var(--transition-fast)}
.ctm9qb a:hover{color:var(--color-primary);background:var(--color-primary-light)}
.ctm9qb a.cvf7wf{color:var(--color-primary);font-weight:600;background:transparent;box-shadow:inset 3px 0 0 var(--color-primary)}

@media(max-width:768px){
  .czzs8b{display:none;position:absolute;top:var(--header-height);left:0;right:0;background:var(--color-bg);border-bottom:1px solid var(--color-border);flex-direction:column;padding:1rem;gap:.5rem;box-shadow:var(--shadow-lg);border-radius:0 0 var(--radius-lg) var(--radius-lg)}
  .czzs8b.cw38ur{display:flex}
  .czzs8b a{width:100%;min-height:44px;display:flex;align-items:center;justify-content:flex-start;border-radius:var(--radius-md)}
  .czzs8b a::after{display:none}
  .cabezr{display:none}
  .cf8pr9{display:flex}
  .chau6d.c6bzjp{flex-direction:column;align-items:stretch}
  .chau6d.c6bzjp .cvtpqx{width:100%}
  .chau6d .cvtpqx::after{display:none}
  .ctm9qb{position:static;box-shadow:none;border:none;background:transparent;opacity:1;visibility:visible;transform:none;padding:.25rem 0 .25rem 1rem;display:none}
  .chau6d.c6bzjp:hover .ctm9qb,.chau6d.c6bzjp.cw38ur .ctm9qb{display:block}
}

/* ============================================================
   FOOTER — Deep Navy Anchor (v5)
   亮色页面的深色收尾，形成专业对比锚点
   ============================================================ */
.c66pqu{background:linear-gradient(180deg,#101d3d 0%,#0b1530 100%);padding:4.25rem 0 0;margin-top:5rem;position:relative;overflow:hidden}
.c66pqu::before{content:"";position:absolute;top:0;left:0;right:0;height:2px;background:linear-gradient(90deg,transparent 10%,#2563eb 35%,#38bdf8 50%,#2563eb 65%,transparent 90%);opacity:.8}
.c66pqu::after{content:"";position:absolute;top:-160px;right:-120px;width:440px;height:440px;border-radius:50%;background:radial-gradient(circle,rgba(37,99,235,.3) 0%,transparent 65%);filter:blur(60px);pointer-events:none}
.cjggja{display:grid;grid-template-columns:1.8fr 1fr 1fr 1fr;gap:2.5rem;padding-bottom:2.75rem;position:relative;z-index:1}
.c55j2n{display:flex;align-items:center;gap:.55rem;font-weight:800;font-size:1.05rem;color:#f1f5f9;margin-bottom:.9rem}
.c55j2n img{height:30px;width:auto;border-radius:var(--radius-xs);box-shadow:0 0 0 1px rgba(255,255,255,.14)}
.c99exa h4{font-size:.74rem;font-weight:700;text-transform:uppercase;letter-spacing:.14em;color:#7db4fb;margin-bottom:1.1rem}
.c99exa h4::after{content:"";display:block;width:22px;height:2px;background:linear-gradient(90deg,#3b82f6,#38bdf8);border-radius:1px;margin-top:.4rem}
.c99exa ul li{margin-bottom:.55rem}
.c99exa ul li a{font-size:.875rem;color:#c3cde4;transition:color var(--transition-fast),transform var(--transition-fast);display:inline-block}
.c99exa ul li a:hover{color:#7dd3fc;transform:translateX(2px)}
.cyezn3 p{font-size:.875rem;color:#aab6d3;line-height:1.75}
.c2qqdj{font-size:.85rem;color:#8291b4;margin-top:.4rem;line-height:1.75;max-width:38ch}
.chtt8g{display:flex;gap:.75rem;margin-top:1rem}
.chtt8g a{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:var(--radius-full);border:1px solid rgba(255,255,255,.16);color:#aab6d3;transition:all var(--transition-fast)}
.chtt8g a:hover{color:#7dd3fc;border-color:#3b82f6;background:rgba(37,99,235,.22);transform:translateY(-2px)}
.cym4vb{padding:1.4rem 0;border-top:1px solid rgba(255,255,255,.09);display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:.75rem 1.5rem;font-size:.82rem;color:#6d7ca0;position:relative;z-index:1}
.cym4vb .fcr5v8{margin:0;white-space:nowrap}
.cym4vb .chw52e{margin:0;text-align:right;max-width:62ch;line-height:1.7}
.cq9m2e{display:inline-flex;align-items:center;gap:.45rem;color:#7dd3fc;font-size:.82rem;transition:color var(--transition-fast);white-space:nowrap}
.cq9m2e:hover{color:#93c5fd}
@media(max-width:1024px){.cjggja{gap:2rem}}
@media(max-width:768px){.c66pqu{margin-top:2.5rem;padding:2.5rem 0 0}.cjggja{grid-template-columns:repeat(3,1fr);gap:2rem;padding-bottom:1.5rem}.cyezn3{grid-column:1/-1}.cym4vb{flex-direction:column;text-align:center}}
@media(max-width:480px){.cjggja{grid-template-columns:repeat(3,1fr);gap:1.25rem}.cyezn3{grid-column:1/-1}}

/* ============================================================
   BREADCRUMB — subtle background
   ============================================================ */
.ckvsuu{padding:.7rem 0;background:var(--color-bg-tertiary);border-bottom:1px solid var(--color-border-light);font-size:.83rem}
.ckvsuu a{color:var(--color-text-muted);transition:color var(--transition-fast)}
.ckvsuu a:hover{color:var(--color-primary)}
.ckvsuu .cy8eur{color:var(--color-text-muted);margin:0 .45rem;user-select:none}
.ckvsuu span{color:var(--color-text-secondary);font-weight:500}
@media(max-width:768px){.ckvsuu .cu4qmz{overflow-x:auto;white-space:nowrap;-webkit-overflow-scrolling:touch;scrollbar-width:none}.ckvsuu .cu4qmz::-webkit-scrollbar{display:none}}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.cdmhwe{position:fixed;bottom:2.5rem;right:2.5rem;width:48px;height:48px;border-radius:var(--radius-full);border:1.5px solid var(--color-border);background:var(--color-bg-card);color:var(--color-text-secondary);cursor:pointer;display:none;align-items:center;justify-content:center;box-shadow:var(--shadow-lg);transition:all var(--transition-fast);z-index:90;backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}
.cdmhwe:hover{color:var(--color-primary);border-color:var(--color-primary);box-shadow:0 4px 20px var(--color-primary-glow);transform:translateY(-3px)}
.cdmhwe.cbaau5{display:flex}

/* ============================================================
   READING PROGRESS BAR
   ============================================================ */
.c7wpyf{position:fixed;top:0;left:0;height:3px;background:linear-gradient(90deg,var(--color-primary),#0ea5e9,var(--color-accent));z-index:200;transition:width .1s linear;border-radius:0 2px 0 0;box-shadow:0 0 8px rgba(37,99,235,.3)}

/* ============================================================
   EMPTY STATE
   ============================================================ */
.cqjuf2{text-align:center;padding:5rem 1rem;color:var(--color-text-muted)}
.cfswjs{margin-bottom:1.2rem;color:var(--color-border);opacity:.5}
.cqjuf2 h3{font-size:1.2rem;color:var(--color-text-secondary);margin-bottom:.5rem}
.cqjuf2 p{font-size:.92rem;margin-bottom:1.5rem}
.cqjuf2 .cq4pbh{margin:0 auto}

/* ============================================================
   TAG PILL — Premium pill style
   ============================================================ */
.cw3jze{display:inline-flex;align-items:center;gap:.35rem;padding:.42rem 1rem;background:var(--color-bg-secondary);border:1.5px solid var(--color-border);border-radius:var(--radius-full);font-size:.82rem;font-weight:500;color:var(--color-text-secondary);transition:all var(--transition-base);position:relative;overflow:hidden}
.cw3jze::before{content:"";position:absolute;inset:0;background:linear-gradient(135deg,var(--color-primary-light),transparent 60%);opacity:0;transition:opacity var(--transition-base)}
.cw3jze:hover{border-color:var(--color-primary);color:var(--color-primary);transform:translateY(-3px);box-shadow:0 4px 16px var(--color-primary-glow)}
.cw3jze:hover::before{opacity:1}
.chzb47{display:flex;flex-wrap:wrap;justify-content:center;gap:.7rem;padding:1rem 0}

/* ============================================================
   SECTION HEADER
   ============================================================ */
.c5bu5p{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:2.5rem;flex-wrap:wrap;gap:.75rem}
.c5bu5p h2{font-size:1.65rem;font-weight:800}
.c5bu5p p{color:var(--color-text-secondary);margin:0}
.ca2tp6{color:var(--color-text-secondary);margin:0}
.c2hw9z{font-size:.9rem;color:var(--color-primary);font-weight:600;white-space:nowrap;transition:all var(--transition-fast)}
.c2hw9z:hover{gap:.4rem;color:var(--color-primary-dark);letter-spacing:.02em}
@media(max-width:768px){.c5bu5p{flex-direction:column;align-items:flex-start;margin-bottom:1.5rem}.c5bu5p h2{font-size:clamp(1.15rem,3.5vw,1.5rem)}}

/* ============================================================
   SCROLL ANIMATION
   ============================================================ */
.cdc27p{opacity:0;transform:translateY(28px);transition:opacity .65s cubic-bezier(.25,.46,.45,.94),transform .65s cubic-bezier(.25,.46,.45,.94)}
.cdc27p.cbaau5{opacity:1;transform:translateY(0)}
.cdc27p.c85rbt{transition-delay:.08s}
.cdc27p.c8nr8h{transition-delay:.16s}
.cdc27p.ckzbjq{transition-delay:.24s}
.cdc27p.cwrm7u{transition-delay:.32s}
.cdc27p.cdfq38{transition-delay:.4s}
.cdc27p.cwk693{transform:none;transition:opacity .5s ease}
.cdc27p.cc4cae{transform:translateX(-30px);transition:opacity .6s ease,transform .6s cubic-bezier(.25,.46,.45,.94)}
.cdc27p.cc4cae.cbaau5{transform:translateX(0)}
.cdc27p.c57ef4{transform:translateX(30px);transition:opacity .6s ease,transform .6s cubic-bezier(.25,.46,.45,.94)}
.cdc27p.c57ef4.cbaau5{transform:translateX(0)}

/* ============================================================
   HERO SUBPAGE — gradient + blur circle
   ============================================================ */
.cg4vfr{text-align:center;position:relative;overflow:hidden;padding:4rem 0 3rem;background:linear-gradient(180deg,var(--color-primary-light) 0%,rgba(224,242,254,.3) 40%,transparent 80%)}
.cg4vfr::before{content:"";position:absolute;top:-140px;left:50%;transform:translateX(-50%);width:600px;height:600px;background:radial-gradient(circle,var(--color-primary-soft) 0%,transparent 60%);border-radius:50%;filter:blur(80px);opacity:.45;pointer-events:none}
.cg4vfr .cu4qmz{position:relative;z-index:1}
.cg4vfr h1{font-size:2.5rem;font-weight:800;letter-spacing:-.02em;margin-bottom:.6rem}
.cg4vfr .cz4eu9{font-size:1.1rem;color:var(--color-text-secondary);max-width:620px;margin:0 auto;line-height:1.7}
@media(max-width:1024px){.cg4vfr{padding:2.5rem 0 2rem}.cg4vfr h1{font-size:clamp(1.5rem,4vw,2.25rem)}.cg4vfr::before{width:350px;height:350px;top:-80px}}
@media(max-width:768px){.cg4vfr{padding:1.5rem 0 1rem}.cg4vfr h1{font-size:1.5rem}.cg4vfr .cz4eu9{font-size:.95rem}.cg4vfr::before{width:240px;height:240px;top:-50px}}

/* ============================================================
   FEATURES GRID — colorful icons + premium cards
   ============================================================ */
.cqc22t{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:1.5rem}
.cxems8{display:flex;gap:1.35rem;padding:1.85rem;background:var(--color-bg-card);border:1.5px solid var(--color-border);border-radius:var(--radius-lg);transition:all var(--transition-base);box-shadow:var(--shadow-card);position:relative;overflow:hidden}
.cxems8::before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--color-primary),var(--color-accent));opacity:0;transition:opacity var(--transition-base)}
.cxems8:hover{transform:translateY(-6px);box-shadow:var(--shadow-xl);border-color:var(--color-primary-soft)}
.cxems8:hover::before{opacity:1}
.crschp{flex-shrink:0;width:56px;height:56px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-lg);color:var(--color-primary);font-size:1.4rem;transition:all var(--transition-base)}
.cxems8:hover .crschp{transform:scale(1.1)}
/* 5-color gradients for icon variants */
.crschp{background:linear-gradient(135deg,var(--color-primary-light),var(--color-primary-soft))}
.crschp.c8rq3v{background:linear-gradient(135deg,#dbeafe,#bfdbfe);color:#2563eb}
.crschp.c323ju{background:linear-gradient(135deg,#d1fae5,#a7f3d0);color:#059669}
.crschp.cgj6pd{background:linear-gradient(135deg,#ffedd5,#fed7aa);color:#ea580c}
.crschp.cg54x9{background:linear-gradient(135deg,#ede9fe,#ddd6fe);color:#7c3aed}
.crschp.czn9k8{background:linear-gradient(135deg,#cffafe,#a5f3fc);color:#0891b2}
.cxems8 h3{font-size:1.1rem;margin-bottom:.3rem;max-width:2.2em;line-height:1.3}
.cxems8 p{font-size:.875rem;color:var(--color-text-secondary);line-height:1.65;margin:0}
@media(max-width:1024px){.cqc22t{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}}
@media(max-width:768px){.cqc22t{grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}.cxems8{padding:1.25rem}.crschp{width:48px;height:48px}}
@media(max-width:480px){.cqc22t{grid-template-columns:1fr}}

/* ============================================================
   CTA SECTION (shared)
   ============================================================ */
.cga3pd{text-align:center;margin-top:3.5rem;padding:3.5rem 2.5rem;background:linear-gradient(135deg,var(--color-primary) 0%,#0ea5e9 50%,#38bdf8 100%);border-radius:var(--radius-xl);color:#fff;box-shadow:0 8px 32px rgba(37,99,235,.3);position:relative;overflow:hidden}
.cga3pd::before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle at 30% 20%,rgba(255,255,255,.08) 0%,transparent 50%);pointer-events:none}
.cga3pd h2{color:#fff;font-size:1.55rem;margin-bottom:.6rem}
.cga3pd p{color:rgba(255,255,255,.85);margin-bottom:1.75rem;font-size:.98rem}
@media(max-width:1024px){.cga3pd{padding:2.5rem 1.5rem}.cga3pd h2{font-size:1.3rem}}
@media(max-width:768px){.cga3pd{padding:2rem 1.25rem;margin-top:2rem}.cga3pd h2{font-size:1.2rem}.cga3pd p{font-size:.9rem}}

/* ============================================================
   UTILITY
   ============================================================ */
.cseyvy{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}
/* Skip to content link */
.cvbtdn{position:absolute;left:-9999px;top:0;z-index:9999;background:var(--color-primary,#2563eb);color:#fff;padding:.5rem 1rem;font-size:.9rem;text-decoration:none;border-radius:0 0 .3rem .3rem;transition:left 0s}
.cvbtdn:focus{left:.5rem}
/* Topic card stretch link */
.cu8rpa{position:relative}
.cg3ds5{color:inherit;text-decoration:none}
.cg3ds5::after{content:"";position:absolute;inset:0}
.c5ysae{text-align:center}
.c4b9ct{display:none!important}
@media(min-width:769px){.cz5drj{display:block}.c63mh9{display:none}}
@media(max-width:768px){.cz5drj{display:none}.c63mh9{display:block}}

/* ============================================================
   v4 ADDITIONS — Royal Blue Light design language
   ============================================================ */

/* ---------- Global scrollbar (blue, slim) ---------- */
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:#bfdbfe;border-radius:6px;border:2px solid var(--color-bg)}
::-webkit-scrollbar-thumb:hover{background:#93c5fd}
html{scrollbar-width:thin;scrollbar-color:#bfdbfe transparent}

/* ---------- Sub-page kicker chip (等宽代码风标签) ---------- */
.cz7euc{display:inline-flex;align-items:center;gap:.5rem;padding:.32rem .95rem;margin-bottom:1.15rem;font-family:var(--font-mono);font-size:.72rem;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:#1d4ed8;background:var(--color-bg-card);border:1px solid #bfdbfe;border-radius:var(--radius-full)}
.cz7euc::before{content:"";flex-shrink:0;width:7px;height:7px;border-radius:50%;background:#2563eb;box-shadow:0 0 0 3px rgba(37,99,235,.12)}

/* ---------- cg4vfr v4 refinement ---------- */
.cg4vfr h1::after{content:"";display:block;width:56px;height:3px;margin:.8rem auto 0;background:linear-gradient(90deg,#2563eb,#38bdf8);border-radius:2px}
.cg4vfr h1{margin-bottom:1.05rem}

/* ---------- Editorial numbered heading (描边编号) ---------- */
.caqkn9{font-family:var(--font-mono);font-weight:800;color:transparent;-webkit-text-stroke:1.5px #93c5fd;letter-spacing:-.02em;user-select:none}

/* ============================================================
   v4.3 HEADER 用户区（全站加载 — 从 user 模块样式迁移）
   导航登录/注册按钮 + 登录后用户菜单在全站 header 显示，
   样式必须随公共样式表加载
   ============================================================ */
.c5q8nb { display: flex; align-items: center; gap: 8px; margin-left: 8px; }

.ca2zky {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 12px 16px; border-radius: var(--radius-full); font-size: 15px; font-weight: 600;
  line-height: 1.2; text-decoration: none; cursor: pointer; border: 1px solid transparent;
  transition: all var(--transition-base); white-space: nowrap;
}
.c724ux { flex-shrink: 0; }

.cgnhj2 {
  color: var(--color-text); border-color: var(--color-border); background: var(--color-bg-card);
}
.cgnhj2:hover {
  color: var(--color-primary); border-color: var(--color-primary); background: var(--color-primary-light);
  box-shadow: 0 4px 14px var(--color-primary-glow);
}
.cud7p8 {
  color: #fff; background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  box-shadow: 0 2px 8px var(--color-primary-glow);
}
.cud7p8:hover {
  transform: translateY(-1px); box-shadow: 0 6px 18px var(--color-primary-glow);
  background: linear-gradient(135deg, var(--color-primary-dark), #1e40af);
}
.cnf9mc { width: 100%; padding: 12px 16px; font-size: 15px; line-height: 1.5; }
.ca2zky:active { transform: scale(.96); }
.ca2zky:focus-visible{outline:none;box-shadow:0 0 0 3px rgba(37,99,235,.28)}

/* 登录后用户菜单（同样全站 header 显示） */
.cpnpqa { position: relative; }
.cu52w5 {
  display: inline-flex; align-items: center; gap: 8px; padding: 4px 10px 4px 4px;
  border-radius: var(--radius-full); border: 1px solid var(--color-border); background: var(--color-bg-card);
  color: var(--color-text); cursor: pointer; transition: all var(--transition-fast);
}
.cu52w5:hover { border-color: var(--color-primary); box-shadow: var(--shadow-sm); }
.c6vsd9 { font-size: 14px; font-weight: 600; max-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.cqhgpq { color: var(--color-text-muted); transition: transform var(--transition-fast); }
.cpnpqa.cw38ur .cqhgpq { transform: rotate(180deg); }

.crxqft {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 50%; flex: none;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: #fff; font-size: 14px; font-weight: 700;
}
.czkpjc { width: 30px; height: 30px; border-radius: 50%; object-fit: cover; }

.chu6dy {
  position: absolute; top: calc(100% + 8px); right: 0; min-width: 160px;
  background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl); padding: 6px; opacity: 0; visibility: hidden; transform: translateY(-6px);
  transition: all var(--transition-fast); z-index: 1000;
}
.cpnpqa.cw38ur .chu6dy, .chu6dy.cw38ur { opacity: 1; visibility: visible; transform: translateY(0); }
.czxv3z {
  display: block; width: 100%; text-align: left; padding: 9px 12px; border: none; background: none;
  border-radius: var(--radius-sm); color: var(--color-text); font-size: 14px; text-decoration: none; cursor: pointer;
  transition: all var(--transition-fast);
}
.czxv3z:hover { background: var(--color-bg-hover); color: var(--color-primary); }
.cecj82 { height: 1px; background: var(--color-border-light); margin: 5px 0; }
.cd8924 { color: var(--color-danger); }
.cd8924:hover { background: rgba(239,68,68,.08); color: var(--color-danger); }