:root{--c-brand:#b3121b;--c-brand-dark:#8c0e15;--c-brand-soft:#fdecee;--c-ink:#14161a;--c-ink-2:#4a5260;--c-ink-3:#6b7280;--c-ink-inv:#fff;--c-bg:#fff;--c-bg-soft:#f5f6f8;--c-bg-warm:#fbf9f7;--c-line:#e5e8ed;--c-line-strong:#d2d7df;--c-region:#0e5c8a;--c-region-soft:#e8f2f9;--c-live:#d92b2b;--c-guide:#0f6b4f;--c-guide-soft:#e9f5f0;--font-sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC","Noto Sans CJK SC","WenQuanYi Micro Hei",Arial,sans-serif;--font-num:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC",Arial,sans-serif;--fs-xs:12px;--fs-sm:13px;--fs-base:15px;--fs-md:16px;--fs-lg:18px;--fs-xl:22px;--fs-2xl:26px;--fs-3xl:32px;--fs-4xl:40px;--lh-tight:1.25;--lh-snug:1.4;--lh-body:1.75;--fw-normal:400;--fw-medium:500;--fw-bold:700;--fw-black:800;--w-page:1240px;--w-wide:1440px;--w-read:720px;--sp-1:4px;--sp-2:8px;--sp-3:12px;--sp-4:16px;--sp-5:20px;--sp-6:24px;--sp-7:32px;--sp-8:40px;--sp-9:48px;--sp-10:64px;--r-sm:4px;--r-md:8px;--r-lg:12px;--r-pill:999px;--sh-1:0 1px 2px rgba(16,24,40,.06);--sh-2:0 2px 8px rgba(16,24,40,.08);--sh-3:0 8px 24px rgba(16,24,40,.1);--t-fast:.15s ease;--t-base:.22s ease;--font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono","Courier New",monospace;--fs-display:64px;--lh-ui:1.6;--c-surface-dark:#1B1E24;--c-surface-header:#F8F9FB}