.site{flex-direction:column;min-height:100vh;display:flex}.site-main{flex:1}.site-header{z-index:20;border-bottom:1px solid var(--color-line);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);background:#fffffff0;position:sticky;top:0}.site-header__inner{align-items:center;gap:20px;max-width:1160px;margin:0 auto;padding:10px 20px;display:flex}.brand{flex:none;align-items:center;gap:8px;text-decoration:none;display:flex}.brand__mark{mix-blend-mode:multiply;width:68px;height:45px}.brand__text{display:grid}.brand__name{letter-spacing:.12em;align-items:center;gap:6px;font-size:24px;font-weight:800;line-height:1.05;display:flex}.brand__seal{background:var(--color-accent);color:var(--color-accent-ink);font-family:var(--font-hanzi);letter-spacing:0;writing-mode:vertical-rl;border-radius:3px;padding:2px 3px;font-size:10px;font-weight:400;line-height:1.15}.brand__tagline{color:var(--color-ink);letter-spacing:.3em;text-transform:uppercase;white-space:nowrap;font-size:8.5px;font-weight:700}.site-nav{flex:1;justify-content:center;align-items:center;gap:4px;display:flex}.site-nav__link{white-space:nowrap;border-radius:999px;padding:8px 12px;font-size:15px;font-weight:600;text-decoration:none}.site-nav__link:hover{color:var(--color-accent)}.site-nav__link.active{font-weight:800}.site-nav__actions{align-items:center;gap:14px;margin-left:auto;display:flex}.site-nav__login{white-space:nowrap;font-size:15px;font-weight:700;text-decoration:none}.site-nav__login:hover{color:var(--color-accent)}.site-header__tools{flex:none;align-items:center;gap:8px;display:flex}.lang{position:relative}.lang summary{cursor:pointer;border-radius:999px;align-items:center;gap:6px;padding:8px 10px;font-size:14px;font-weight:700;list-style:none;display:flex}.lang summary::-webkit-details-marker{display:none}.lang summary:after{content:"";border-bottom:2px solid;border-right:2px solid;width:6px;height:6px;transform:translateY(-2px)rotate(45deg)}.lang summary:hover{background:var(--color-surface)}.lang__menu{border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-card);min-width:170px;box-shadow:var(--shadow);padding:6px;display:grid;position:absolute;top:calc(100% + 6px);right:0}.lang__item{color:var(--color-ink);font:inherit;text-align:left;cursor:pointer;background:0 0;border:0;border-radius:8px;gap:10px;padding:9px 10px;font-size:14px;display:flex}.lang__item:hover{background:var(--color-surface)}.lang__item--active{color:var(--color-accent)}.burger{cursor:pointer;background:0 0;border:0;border-radius:10px;flex-direction:column;justify-content:center;gap:5px;width:42px;height:42px;padding:0 10px;display:none}.burger span{background:var(--color-accent);border-radius:2px;height:2px}.site-footer{border-top:1px solid var(--color-line);background:var(--color-card)}.site-footer__inner{max-width:1160px;color:var(--color-muted);flex-wrap:wrap;justify-content:space-between;gap:24px 48px;margin:0 auto;padding:32px 20px;font-size:14px;display:flex}.site-footer__inner strong{color:var(--color-ink);letter-spacing:.08em;font-size:18px}.site-footer__links{flex-wrap:wrap;align-content:flex-start;gap:8px 20px;max-width:420px;display:flex}.site-footer__links a{text-decoration:none}.site-footer__links a:hover{color:var(--color-accent)}.site-footer__label{width:100%;color:var(--color-ink);font-weight:700}@media (width<=1040px){.burger{display:flex}.site-header__inner{justify-content:space-between}.site-nav{border-bottom:1px solid var(--color-line);background:var(--color-card);box-shadow:var(--shadow);flex-direction:column;align-items:stretch;gap:0;padding:8px 20px 20px;display:none;position:absolute;top:100%;left:0;right:0}.site-nav--open{display:flex}.site-nav__link{border-bottom:1px solid var(--color-line);border-radius:0;padding:14px 4px;font-size:17px}.site-nav__actions{text-align:center;flex-direction:column;align-items:stretch;gap:12px;margin:16px 0 0}.site-nav__actions .button{min-height:48px;font-size:16px}}@media (width<=520px){.site-header__inner{padding:8px 16px}.brand__mark{width:54px;height:36px}.brand__name{font-size:20px}.brand__tagline{font-size:7px}}:root{--color-bg:#faf9f7;--color-card:#fff;--color-surface:#f4f2ee;--color-line:#e7e3dc;--color-ink:#141414;--color-muted:#6b6762;--color-accent:#d92b1f;--color-accent-dark:#b81f14;--color-accent-soft:#fdecea;--color-accent-ink:#fff;--color-ok:#1f8a4c;--tone-1:#2563eb;--tone-2:#15803d;--tone-3:#b45309;--tone-4:#7c3aed;--tone-0:#6b7280;--radius:18px;--radius-sm:12px;--shadow:0 1px 2px #1414140a, 0 10px 30px #1414140f;--font-ui:"Manrope", system-ui, -apple-system, "Segoe UI", sans-serif;--font-hanzi:"PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif}*{box-sizing:border-box}body{background:var(--color-bg);min-height:100vh;color:var(--color-ink);font-family:var(--font-ui);-webkit-font-smoothing:antialiased;margin:0;line-height:1.45}a{color:inherit}h1,h2,h3,p{margin:0}.page{width:100%;max-width:1160px;margin:0 auto;padding:32px 20px 64px}.card{border:1px solid var(--color-line);border-radius:var(--radius);background:var(--color-card);box-shadow:var(--shadow)}.eyebrow{color:var(--color-accent);letter-spacing:.14em;text-transform:uppercase;font-size:12px;font-weight:700;text-decoration:none}.button{border:1px solid var(--color-line);background:var(--color-card);min-height:46px;color:var(--color-ink);font:inherit;cursor:pointer;border-radius:999px;justify-content:center;align-items:center;gap:8px;padding:0 22px;font-weight:700;text-decoration:none;transition:background .15s,border-color .15s,transform .1s;display:inline-flex}.button:hover:not(:disabled){border-color:var(--color-ink)}.button:active:not(:disabled){transform:translateY(1px)}.button:disabled{opacity:.45;cursor:default}.button--primary{border-color:var(--color-accent);background:var(--color-accent);color:var(--color-accent-ink)}.button--primary:hover:not(:disabled){border-color:var(--color-accent-dark);background:var(--color-accent-dark)}.button--small{min-height:38px;padding:0 16px;font-size:14px}.icon-button{border:1px solid var(--color-line);background:var(--color-card);width:40px;height:40px;color:var(--color-ink);cursor:pointer;border-radius:50%;place-items:center;display:inline-grid}.icon-button:hover:not(:disabled){border-color:var(--color-ink)}.icon-button:disabled{opacity:.35;cursor:default}.tone-1{color:var(--tone-1)}.tone-2{color:var(--tone-2)}.tone-3{color:var(--tone-3)}.tone-4{color:var(--tone-4)}.tone-0{color:var(--tone-0)}.practice__head{margin-bottom:24px}.practice__title{margin:6px 0 8px;font-size:clamp(28px,5vw,40px);font-weight:800;line-height:1.1}.practice__lead{max-width:640px;color:var(--color-muted);font-size:17px}.practice__strip{scrollbar-width:none;gap:8px;margin:0 -20px 24px;padding:4px 20px;display:flex;overflow-x:auto}.practice__strip::-webkit-scrollbar{display:none}.strip-item{border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-card);min-width:64px;color:var(--color-ink);font:inherit;cursor:pointer;flex:none;justify-items:center;gap:2px;padding:8px 14px;display:grid}.strip-item:disabled{opacity:.5;cursor:default}.strip-item__hanzi{font-family:var(--font-hanzi);font-size:22px;line-height:1.2}.strip-item__pinyin{color:var(--color-muted);white-space:nowrap;font-size:12px;font-weight:600}.strip-item--active{border-color:var(--color-accent);background:var(--color-accent);color:var(--color-accent-ink)}.strip-item--active .strip-item__pinyin{color:#ffffffd9}.practice__grid{grid-template-columns:minmax(0,1fr) 340px;align-items:start;gap:24px;display:grid}.practice__side{gap:24px;display:grid}.panel{padding:24px}.panel__title{margin-bottom:14px;font-size:16px;font-weight:800}.stepper{color:var(--color-muted);justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px;font-size:14px;font-weight:600;display:flex}.stepper__buttons{gap:8px;display:flex}.example{justify-content:space-between;align-items:flex-start;gap:12px;display:flex}.example__hanzi{font-family:var(--font-hanzi);font-size:22px}.example__pinyin{font-weight:600}.example__meaning{color:var(--color-muted)}.note{color:var(--color-muted);font-size:13px}.visually-hidden{clip-path:inset(50%);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}@media (width<=900px){.practice__grid{grid-template-columns:minmax(0,1fr)}}@media (width<=520px){.page{padding:24px 16px 48px}.practice__strip{margin:0 -16px 20px;padding:4px 16px}.panel{padding:18px}}