html,body{background:#fff;width:100%;min-height:100%;margin:0;padding:0;overflow-x:hidden}.v2-root{--v2-bg:#fff;--v2-surface:#f7f8f8;--v2-surface-muted:#eff2f1;--v2-text-primary:#1f2937;--v2-text-secondary:#374151;--v2-text-muted:#596273;--v2-text-faint:#616b7c;--v2-border:#e5e7eb;--v2-amber-bg:#fef3c7;--v2-amber-text:#b45309;--v2-amber-icon:#f97316;--v2-coral-bg:#faeeda;--v2-coral-text:#854f0b;--v2-red-bg:#fcebeb;--v2-red-text:#a32d2d;--v2-grade-ok:var(--v2-teal-500);--v2-grade-mid:#e07b12;--v2-grade-ng:#c9372c;--v2-r-sm:8px;--v2-r-md:12px;--v2-r-lg:14px;--v2-r-xl:18px;--v2-r-pill:999px;--v2-font-ui:-apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;--v2-font-ja:-apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic UI", "Yu Gothic", "Noto Sans JP", "Helvetica Neue", Arial, sans-serif;--v2-font-zh:"PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans SC", "Source Han Sans SC", "Arial Unicode MS", system-ui, sans-serif;--v2-type-page-title:22px;--v2-type-hub-title:20px;--v2-type-body:14px;--v2-type-caption:12px;--v2-weight-page-title:600;--v2-space-1:4px;--v2-space-2:8px;--v2-space-3:12px;--v2-space-4:16px;--v2-space-5:24px;--v2-action-height:44px;--v2-content-width:780px;font-family:var(--v2-font-ja);color:var(--v2-text-primary);background:var(--v2-bg);width:100%;max-width:none;min-height:100dvh;margin:0;line-height:1.5;overflow-x:hidden}.v2-root[data-v2-theme=green]{--v2-teal-50:#e1f5ee;--v2-teal-100:#9fe1cb;--v2-teal-200:#5dcaa5;--v2-teal-300:#3fbf98;--v2-teal-500:#0f7a5c;--v2-teal-600:#0f6e56;--v2-teal-700:#0b634e;--v2-teal-900:#04342c}.v2-root[data-v2-theme=blue]{--v2-teal-50:#eaf2ff;--v2-teal-100:#c9dcff;--v2-teal-200:#8db8f0;--v2-teal-300:#6ea2e4;--v2-teal-500:#326fc1;--v2-teal-600:#2b61aa;--v2-teal-700:#245397;--v2-teal-900:#17345f}.v2-root[data-v2-theme=purple]{--v2-teal-50:#f2eeff;--v2-teal-100:#dcd2ff;--v2-teal-200:#b7a0f2;--v2-teal-300:#967ad9;--v2-teal-500:#7457c8;--v2-teal-600:#6449b2;--v2-teal-700:#533c9b;--v2-teal-900:#2f235e}.v2-lang-root{background:var(--v2-bg);width:100%;max-width:820px;min-height:100dvh;font-family:var(--v2-font-ja);margin:0 auto}.v2-lang-root:lang(zh){font-family:var(--v2-font-zh)}.v2-lang-root .v2-root{font-family:inherit}.v2-study-book-body{width:100%;max-width:var(--v2-content-width);flex-direction:column;flex:1;margin:0 auto;padding:12px 20px 24px;display:flex}.v2-lang-root :lang(ja){font-family:var(--v2-font-ja)}.v2-lang-root :lang(zh){font-family:var(--v2-font-zh)}.v2-root *,.v2-root :before,.v2-root :after{box-sizing:border-box}.v2-root button{font-family:inherit}.v2-root :focus-visible{outline:2px solid var(--v2-teal-500);outline-offset:2px}.v2-back-button{width:40px;height:40px;color:var(--v2-text-secondary);cursor:pointer;-webkit-tap-highlight-color:transparent;background:0 0;border:none;border-radius:50%;flex:none;justify-content:center;align-items:center;padding:0;display:inline-flex}.v2-back-button:active{background:var(--v2-surface-muted)}