:root{--primary: #1d5bd8;--primary-dark: #1747a6;--border: #dfe3ea;--surface: #ffffff;--shadow-soft: 0 1px 2px rgba(28, 30, 33, 0.06), 0 8px 24px rgba(28, 30, 33, 0.08);--surface-muted: #f0f2f5;--text-main: #1c1e21;--text-muted: #5b6472;}
.fbb-wrap{--fbb-ink: #1c1e21;--fbb-dim: #5b6472;--fbb-line: #dfe3ea;--fbb-feed: #f0f2f5;--fbb-paper: #ffffff;--fbb-blue: #1d5bd8;--fbb-blue-dark: #1747a6;--fbb-blue-soft: #e7effd;--fbb-math: "Cambria Math", "STIX Two Math", "Noto Sans Math", "Segoe UI Symbol", "Segoe UI", sans-serif;color: var(--fbb-ink);}
.fbb-sr,.fbb-chip input,.fbb-seg input{position: absolute;width: 1px;height: 1px;padding: 0;margin: -1px;overflow: hidden;clip: rect(0, 0, 0, 0);white-space: nowrap;border: 0;}
.fbb-studio{display: grid;grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);margin: 1rem 0 2rem;background: var(--fbb-paper);border: 1px solid var(--fbb-line);border-radius: 12px;box-shadow: var(--shadow-soft);overflow: hidden;}
.fbb-write{padding: 1.25rem 1.35rem 1.35rem;border-right: 1px solid var(--fbb-line);}
.fbb-label{display: block;float: none;width: auto;margin: 0 0 0.45rem;padding: 0;font-size: 0.8125rem;font-weight: 700;color: var(--fbb-ink);}
.fbb-textarea{width: 100%;min-height: 10rem;padding: 0.75rem 0.85rem;font-size: 1rem;line-height: 1.5;color: var(--fbb-ink);background: var(--fbb-paper);border: 1px solid var(--fbb-line);border-radius: 8px;resize: vertical;}
.fbb-textarea:focus{outline: 2px solid var(--fbb-blue);outline-offset: 1px;border-color: var(--fbb-blue);}
.fbb-group{margin: 1rem 0 0;padding: 0;border: 0;min-width: 0;}
.fbb-chips{display: grid;grid-template-columns: repeat(2, minmax(0, 1fr));gap: 0.5rem;}
.fbb-chip{position: relative;margin: 0;}
.fbb-chip span{display: block;padding: 0.55rem 0.7rem;font-family: var(--fbb-math);font-size: 1rem;text-align: center;color: var(--fbb-ink);background: var(--fbb-feed);border: 1px solid transparent;border-radius: 8px;cursor: pointer;}
.fbb-chip span:hover{border-color: var(--fbb-blue);}
.fbb-chip input:checked+span{color: var(--fbb-blue-dark);background: var(--fbb-blue-soft);border-color: var(--fbb-blue);}
.fbb-seg{display: flex;padding: 3px;background: var(--fbb-feed);border-radius: 8px;}
.fbb-seg label{position: relative;flex: 1 1 0;margin: 0;}
.fbb-seg span{display: block;padding: 0.45rem 0.4rem;font-size: 0.8125rem;font-weight: 600;text-align: center;color: var(--fbb-dim);border-radius: 6px;cursor: pointer;}
.fbb-seg input:checked+span{color: var(--fbb-ink);background: var(--fbb-paper);box-shadow: 0 1px 3px rgba(28, 30, 33, 0.15);}
.fbb-chip input:focus-visible+span,.fbb-seg input:focus-visible+span,.fbb-btn:focus-visible,.fbb-copy:focus-visible{outline: 2px solid var(--fbb-blue);outline-offset: 2px;}
.fbb-check{display: flex;gap: 0.5rem;align-items: center;margin: 1rem 0 0;font-size: 0.875rem;cursor: pointer;}
.fbb-check input{width: 1rem;height: 1rem;accent-color: var(--fbb-blue);}
.fbb-tools{display: flex;flex-wrap: wrap;gap: 0.5rem;margin-top: 1rem;padding-top: 1rem;border-top: 1px solid var(--fbb-line);}
.fbb-btn{padding: 0.45rem 0.85rem;font-size: 0.875rem;font-weight: 600;color: var(--fbb-ink);background: var(--fbb-feed);border: 0;border-radius: 6px;cursor: pointer;}
.fbb-btn:hover{background: #e4e6eb;}
.fbb-feed{position: relative;display: flex;flex-direction: column;padding: 1.25rem 1.35rem;background: var(--fbb-feed);}
.fbb-post{background: var(--fbb-paper);border-radius: 10px;box-shadow: 0 1px 2px rgba(28, 30, 33, 0.12);}
.fbb-post-head{display: flex;align-items: center;gap: 0.6rem;padding: 0.85rem 1rem 0.5rem;}
.fbb-avatar{display: inline-flex;align-items: center;justify-content: center;flex: 0 0 2.5rem;width: 2.5rem;height: 2.5rem;font-weight: 700;color: #fff;background: var(--fbb-blue);border-radius: 50%;}
.fbb-who{display: flex;flex-direction: column;flex: 1 1 auto;min-width: 0;line-height: 1.25;}
.fbb-name{font-size: 0.9375rem;font-weight: 700;}
.fbb-when{font-size: 0.75rem;color: var(--fbb-dim);}
.fbb-copy{flex: 0 0 auto;padding: 0.45rem 0.85rem;font-size: 0.8125rem;font-weight: 700;color: #fff;background: var(--fbb-blue);border: 0;border-radius: 6px;cursor: pointer;}
.fbb-copy:hover{background: var(--fbb-blue-dark);}
.fbb-copy:disabled{opacity: 0.45;cursor: not-allowed;}
.fbb-out{min-height: 8rem;max-height: 22rem;overflow-y: auto;padding: 0.25rem 1rem 1rem;font-family: var(--fbb-math);font-size: 1.0625rem;line-height: 1.5;white-space: pre-wrap;overflow-wrap: anywhere;}
.fbb-out.is-empty{font-family: inherit;font-size: 0.9375rem;color: var(--fbb-dim);}
.fbb-post-foot{display: flex;justify-content: space-around;margin: 0 1rem;padding: 0.45rem 0;font-size: 0.8125rem;font-weight: 600;color: var(--fbb-dim);border-top: 1px solid var(--fbb-line);}
.fbb-stats{margin: 0.85rem 0 0;font-size: 0.8125rem;line-height: 1.5;color: var(--fbb-dim);}
.fbb-toast{position: absolute;right: 1.35rem;bottom: 1.25rem;padding: 0.4rem 0.8rem;font-size: 0.8125rem;font-weight: 600;color: #fff;background: var(--fbb-ink);border-radius: 6px;opacity: 0;transform: translateY(6px);transition: opacity 0.2s ease, transform 0.2s ease;pointer-events: none;}
.fbb-toast.is-on{opacity: 1;transform: translateY(0);}
.fbb-article{margin: 0 auto 2.5rem;font-size: 1.0625rem;line-height: 1.7;}
.fbb-byline{display: flex;flex-wrap: wrap;justify-content: space-between;gap: 0.35rem 1rem;margin-bottom: 1.5rem;padding: 0.6rem 0;font-size: 0.875rem;color: var(--fbb-dim);border-top: 1px solid var(--fbb-line);border-bottom: 1px solid var(--fbb-line);}
.fbb-byline a{color: var(--fbb-blue);font-weight: 600;}
.fbb-article h2{margin: 0 0 0.85rem;font-size: 1.75rem;font-weight: 800;line-height: 1.25;}
.fbb-article h3{margin: 2.25rem 0 0.75rem;font-size: 1.3125rem;font-weight: 700;}
.fbb-article h4{margin: 0 0 0.4rem;font-size: 1.0625rem;font-weight: 700;}
.fbb-lead{font-size: 1.125rem;}
.fbb-article code{padding: 0.1rem 0.35rem;font-size: 0.875em;color: var(--fbb-blue-dark);background: var(--fbb-blue-soft);border-radius: 4px;}
.fbb-glyph{font-family: var(--fbb-math);font-size: 1.125rem;white-space: nowrap;}
.fbb-scroll{overflow-x: auto;margin: 0.5rem 0 1rem;border: 1px solid var(--fbb-line);border-radius: 8px;}
.fbb-table{width: 100%;border-collapse: collapse;font-size: 0.9375rem;}
.fbb-table th{padding: 0.6rem 0.85rem;text-align: left;font-size: 0.8125rem;font-weight: 700;color: var(--fbb-dim);background: var(--fbb-feed);}
.fbb-table td{padding: 0.6rem 0.85rem;border-top: 1px solid var(--fbb-line);vertical-align: middle;}
.fbb-modes{padding-left: 1.25rem;}
.fbb-modes li{margin-bottom: 0.65rem;padding-left: 0.25rem;}
.fbb-modes li::marker{font-weight: 800;color: var(--fbb-blue);}
.fbb-cost{list-style: none;padding: 0;}
.fbb-cost li{margin-bottom: 0.75rem;padding: 0.15rem 0 0.15rem 1rem;border-left: 3px solid var(--fbb-line);}
.fbb-split{display: grid;grid-template-columns: repeat(2, minmax(0, 1fr));gap: 1rem;margin-top: 0.5rem;}
.fbb-split>div{padding: 1rem 1.15rem;background: var(--fbb-feed);border-radius: 10px;}
.fbb-split>div:first-child{background: var(--fbb-blue-soft);}
.fbb-split p{margin: 0;font-size: 0.9875rem;}
@media (max-width: 860px){.fbb-studio{grid-template-columns: minmax(0, 1fr);}.fbb-write{border-right: 0;border-bottom: 1px solid var(--fbb-line);}.fbb-split{grid-template-columns: minmax(0, 1fr);}}
@media (max-width: 420px){.fbb-chips{grid-template-columns: minmax(0, 1fr);}.fbb-seg span{font-size: 0.75rem;}.fbb-post-head{flex-wrap: wrap;}.fbb-copy{width: 100%;}.fbb-article h2{font-size: 1.5rem;}}
@media (prefers-reduced-motion: reduce){.fbb-toast{transition: none;}}