/* Herramientas de estudio (calculadora, estadísticas, quizzes, flashcards, progreso, plan, newsletter).
   Usa los tokens --bf-* de futuro.css, así que hereda el modo oscuro y el claro. */
:root {
    --bt-ok: #34d399;
    --bt-bad: #f87171;
    --bt-warn: #facc15;
    --bt-radius: 18px;
}
html.theme-light body {
    --bt-ok: #047857;
    --bt-bad: #b91c1c;
    --bt-warn: #a16207;
}

.bt-page [hidden] { display: none !important; }
.bt-page { padding-bottom: 56px; }
.bt-hero { padding: 34px 0 18px; }
.bt-eyebrow {
    margin: 0 0 10px;
    font: 800 .72rem/1 var(--bf-font-mono);
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--bf-cyan);
}
.bt-hero h1 { font-size: clamp(2rem, 5.5vw, 3.3rem); margin: 0 0 12px; line-height: 1.08; }
.bt-lede { max-width: 62ch; margin: 0; color: var(--bf-muted); font-size: 1.04rem; line-height: 1.6; }

.bt-layout { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 20px; align-items: start; }
.bt-stack { display: grid; gap: 16px; }
.bt-layout--plan { grid-template-columns: minmax(0, 380px) minmax(0, 1fr); }
.bt-aside { position: sticky; top: 92px; display: grid; gap: 16px; }

.bt-card {
    padding: 22px;
    border: 1px solid var(--bf-border-strong);
    border-radius: var(--bt-radius);
    background: var(--bf-surface);
    backdrop-filter: blur(8px);
}
.bt-card h2 { margin: 0 0 4px; font-size: 1.12rem; }
.bt-card > p { margin: 0 0 14px; color: var(--bf-muted); font-size: .9rem; line-height: 1.55; }
.bt-grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(min(100%, 260px), 1fr)); }
.bt-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.bt-field { display: flex; flex-direction: column; gap: 6px; }
.bt-field label, .bt-label {
    font-size: .76rem;
    font-weight: 700;
    letter-spacing: .03em;
    color: var(--bf-muted);
    line-height: 1.3;
}
.bt-input, .bt-select, .bt-textarea {
    width: 100%;
    box-sizing: border-box;
    min-height: 44px;
    padding: 10px 13px;
    border: 1px solid var(--bf-border-strong);
    border-radius: 12px;
    background: var(--bf-surface-solid, var(--bf-surface));
    color: var(--bf-ink);
    font: 500 .98rem/1.2 var(--bf-font-body);
    transition: border-color .18s var(--bf-ease), box-shadow .18s var(--bf-ease);
}
.bt-input:focus-visible, .bt-select:focus-visible, .bt-textarea:focus-visible {
    outline: none;
    border-color: var(--bf-cyan);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--bf-cyan) 25%, transparent);
}
.bt-input.is-invalid { border-color: var(--bt-bad); background: color-mix(in srgb, var(--bt-bad) 8%, transparent); }
.bt-hint { margin: 0; min-height: 1.1em; font-size: .76rem; color: var(--bf-muted); }
.bt-hint.is-error { color: var(--bt-bad); }

.bt-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 44px;
    padding: 11px 22px;
    border: 0;
    border-radius: 999px;
    background: linear-gradient(135deg, var(--bf-brand), var(--bf-cyan));
    color: #04101c;
    font: 800 .92rem/1 var(--bf-font-body);
    text-decoration: none;
    cursor: pointer;
    transition: filter .18s var(--bf-ease), transform .18s var(--bf-ease);
}
.bt-btn:hover { filter: brightness(1.1); transform: translateY(-1px); }
.bt-btn:focus-visible, .bt-chip:focus-visible, .bt-link:focus-visible { outline: 3px solid var(--bf-cyan); outline-offset: 3px; }
.bt-btn--ghost { background: transparent; color: var(--bf-ink); border: 1px solid var(--bf-border-strong); }
.bt-btn--ghost:hover { border-color: var(--bf-cyan); filter: none; }
.bt-btn[disabled] { opacity: .45; cursor: not-allowed; transform: none; filter: none; }
.bt-actions { display: flex; flex-wrap: wrap; gap: 10px; }

.bt-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    min-height: 38px;
    padding: 7px 15px;
    border: 1px solid var(--bf-border-strong);
    border-radius: 999px;
    background: transparent;
    color: var(--bf-ink);
    font: 600 .86rem/1 var(--bf-font-body);
    cursor: pointer;
    transition: border-color .18s, background-color .18s;
}
.bt-chip:hover { border-color: var(--bf-brand); }
.bt-chip[aria-pressed="true"], .bt-chip.is-on { background: var(--bf-brand); border-color: var(--bf-brand); color: #fff; }
.bt-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.bt-link { color: var(--bf-cyan); font-weight: 700; text-decoration: none; }
.bt-link:hover { text-decoration: underline; }

.bt-note {
    margin: 0;
    padding: 12px 14px;
    border: 1px solid var(--bf-border);
    border-left: 3px solid var(--bf-cyan);
    border-radius: 10px;
    background: color-mix(in srgb, var(--bf-cyan) 6%, transparent);
    color: var(--bf-muted);
    font-size: .86rem;
    line-height: 1.55;
}
.bt-note--warn { border-left-color: var(--bt-warn); background: color-mix(in srgb, var(--bt-warn) 8%, transparent); }
.bt-note--bad { border-left-color: var(--bt-bad); background: color-mix(in srgb, var(--bt-bad) 8%, transparent); }
.bt-note strong { color: var(--bf-ink); }

.bt-stat { display: grid; gap: 2px; padding: 14px 16px; border: 1px solid var(--bf-border); border-radius: 14px; background: color-mix(in srgb, var(--bf-brand) 6%, transparent); }
.bt-stat__label { font-size: .72rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--bf-muted); }
.bt-stat__value { font: 800 1.9rem/1.1 var(--bf-font-display); color: var(--bf-ink); font-variant-numeric: tabular-nums; }
.bt-stat__sub { font-size: .78rem; color: var(--bf-muted); }
.bt-stat--main { border-color: var(--bf-cyan); background: color-mix(in srgb, var(--bf-cyan) 9%, transparent); }
.bt-stat--main .bt-stat__value { font-size: 2.5rem; color: var(--bf-cyan); }
.bt-badge { display: inline-block; margin-top: 4px; padding: 2px 10px; border-radius: 999px; font-size: .72rem; font-weight: 800; width: max-content; }
.bt-badge--ok { color: var(--bt-ok); background: color-mix(in srgb, var(--bt-ok) 14%, transparent); }
.bt-badge--bad { color: var(--bt-bad); background: color-mix(in srgb, var(--bt-bad) 14%, transparent); }
.bt-badge--warn { color: var(--bt-warn); background: color-mix(in srgb, var(--bt-warn) 14%, transparent); }

.bt-bar { position: relative; height: 10px; border-radius: 999px; background: color-mix(in srgb, var(--bf-ink) 10%, transparent); overflow: hidden; }
.bt-bar > span { position: absolute; inset: 0 auto 0 0; border-radius: inherit; background: linear-gradient(90deg, var(--bf-brand), var(--bf-cyan)); transition: width .45s var(--bf-ease); }
.bt-bar--ok > span { background: var(--bt-ok); }
.bt-bar--bad > span { background: var(--bt-bad); }

.bt-cuts { list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; }
.bt-cut__head { display: flex; justify-content: space-between; gap: 10px; font-size: .92rem; }
.bt-cut__head span { font: 700 .86rem/1.4 var(--bf-font-mono); color: var(--bf-muted); }
.bt-cut__track { position: relative; height: 12px; margin: 7px 0 6px; border-radius: 999px; background: color-mix(in srgb, var(--bf-ink) 10%, transparent); }
.bt-cut__fill { position: absolute; inset: 0 auto 0 0; border-radius: inherit; transition: width .45s var(--bf-ease); }
.bt-cut.is-ok .bt-cut__fill { background: var(--bt-ok); }
.bt-cut.is-short .bt-cut__fill { background: var(--bt-bad); }
.bt-cut__tick { position: absolute; top: -4px; bottom: -4px; width: 3px; margin-left: -1.5px; border-radius: 2px; background: var(--bf-ink); }
.bt-cut p { margin: 0; font-size: .8rem; color: var(--bf-muted); }
.bt-list { margin: 0; padding-left: 1.2em; display: grid; gap: 4px; font-size: .86rem; color: var(--bf-muted); font-variant-numeric: tabular-nums; }

.bt-quizcard { display: flex; flex-direction: column; gap: 10px; }
.bt-quizcard h2 { margin: 0; }
.bt-quizcard > p { margin: 0; }
.bt-progress { height: 8px; border-radius: 999px; background: color-mix(in srgb, var(--bf-ink) 10%, transparent); overflow: hidden; }
.bt-progress > span { display: block; height: 100%; width: 0; border-radius: inherit; background: linear-gradient(90deg, var(--bf-brand), var(--bf-cyan)); transition: width .4s var(--bf-ease); }
.bt-question { margin: 6px 0 18px; font-size: clamp(1.15rem, 2.6vw, 1.5rem); line-height: 1.4; outline: none; }
.bt-options { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.bt-option {
    display: flex; align-items: center; gap: 14px; width: 100%; min-height: 52px; padding: 12px 16px; text-align: left;
    border: 1px solid var(--bf-border-strong); border-radius: 14px; background: var(--bf-surface-solid, var(--bf-surface));
    color: var(--bf-ink); font: 600 1rem/1.4 var(--bf-font-body); cursor: pointer;
    transition: border-color .15s, background-color .15s, transform .15s;
}
.bt-option:hover:not(:disabled) { border-color: var(--bf-cyan); transform: translateY(-1px); }
.bt-option:focus-visible { outline: 3px solid var(--bf-cyan); outline-offset: 2px; }
.bt-option:disabled { cursor: default; opacity: 1; }
.bt-option__key { flex: none; display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 8px; background: color-mix(in srgb, var(--bf-ink) 10%, transparent); font: 800 .85rem/1 var(--bf-font-mono); }
.bt-option.is-correct { border-color: var(--bt-ok); background: color-mix(in srgb, var(--bt-ok) 14%, transparent); }
.bt-option.is-correct .bt-option__key { background: var(--bt-ok); color: #04101c; }
.bt-option.is-wrong { border-color: var(--bt-bad); background: color-mix(in srgb, var(--bt-bad) 14%, transparent); }
.bt-option.is-wrong .bt-option__key { background: var(--bt-bad); color: #04101c; }
.bt-feedback { margin: 16px 0 0; padding: 14px 16px; border-radius: 12px; border: 1px solid var(--bf-border); font-size: .95rem; line-height: 1.55; }
.bt-feedback p { margin: 6px 0 0; color: var(--bf-muted); }
.bt-feedback.is-correct { border-color: var(--bt-ok); background: color-mix(in srgb, var(--bt-ok) 10%, transparent); }
.bt-feedback.is-wrong { border-color: var(--bt-bad); background: color-mix(in srgb, var(--bt-bad) 10%, transparent); }
.bt-feedback__explain { margin: 10px 0 0; padding: 12px 16px; border-radius: 10px; border: 1px solid var(--bf-border); font-size: .93rem; line-height: 1.6; color: var(--bf-muted); background: color-mix(in srgb, var(--bf-accent) 6%, transparent); }
.bt-score { text-align: center; padding: 10px 0 4px; }
.bt-score strong { display: block; font: 800 clamp(3rem, 10vw, 4.6rem)/1 var(--bf-font-display); color: var(--bf-cyan); font-variant-numeric: tabular-nums; }
.bt-miss { margin: 6px 0 0; font-size: .92rem; }
.bt-card > p.bt-miss { margin: 6px 0 0; font-size: .92rem; font-weight: 600; }
.bt-card > p.bt-miss--bad { color: var(--bt-bad); }
.bt-card > p.bt-miss--ok { color: var(--bt-ok); }
.bt-flip { position: relative; display: block; width: 100%; padding: 0; border: 0; background: none; color: inherit; font: inherit; cursor: pointer; perspective: 1200px; }
.bt-flip:focus-visible { outline: 3px solid var(--bf-cyan); outline-offset: 4px; border-radius: 22px; }
.bt-flip__inner { position: relative; display: block; width: 100%; min-height: 340px; transition: transform .55s var(--bf-ease); transform-style: preserve-3d; }
.bt-flip.is-flipped .bt-flip__inner { transform: rotateY(180deg); }
.bt-flip__face {
    position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; padding: 28px; overflow: auto;
    border: 1px solid var(--bf-border-strong); border-radius: 22px; background: var(--bf-surface-solid, var(--bf-surface));
    text-align: center; white-space: pre-line; font-size: clamp(1rem, 2.4vw, 1.3rem); line-height: 1.55;
    backface-visibility: hidden; -webkit-backface-visibility: hidden;
}
.bt-flip__face--back { transform: rotateY(180deg); background: color-mix(in srgb, var(--bf-brand) 12%, var(--bf-surface-solid, var(--bf-surface))); }
.bt-flip__tag { position: absolute; top: 12px; left: 16px; font: 800 .68rem/1 var(--bf-font-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--bf-cyan); }
.bt-rate { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-top: 16px; }
.bt-rate button { display: grid; gap: 2px; min-height: 58px; padding: 10px; border: 1px solid var(--bf-border-strong); border-radius: 14px; background: var(--bf-surface-solid, var(--bf-surface)); color: var(--bf-ink); font: 800 .95rem/1.2 var(--bf-font-body); cursor: pointer; }
.bt-rate button small { font-weight: 600; font-size: .74rem; color: var(--bf-muted); }
.bt-rate button:hover { transform: translateY(-1px); }
.bt-rate button:focus-visible { outline: 3px solid var(--bf-cyan); outline-offset: 2px; }
.bt-rate [data-q="1"] { border-color: var(--bt-bad); }
.bt-rate [data-q="2"] { border-color: var(--bt-warn); }
.bt-rate [data-q="3"] { border-color: var(--bt-ok); }
@media (prefers-reduced-motion: reduce) { .bt-flip__inner { transition: none; } }
@media (max-width: 520px) { .bt-flip__inner { min-height: 300px; } .bt-rate { gap: 6px; } .bt-rate button { font-size: .85rem; } }
.bt-studied {
    display: inline-flex; align-items: center; gap: 10px; margin-top: 14px; padding: 8px 14px; cursor: pointer;
    border: 1px solid var(--bf-border-strong); border-radius: 999px; background: var(--bf-surface);
    color: var(--bf-ink); font: 600 .86rem/1.2 var(--bf-font-body);
}
.bt-studied input { width: 18px; height: 18px; margin: 0; accent-color: var(--bt-ok); cursor: pointer; }
.bt-studied:has(input:checked) { border-color: var(--bt-ok); background: color-mix(in srgb, var(--bt-ok) 12%, transparent); }
.bt-studied:has(input:focus-visible) { outline: 3px solid var(--bf-cyan); outline-offset: 2px; }
.is-studied { box-shadow: inset 0 0 0 2px color-mix(in srgb, var(--bt-ok) 50%, transparent); }
.bt-pagebar { display: grid; gap: 8px; margin: 18px 0; padding: 16px 18px; border: 1px solid var(--bf-border-strong); border-radius: 16px; background: var(--bf-surface); }
.bt-pagebar p { margin: 0; }
.bt-pagebar__text { font-size: .95rem; color: var(--bf-ink); }
.bt-topiclist { list-style: none; margin: 10px 0 0; padding: 0; display: grid; gap: 8px; }
.bt-topiclist li { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; }
.bt-table { width: 100%; border-collapse: collapse; font-size: .92rem; }
.bt-table th, .bt-table td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--bf-border); }
.bt-table th { font: 800 .72rem/1 var(--bf-font-mono); letter-spacing: .1em; text-transform: uppercase; color: var(--bf-muted); }
.bt-stats4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
@media (max-width: 880px) { .bt-stats4 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.bt-subject-row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 14px; padding: 10px 12px; border: 1px solid var(--bf-border); border-radius: 12px; }
.bt-subject-row.is-on { border-color: var(--bf-border-strong); background: color-mix(in srgb, var(--bf-brand) 6%, transparent); }
.bt-check { display: inline-flex; align-items: center; gap: 10px; cursor: pointer; font-weight: 600; }
.bt-check input { width: 18px; height: 18px; margin: 0; accent-color: var(--bf-brand); cursor: pointer; }
.bt-sem-group { display: inline-flex; gap: 6px; }
.bt-sem input { position: absolute; opacity: 0; pointer-events: none; }
.bt-sem span { display: inline-flex; padding: 6px 12px; border: 1px solid var(--bf-border-strong); border-radius: 999px; font-size: .8rem; font-weight: 700; cursor: pointer; }
.bt-sem { position: relative; }
.bt-sem input:checked + span { color: #04101c; }
.bt-sem--bien input:checked + span { background: var(--bt-ok); border-color: var(--bt-ok); }
.bt-sem--regular input:checked + span { background: var(--bt-warn); border-color: var(--bt-warn); }
.bt-sem--mal input:checked + span { background: var(--bt-bad); border-color: var(--bt-bad); }
.bt-sem input:focus-visible + span { outline: 3px solid var(--bf-cyan); outline-offset: 2px; }
.bt-range { width: 100%; accent-color: var(--bf-brand); }
.bt-mastered { margin-top: 8px; padding: 10px 14px; border: 1px solid var(--bf-border); border-radius: 12px; }
.bt-mastered summary { cursor: pointer; font-weight: 700; }
.bt-phases { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.bt-phase { display: flex; gap: 14px; align-items: flex-start; }
.bt-phase p { margin: 4px 0 0; color: var(--bf-muted); font-size: .9rem; }
.bt-phase__n { flex: none; display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: linear-gradient(135deg, var(--bf-brand), var(--bf-cyan)); color: #04101c; font: 800 .9rem/1 var(--bf-font-mono); }
.bt-week { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 8px; }
.bt-week__day { padding: 10px; border: 1px solid var(--bf-border); border-radius: 12px; background: var(--bf-surface); display: grid; gap: 6px; align-content: start; }
.bt-week__day h3 { margin: 0 0 2px; font: 800 .72rem/1 var(--bf-font-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--bf-cyan); }
.bt-week__day--rest { opacity: .75; }
.bt-block-item { display: grid; gap: 2px; padding: 8px; border-radius: 8px; background: color-mix(in srgb, var(--bf-brand) 10%, transparent); font-size: .8rem; line-height: 1.35; }
.bt-block-item strong { font-size: .84rem; }
.bt-block-item span { color: var(--bf-muted); }
.bt-block-item--sim { background: color-mix(in srgb, var(--bt-warn) 14%, transparent); }
@media (max-width: 980px) { .bt-week { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 520px) { .bt-week { grid-template-columns: 1fr; } }
.bt-route { list-style: none; margin: 10px 0 0; padding: 0; display: grid; gap: 8px; }
.bt-route li { display: grid; grid-template-columns: 130px 1fr; gap: 12px; padding: 8px 10px; border-radius: 10px; background: var(--bf-surface); border: 1px solid var(--bf-border); }
.bt-route li.is-mastered { opacity: .7; }
.bt-route__when { display: grid; font: 700 .82rem/1.3 var(--bf-font-mono); color: var(--bf-cyan); }
.bt-route__when small, .bt-route__what small { display: block; font-weight: 500; color: var(--bf-muted); font-size: .74rem; }
@media (max-width: 520px) { .bt-route li { grid-template-columns: 1fr; gap: 2px; } }
@media print {
    body:has(.bt-plan) { background: #fff !important; color: #000 !important; }
    body:has(.bt-plan) .bf-header, body:has(.bt-plan) .bf-footer, body:has(.bt-plan) .cookie-banner, body:has(.bt-plan) .bf-skip-link,
    body:has(.bt-plan) .toast-container, body:has(.bt-plan) .bt-noprint, body:has(.bt-plan) #plan-form, body:has(.bt-plan) .bt-hero { display: none !important; }
    body:has(.bt-plan) .bt-layout { display: block; }
    body:has(.bt-plan) .bt-card, body:has(.bt-plan) .bt-week__day, body:has(.bt-plan) .bt-route li, body:has(.bt-plan) .bt-block-item, body:has(.bt-plan) .bt-stat {
        background: none !important; color: #000 !important; border-color: #888 !important; box-shadow: none !important; break-inside: avoid;
    }
    body:has(.bt-plan) * { color: #000 !important; }
    body:has(.bt-plan) .bt-hbar, body:has(.bt-plan) .bt-hbar > span { background: #bbb !important; }
    body:has(.bt-plan) details:not([open]) > *:not(summary) { display: block !important; }
}
.bf-footer__news { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); gap: 16px 32px; align-items: center; max-width: 1240px; margin: 34px auto 0; padding-top: 24px; border-top: 1px solid var(--bf-border); }
.bf-footer__news-text h2 { margin: 0 0 6px; }
.bf-footer__news-text p { margin: 0; max-width: none; }
.bf-footer__news .bt-nl-status { max-width: none; }
.bt-nl { display: grid; gap: 12px; }
.bt-nl__row { display: flex; gap: 10px; align-items: flex-start; }
.bt-nl__row .bt-field { flex: 1 1 auto; }
.bt-consent { align-items: flex-start; font-weight: 500; font-size: .8rem; line-height: 1.45; color: var(--bf-muted); }
.bt-consent input { margin-top: 2px; flex: none; }
.bt-nl-status.is-ok { color: var(--bt-ok); font-weight: 700; }
.bt-nl-status.is-error { color: var(--bt-bad); font-weight: 700; }
.bt-nl-status.is-warn { color: var(--bt-warn); font-weight: 700; }
.bt-fieldset { border: 0; margin: 0; padding: 0; min-width: 0; display: grid; gap: 8px; }
.bt-chip--check { position: relative; }
.bt-chip--check input { position: absolute; opacity: 0; pointer-events: none; }
.bt-chip--check:has(input:checked) { background: var(--bf-brand); border-color: var(--bf-brand); color: #fff; }
.bt-chip--check:has(input:focus-visible) { outline: 3px solid var(--bf-cyan); outline-offset: 2px; }
@media (max-width: 680px) { .bf-footer__news { grid-template-columns: 1fr; } .bt-nl__row { flex-direction: column; } .bt-nl__row .bt-btn { width: 100%; } }
.bt-tag { display: inline-flex; padding: 6px 12px; border: 1px solid var(--bf-border-strong); border-radius: 999px; background: color-mix(in srgb, var(--bf-brand) 12%, transparent); color: var(--bf-ink); font-size: .84rem; font-weight: 600; line-height: 1.3; }
.bt-dot { display: inline-block; width: 9px; height: 9px; border-radius: 50%; }
.bt-block { margin-top: 22px; }
.bt-block h3 { margin: 0 0 8px; font: 800 .74rem/1 var(--bf-font-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--bf-cyan); }
.bt-topics { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.bt-topic { padding: 14px 16px; border: 1px solid var(--bf-border); border-radius: 14px; background: var(--bf-surface); }
.bt-topic__head { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; margin-bottom: 8px; }
.bt-topic__head span { font: 700 .82rem/1.3 var(--bf-font-mono); color: var(--bf-muted); white-space: nowrap; }
.bt-hbar { height: 12px; border-radius: 999px; background: color-mix(in srgb, var(--bf-ink) 10%, transparent); overflow: hidden; }
.bt-hbar > span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--bf-brand), var(--bf-cyan)); transition: width .5s var(--bf-ease); }
.bt-topic__meta { display: flex; flex-wrap: wrap; gap: 8px 10px; align-items: center; margin-top: 10px; }
.bt-topic__meta .bt-badge { margin-top: 0; }
.bt-trend { font-size: .78rem; font-weight: 700; color: var(--bf-muted); }
.bt-trend--up { color: var(--bt-ok); }
.bt-trend--down { color: var(--bt-bad); }
.bt-dots { display: inline-flex; gap: 3px; margin-left: auto; }
.bt-dots i { width: 9px; height: 9px; border-radius: 2px; background: color-mix(in srgb, var(--bf-ink) 14%, transparent); }
.bt-dots i.is-on { background: var(--bf-cyan); }
.bt-summary { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 0 0 16px; }
@media (max-width: 640px) { .bt-summary { grid-template-columns: 1fr; } }

.bt-empty { padding: 28px; border: 1px dashed var(--bf-border-strong); border-radius: var(--bt-radius); color: var(--bf-muted); text-align: center; }
.bt-visually-hidden { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; padding: 0; }
.bt-toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; margin: 0 0 16px; }

@media (max-width: 880px) {
    .bt-layout { grid-template-columns: 1fr; }
    .bt-aside { position: static; }
}
@media (max-width: 520px) {
    .bt-grid--2 { grid-template-columns: 1fr; }
    .bt-card { padding: 18px; }
}
@media (prefers-reduced-motion: reduce) {
    .bt-bar > span, .bt-btn, .bt-chip { transition: none; }
}