/* ---------- кнопки ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  min-height: var(--tap); padding: 0.55rem 1.1rem; border-radius: var(--radius-sm);
  border: 1.5px solid transparent; font: inherit; font-weight: 600; font-size: 1rem; line-height: 1.25;
  text-decoration: none; cursor: pointer; text-align: center; transition: background 0.15s, border-color 0.15s;
}
.btn[disabled] { opacity: 0.55; cursor: not-allowed; }
.btn--primary { background: var(--primary); color: var(--on-primary); }
.btn--primary:hover:not([disabled]) { background: var(--primary-hover); color: var(--on-primary); }
.btn--ghost { background: var(--surface); color: var(--primary-text); border-color: var(--border-strong); }
.btn--ghost:hover:not([disabled]) { background: var(--primary-soft); color: var(--primary-text); }
.btn--amber { background: var(--amber); color: var(--on-amber); }
.btn--amber:hover:not([disabled]) { background: var(--amber-hover); color: var(--on-amber); }
.btn--danger-ghost { background: var(--surface); color: var(--danger-text); border-color: var(--danger-border); }
.btn--danger-ghost:hover { background: var(--danger-soft); }
.btn--small { padding: 0.35rem 0.8rem; font-size: 0.95rem; }
.btn--large { padding: 0.75rem 1.5rem; font-size: 1.1rem; }
.btn--block { width: 100%; }
.btn__count { font-weight: 500; }
.nav-button { color: var(--text); }

/* ---------- формы ---------- */
.form { display: grid; gap: 1rem; }
.form-field { display: grid; gap: 0.35rem; }
.form-label { font-weight: 600; font-size: 0.95rem; }
.input, .select, .textarea {
  width: 100%; min-height: var(--tap); padding: 0.6rem 0.8rem; font: inherit; color: var(--text);
  background: var(--surface); border: 1.5px solid var(--border-strong); border-radius: var(--radius-sm);
}
.textarea { resize: vertical; min-height: 8rem; }
.input:focus, .select:focus, .textarea:focus { border-color: var(--primary); outline: 3px solid rgba(27, 95, 207, 0.25); outline-offset: 0; }
.form-field--error .input, .form-field--error .select, .form-field--error .textarea { border-color: var(--danger); }
.field-error { color: var(--danger-text); font-size: 0.9rem; min-height: 0; }
.field-error p { margin: 0; }
.field-hint { color: var(--muted); font-size: 0.9rem; margin: 0.3rem 0 0; }
.check { display: flex; gap: 0.7rem; align-items: flex-start; min-height: var(--tap); padding-block: 0.35rem; cursor: pointer; }
.check input { width: 22px; height: 22px; margin-top: 0.2rem; flex: none; accent-color: var(--primary); }
.field-row { display: flex; align-items: center; gap: 0.6rem; }
.card-form, .auth-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; box-shadow: var(--shadow); }
.auth-wrap { display: flex; justify-content: center; padding-block: 2rem 3rem; }
.auth-card { width: 100%; max-width: 440px; }
.auth-links { margin: 1rem 0 0; text-align: center; }
.auth-links a { display: inline-flex; align-items: center; min-height: var(--tap); }

/* ---------- прогресс ---------- */
.progress { display: flex; align-items: center; gap: 0.75rem; }
.progress progress {
  flex: 1; height: 10px; border: 0; border-radius: 999px; overflow: hidden; background: var(--surface-2);
  appearance: none; -webkit-appearance: none;
}
.progress progress::-webkit-progress-bar { background: var(--surface-2); border-radius: 999px; }
.progress progress::-webkit-progress-value { background: var(--success); border-radius: 999px; transition: width 0.4s; }
.progress progress::-moz-progress-bar { background: var(--success); border-radius: 999px; }
.progress__text { font-size: 0.875rem; color: var(--muted); white-space: nowrap; font-variant-numeric: tabular-nums; }

/* ---------- бейджи и статусы ---------- */
.badge { display: inline-flex; align-items: center; gap: 0.3rem; font-size: 0.8rem; font-weight: 600; padding: 0.15rem 0.6rem; border-radius: 999px; text-transform: none; letter-spacing: 0; vertical-align: middle; margin-left: 0.4rem; }
.badge--free { background: var(--success-soft); color: var(--success-text); }
.badge--premium { background: var(--amber-soft); color: var(--amber-text); }
.icon-lock { vertical-align: -3px; }
.status { display: inline-flex; align-items: center; gap: 0.3rem; padding: 0.2rem 0.7rem; border-radius: 999px; font-size: 0.875rem; font-weight: 600; white-space: nowrap; }
.status--done { background: var(--success-soft); color: var(--success-text); }
.status--progress { background: var(--amber-soft); color: var(--amber-text); }
.status--none { background: var(--surface-2); color: var(--muted); }
.status--lock { background: var(--amber-soft); color: var(--amber-text); }

/* ---------- главная ---------- */
.hero { padding-block: 2rem 2.5rem; background: linear-gradient(180deg, #eaf1fb 0%, var(--bg) 100%); }
.hero__inner { display: grid; gap: 2rem; align-items: center; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin: 1.5rem 0 0.75rem; }
.hero__note { font-size: 0.95rem; }
.hero-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; box-shadow: var(--shadow); display: grid; gap: 0.7rem; max-width: 380px; }
.hero-card__row { display: flex; gap: 0.6rem; align-items: center; font-weight: 600; }
.hero-card__dot { width: 12px; height: 12px; border-radius: 50%; flex: none; }
.hero-card__dot--blue { background: var(--primary); }
.hero-card__dot--amber { background: var(--amber); }
.hero-card__dot--mint { background: var(--success); }
.hero-card__formula { background: var(--surface-2); border-radius: var(--radius-sm); padding: 0.75rem 1rem; text-align: center; font-size: 1.3rem; }
.hero-card progress { width: 100%; height: 10px; accent-color: var(--success); }
@media (min-width: 900px) { .hero { padding-block: 4rem; } .hero__inner { grid-template-columns: 1.3fr 1fr; } .hero__card { justify-self: end; } }

.section { padding-block: 2.5rem; }
.section--tint { background: var(--surface); border-block: 1px solid var(--border); }
.section__head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 0.5rem; }
.link-arrow { font-weight: 600; display: inline-flex; align-items: center; min-height: var(--tap); }
.steps { list-style: none; padding: 0; margin: 1.25rem 0 0; display: grid; gap: 1rem; }
.step { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; }
.step h3 { margin-bottom: 0.3rem; }
.step p { margin: 0; color: var(--muted); }
.step__num { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; background: var(--primary-soft); color: var(--primary-text); font-weight: 700; margin-bottom: 0.6rem; }
@media (min-width: 768px) { .steps { grid-template-columns: repeat(3, 1fr); } }
.cta { display: flex; flex-direction: column; gap: 1rem; align-items: flex-start; background: var(--primary-soft); border-radius: var(--radius); padding: 1.5rem; }
.cta h2, .cta p { margin-bottom: 0.3rem; }
@media (min-width: 768px) { .cta { flex-direction: row; align-items: center; justify-content: space-between; } }

/* ---------- карточки ---------- */
.card-grid { list-style: none; margin: 1.25rem 0 0; padding: 0; display: grid; gap: 1rem; }
@media (min-width: 640px) { .card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .card-grid { grid-template-columns: repeat(3, 1fr); } }
.card { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; display: flex; flex-direction: column; gap: 0.4rem; transition: box-shadow 0.15s, border-color 0.15s; }
.card:hover, .card:focus-within { box-shadow: var(--shadow); border-color: var(--border-strong); }
.card__title { margin: 0; font-size: 1.25rem; }
.card__link { color: var(--text); text-decoration: none; }
.card__link::after { content: ""; position: absolute; inset: 0; border-radius: var(--radius); } /* вся карточка кликабельна */
.card__link:focus-visible { outline: none; }
.card:has(.card__link:focus-visible) { outline: 3px solid var(--focus); outline-offset: 2px; }
.card__text { margin: 0; color: var(--muted); flex: 1; }
.card__meta { margin: 0; font-size: 0.9rem; display: flex; align-items: center; gap: 0.4rem; flex-wrap: wrap; }
.card__lock { display: inline-flex; align-items: center; gap: 0.25rem; color: var(--amber-text); font-weight: 600; }

/* ---------- FAQ ---------- */
.accordion { display: grid; gap: 0.6rem; margin-top: 1.5rem; }
.accordion__item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.accordion__summary { cursor: pointer; padding: 0.85rem 3rem 0.85rem 1rem; font-weight: 600; min-height: var(--tap); list-style: none; position: relative; display: flex; align-items: center; }
.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary::after { content: "+"; position: absolute; right: 1rem; font-size: 1.5rem; color: var(--primary-text); transition: transform 0.2s; }
.accordion__item[open] .accordion__summary::after { content: "−"; }
.accordion__body { padding: 0 1rem 1rem; color: var(--text); }
.accordion__body > :last-child { margin-bottom: 0; }

/* ---------- контакты, подписка ---------- */
.contact-list { list-style: none; padding: 0; margin: 1.5rem 0; display: grid; gap: 0.6rem; }
.contact { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 0.8rem 1rem; }
.contact__label { font-size: 0.85rem; color: var(--muted); font-weight: 600; }
.contact a { min-height: 28px; word-break: break-all; }
.plans { display: grid; gap: 1rem; margin-top: 1.5rem; }
@media (min-width: 768px) { .plans { grid-template-columns: repeat(2, 1fr); } }
.plan { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.5rem; display: flex; flex-direction: column; gap: 0.75rem; }
.plan--featured { border: 2px solid var(--primary); box-shadow: var(--shadow); }
.plan__tag { margin: 0; color: var(--amber-text); font-weight: 700; font-size: 0.9rem; }
.plan__name { margin: 0; }
.plan__price { font-size: 2rem; font-weight: 700; margin: 0; }
.plan__price-note { font-size: 0.9rem; font-weight: 500; }
.plan__list { padding-left: 1.2rem; margin: 0 0 0.5rem; flex: 1; }
.plan__list li { margin-bottom: 0.4rem; }

/* ---------- обучение: страница блока ---------- */
.learn { padding-block: 1rem 3rem; }
.breadcrumbs { font-size: 0.9rem; color: var(--muted); margin-bottom: 1rem; display: flex; gap: 0.4rem; flex-wrap: wrap; }
.breadcrumbs a { display: inline-flex; align-items: center; min-height: var(--tap); }
.learn__layout { display: grid; gap: 1.5rem; align-items: start; }
@media (min-width: 960px) { .learn__layout { grid-template-columns: 300px 1fr; gap: 2.5rem; } .learn__nav { position: sticky; top: 84px; } }
.learn__nav { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.1rem; }
.learn__topic { font-size: 1.15rem; margin-bottom: 0.6rem; }
.block-list { list-style: none; padding: 0; margin: 1rem 0 0; display: grid; gap: 0.25rem; }
.block-list__link { display: flex; align-items: center; gap: 0.6rem; min-height: var(--tap); padding: 0.4rem 0.6rem; border-radius: var(--radius-sm); color: var(--text); text-decoration: none; }
.block-list__link:hover { background: var(--surface-2); color: var(--text); }
.block-list__item.is-current .block-list__link { background: var(--primary-soft); color: var(--primary-text); font-weight: 600; }
.block-list__num { flex: none; display: inline-grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; background: var(--surface-2); font-size: 0.85rem; font-weight: 700; }
.block-list__item.is-current .block-list__num { background: var(--primary); color: var(--on-primary); }
.block-list__title { flex: 1; font-size: 0.97rem; line-height: 1.35; }
.block-list__lock { color: var(--amber-text); display: inline-flex; }
.block-list__done { color: var(--success); font-weight: 700; }
.learn__hw { margin-top: 1rem; }
.learn__head h1 { margin-bottom: 1.25rem; }
.learn__main { min-width: 0; }
.pager { display: flex; justify-content: space-between; gap: 0.75rem; flex-wrap: wrap; margin-top: 2.5rem; }
.pager .btn { flex: 1 1 14rem; }
.practice { margin-top: 2.5rem; padding-top: 1.5rem; border-top: 2px dashed var(--border-strong); }
.practice__head { display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.practice__head h2 { margin: 0; }
.practice__head .progress { min-width: 220px; flex: 1; max-width: 360px; }
.invite { background: var(--primary-soft); border-radius: var(--radius); padding: 1.25rem; display: flex; flex-wrap: wrap; gap: 0.75rem; align-items: center; }
.invite h3, .invite p { flex: 1 1 100%; margin: 0; }

.lock-card { background: var(--surface); border: 1px solid var(--amber-border); border-radius: var(--radius); padding: 1.5rem; text-align: center; }
.lock-card__icon { display: inline-grid; place-items: center; width: 56px; height: 56px; border-radius: 50%; background: var(--amber-soft); color: var(--amber-text); margin-bottom: 0.75rem; }
.lock-card__icon svg { width: 28px; height: 28px; }
.lock-card__preview { color: var(--muted); max-width: 40rem; margin-inline: auto; text-align: left; position: relative; }
.lock-card__fade { color: var(--muted); }
.lock-card__actions { display: flex; flex-wrap: wrap; gap: 0.75rem; justify-content: center; }

/* ---------- проза (теория, условия, решения) ---------- */
.prose { max-width: 46rem; }
.prose > :first-child { margin-top: 0; }
.prose h2 { margin-top: 2rem; }
.prose h3 { margin-top: 1.5rem; }
.prose ul, .prose ol { padding-left: 1.4rem; }
.prose li { margin-bottom: 0.3rem; }
.prose blockquote { margin: 1rem 0; padding: 0.6rem 1rem; border-left: 4px solid var(--amber); background: var(--amber-soft); color: var(--amber-text); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
.prose blockquote > :last-child { margin-bottom: 0; }
.math--wide { display: inline-block; max-width: 100%; overflow-x: auto; overflow-y: hidden; vertical-align: bottom; padding-bottom: 0.2rem; }
.prose table, .math.block, .prose .katex-display { position: relative; } /* абсолютные части KaTeX иначе вылезают за область прокрутки и растягивают страницу на телефоне */
.prose table { display: block; overflow-x: auto; border-collapse: collapse; max-width: 100%; margin-bottom: 1rem; }
.prose th, .prose td { border: 1px solid var(--border-strong); padding: 0.45rem 0.75rem; text-align: left; }
.prose th { background: var(--surface-2); }
.prose pre { overflow-x: auto; background: var(--surface-2); padding: 0.8rem 1rem; border-radius: var(--radius-sm); }
.math.block, .prose .katex-display { overflow-x: auto; overflow-y: hidden; max-width: 100%; padding-block: 0.25rem; }
.katex { font-size: 1.08em; }
.katex-display { margin: 0.8em 0; }
.math.inline { white-space: nowrap; }

/* ---------- задачи ---------- */
.task { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius); padding: 1.1rem; margin-bottom: 1.25rem; box-shadow: var(--shadow); }
.task[data-solved="true"] { border-color: var(--success-border); }
.task__head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.5rem 0.9rem; margin-bottom: 0.6rem; }
.task__title { margin: 0; font-size: 1.1rem; }
.task__points { color: var(--muted); font-size: 0.875rem; }
.task__badge { background: var(--success-soft); color: var(--success-text); border-radius: 999px; padding: 0.1rem 0.7rem; font-size: 0.85rem; font-weight: 600; }
.task__badge[hidden] { display: none; }
.task__statement { margin-bottom: 1rem; }
.task__input { max-width: 14rem; }
.task__unit { font-weight: 600; }
.task__actions { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-top: 1rem; }
.task__actions [hidden] { display: none; }
.task__result { margin-top: 0.9rem; }
.task__result:empty { display: none; }
.result { padding: 0.7rem 1rem; border-radius: var(--radius-sm); border: 1px solid; font-weight: 600; }
.result--ok { background: var(--success-soft); border-color: var(--success-border); color: var(--success-text); }
.result--bad { background: var(--danger-soft); border-color: var(--danger-border); color: var(--danger-text); }
.result--info { background: var(--surface-2); border-color: var(--border-strong); color: var(--text); font-weight: 500; }
.task__hints { list-style: none; padding: 0; margin: 0.9rem 0 0; display: grid; gap: 0.5rem; }
.task__hints:empty { display: none; }
.hint { background: var(--amber-soft); border: 1px solid var(--amber-border); color: var(--text); border-radius: var(--radius-sm); padding: 0.6rem 1rem; }
.hint__label { display: block; font-size: 0.8rem; font-weight: 700; color: var(--amber-text); text-transform: uppercase; letter-spacing: 0.04em; }
.hint > :last-child { margin-bottom: 0; }
.task__solution { margin-top: 0.9rem; padding: 1rem; background: var(--primary-soft); border-radius: var(--radius-sm); max-width: none; }
.task__solution[hidden] { display: none; }
.task__solution > :last-child { margin-bottom: 0; }

.choices { border: 0; padding: 0; margin: 0; display: grid; gap: 0.5rem; }
.choices legend { font-weight: 600; font-size: 0.95rem; margin-bottom: 0.4rem; padding: 0; }
.choice { display: flex; align-items: center; gap: 0.75rem; min-height: var(--tap); padding: 0.45rem 0.8rem; border: 1.5px solid var(--border-strong); border-radius: var(--radius-sm); cursor: pointer; background: var(--surface); }
.choice:hover { border-color: var(--primary); background: var(--primary-soft); }
.choice:has(input:checked) { border-color: var(--primary); background: var(--primary-soft); }
.choice:has(input:focus-visible) { outline: 3px solid var(--focus); outline-offset: 2px; }
.choice input { width: 20px; height: 20px; accent-color: var(--primary); flex: none; }
.choice__num { font-weight: 700; color: var(--muted); min-width: 1.2em; }
.choice__text { flex: 1; }

.matching__cols { display: grid; gap: 1rem; margin-bottom: 1rem; }
@media (min-width: 640px) { .matching__cols { grid-template-columns: 1fr 1fr; } }
.matching__title { font-size: 0.9rem; color: var(--muted); margin: 0 0 0.4rem; text-transform: uppercase; letter-spacing: 0.04em; }
.matching__list { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.4rem; }
.matching__list li { display: flex; gap: 0.6rem; align-items: baseline; background: var(--surface-2); border-radius: var(--radius-sm); padding: 0.45rem 0.7rem; }
.matching__key { flex: none; font-weight: 700; color: var(--primary-text); min-width: 1.4em; }
.matching__answers { display: flex; flex-wrap: wrap; gap: 0.75rem; }
.matching__pick { display: flex; align-items: center; gap: 0.5rem; }
.matching__pick .select { width: 5rem; }

/* ---------- кабинет ---------- */
.stats { display: grid; gap: 0.75rem; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); margin-block: 1rem 1.5rem; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.1rem; display: flex; flex-direction: column; }
.stat__value { font-size: 1.9rem; font-weight: 700; line-height: 1.2; }
.stat__label { color: var(--muted); font-size: 0.92rem; }
.stat--sub.is-active .stat__value { color: var(--success-text); }
.section-block { margin-top: 2rem; }
.topic-rows { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.75rem; }
.topic-row { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.1rem; display: grid; gap: 0.6rem; }
.topic-row__title { font-weight: 600; font-size: 1.05rem; display: inline-flex; align-items: center; min-height: 32px; }
.topic-row__hw { text-decoration: none; color: var(--text); display: inline-flex; gap: 0.5rem; align-items: center; min-height: var(--tap); }
@media (min-width: 768px) { .topic-row { grid-template-columns: 1fr auto; align-items: center; } }
.recent { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.4rem; }
.recent__item { display: flex; gap: 0.75rem; align-items: center; flex-wrap: wrap; padding: 0.4rem 0; border-bottom: 1px solid var(--border); }
.recent__mark { flex: none; display: inline-grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; font-weight: 700; font-size: 0.85rem; }
.recent__mark.is-ok { background: var(--success-soft); color: var(--success-text); }
.recent__mark.is-bad { background: var(--danger-soft); color: var(--danger-text); }
.recent__time { margin-left: auto; font-size: 0.875rem; }

/* ---------- домашнее задание ---------- */
.hw-list { list-style: none; padding: 0; margin: 1.25rem 0 0; display: grid; gap: 0.75rem; }
.hw-item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem 1.1rem; display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; align-items: center; justify-content: space-between; }
.hw-item__title { margin: 0; font-size: 1.15rem; }
.hw-item__main p { margin: 0.2rem 0 0; }
.hw-summary { display: flex; flex-wrap: wrap; gap: 0.75rem 1.25rem; align-items: center; padding: 0.8rem 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); margin-bottom: 1.25rem; }

/* ---------- админка ---------- */
.subnav { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.25rem; }
.subnav a { display: inline-flex; align-items: center; min-height: var(--tap); padding: 0 1rem; border-radius: 999px; background: var(--surface); border: 1px solid var(--border); text-decoration: none; color: var(--text); font-weight: 500; }
.subnav a[aria-current="page"] { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.search-form { display: flex; gap: 0.5rem; margin-bottom: 1rem; max-width: 460px; }
.table-wrap { overflow-x: auto; }
.table { width: 100%; border-collapse: collapse; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.table th, .table td { text-align: left; padding: 0.65rem 0.8rem; border-bottom: 1px solid var(--border); vertical-align: top; }
.table th { background: var(--surface-2); font-size: 0.875rem; white-space: nowrap; }
.sub-form { display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center; }
.input--date { width: 11rem; }
@media (max-width: 899px) {
  .table thead { display: none; }
  .table, .table tbody, .table tr, .table td { display: block; width: 100%; }
  .table tr { border-bottom: 2px solid var(--border-strong); padding: 0.5rem 0; }
  .table td { border: 0; padding: 0.3rem 0.8rem; }
  .table td::before { content: attr(data-label) ": "; font-weight: 600; color: var(--muted); font-size: 0.85rem; }
}
.feedback-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.75rem; }
.feedback { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 1rem; }
.feedback.is-unread { border-left: 5px solid var(--primary); }
.feedback__head { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem; }
.feedback__from { color: var(--muted); font-size: 0.92rem; margin: 0.2rem 0 0.6rem; }
.feedback__text { white-space: pre-wrap; }

/* ---------- ошибки ---------- */
.error-page { text-align: center; padding-block: 3.5rem; }
.error-page__code { font-size: clamp(4rem, 18vw, 7rem); font-weight: 800; color: var(--primary); opacity: 0.18; margin: 0; line-height: 1; }
.error-page .lead { margin-inline: auto; }

span.math.block { display: block; text-align: center; }