/* ============================================================
   ВКЛАДКИ В ШАПКЕ
   ============================================================ */

.site-tabs {
    display: flex;
    gap: 4px;
    padding: 3px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: 10px;
    flex-shrink: 0;
}

.site-tab {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border-radius: 7px;
    color: var(--text-dim);
    font-size: 0.9rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s ease;
    background: transparent;
    border: none;
}

.site-tab:hover {
    color: var(--text);
    background: rgba(255, 255, 255, 0.04);
}

.site-tab--active {
    background: rgba(79, 172, 254, 0.15);
    color: var(--accent);
    box-shadow: inset 0 0 0 1px rgba(79, 172, 254, 0.3);
}

.site-tab__icon {
    font-size: 1rem;
    line-height: 1;
}

/* ============================================================
   СТРАНИЦА «ЗАДАЧИ» — список
   ============================================================ */

.tasks {
    position: relative;
    z-index: 1;
}

.tasks-page {
    max-width: 1000px;
    margin: 0 auto;
    padding: 48px 32px 80px;
    animation: fadeIn 0.5s ease;
}

/* --- Интро --- */
.tasks-intro {
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}

.tasks-intro__label {
    display: inline-block;
    font-size: 0.7rem;
    letter-spacing: 3px;
    color: var(--accent-3);
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 16px;
    padding: 5px 12px;
    background: rgba(167, 139, 250, 0.1);
    border: 1px solid rgba(167, 139, 250, 0.3);
    border-radius: 6px;
}

.tasks-intro__title {
    font-size: clamp(1.7rem, 3.5vw, 2.2rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.6px;
    color: var(--text);
    margin-bottom: 12px;
}

.tasks-intro__desc {
    font-size: 1rem;
    color: var(--text-dim);
    line-height: 1.6;
    max-width: 620px;
}

/* --- Фильтры --- */
.tasks-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border);
}

.tasks-filter {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 30px;
    color: var(--text-dim);
    font-size: 0.875rem;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.tasks-filter:hover {
    background: rgba(79, 172, 254, 0.12);
    border-color: var(--accent);
    color: var(--text);
}

.tasks-filter--active {
    background: rgba(79, 172, 254, 0.2);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

.tasks-filter__count {
    padding: 1px 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent);
}

.tasks-filter--active .tasks-filter__count {
    background: rgba(79, 172, 254, 0.4);
    color: #fff;
}

/* --- Список задач --- */
.tasks-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.task-item {
    display: block;
    padding: 20px 24px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text);
    cursor: pointer;
    transition: all 0.25s ease;
}

.task-item:hover {
    background: rgba(167, 139, 250, 0.08);
    border-color: var(--accent-3);
    transform: translateX(6px);
}

.task-item__meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    font-size: 0.8rem;
    color: var(--text-mute);
}

.task-item__level {
    padding: 2px 10px;
    background: rgba(167, 139, 250, 0.15);
    border: 1px solid rgba(167, 139, 250, 0.3);
    border-radius: 20px;
    color: var(--accent-3);
    font-weight: 600;
    font-size: 0.75rem;
}

.task-item__category {
    color: var(--accent);
    font-weight: 500;
}

.task-item__topic {
    color: var(--text-dim);
}

.task-item__task {
    font-size: 1rem;
    line-height: 1.55;
    color: var(--text);
    margin-bottom: 10px;
}

.task-item__arrow {
    color: var(--text-mute);
    font-size: 0.85rem;
    transition: color 0.2s;
}

.task-item:hover .task-item__arrow {
    color: var(--accent-3);
}

/* --- Пустой список --- */
.tasks-empty {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-mute);
}

.tasks-empty__icon {
    font-size: 3rem;
    margin-bottom: 16px;
    opacity: 0.6;
}

/* ============================================================
   СТРАНИЦА ОДНОЙ ЗАДАЧИ
   ============================================================ */

.task-view {
    position: relative;
    z-index: 1;
}

.task-view-inner {
    max-width: 900px;
    margin: 0 auto;
    padding: 32px 32px 80px;
    animation: fadeIn 0.4s ease;
}

.task-view__back {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 30px;
    color: var(--text-dim);
    font-size: 0.9rem;
    font-family: inherit;
    cursor: pointer;
    margin-bottom: 32px;
    transition: all 0.2s ease;
}

.task-view__back:hover {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent-3);
    color: #fff;
}

.task-view__header {
    margin-bottom: 24px;
}

.task-view__badges {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.task-view__badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.task-view__badge--level {
    background: rgba(167, 139, 250, 0.15);
    border: 1px solid rgba(167, 139, 250, 0.4);
    color: var(--accent-3);
}

.task-view__badge--category {
    background: rgba(79, 172, 254, 0.15);
    border: 1px solid rgba(79, 172, 254, 0.4);
    color: var(--accent);
}

.task-view__badge--topic {
    background: rgba(0, 242, 254, 0.1);
    border: 1px solid rgba(0, 242, 254, 0.3);
    color: var(--accent-2);
}

.task-view__task {
    font-size: 1.35rem;
    line-height: 1.5;
    color: var(--text);
    font-weight: 500;
    letter-spacing: -0.2px;
}

/* Блоки задачи */
.task-block {
    margin-top: 20px;
    padding: 20px 24px;
    border-radius: var(--radius-md);
    border-left: 4px solid;
}

.task-block__label {
    font-size: 0.75rem;
    letter-spacing: 2px;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.task-block__body {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text);
    white-space: pre-line;
}

.task-block--given {
    background: rgba(79, 172, 254, 0.06);
    border-color: var(--accent);
}

.task-block--given .task-block__label {
    color: var(--accent);
}

.task-block--solution {
    background: rgba(0, 242, 254, 0.06);
    border-color: var(--accent-2);
}

.task-block--solution .task-block__label {
    color: var(--accent-2);
}

.task-block--answer {
    background: rgba(167, 139, 250, 0.08);
    border-color: var(--accent-3);
}

.task-block--answer .task-block__label {
    color: var(--accent-3);
}

.task-block--answer .task-block__body {
    font-weight: 700;
    color: #fff;
    font-size: 1.1rem;
}

/* ============================================================
   АДАПТИВ
   ============================================================ */

@media (max-width: 900px) {
    .site-tab__text {
        display: none;
    }

    .site-tab {
        padding: 8px 12px;
    }

    .site-tab__icon {
        font-size: 1.1rem;
    }
}

@media (max-width: 700px) {
    .site-tabs {
        order: 4;
        flex-basis: 100%;
        justify-content: center;
        margin-top: 4px;
    }

    .site-tab__text {
        display: inline;
    }

    .tasks-page,
    .task-view-inner {
        padding: 28px 16px 60px;
    }

    .tasks-filters {
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: 12px;
        -webkit-overflow-scrolling: touch;
    }

    .tasks-filter {
        padding: 6px 12px;
        font-size: 0.8rem;
        flex-shrink: 0;
    }

    .task-item {
        padding: 16px 18px;
    }

    .task-item:hover {
        transform: none;
    }

    .task-view__task {
        font-size: 1.15rem;
    }

    .task-block {
        padding: 16px 18px;
    }
}
/* ============================================================
   КНОПКИ ДЕЙСТВИЙ В ЗАДАЧЕ
   ============================================================ */

.task-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 24px;
}

.task-action {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 22px;
    border-radius: 12px;
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid;
}

.task-action--hint {
    background: rgba(255, 184, 77, 0.12);
    border-color: rgba(255, 184, 77, 0.4);
    color: #ffb84d;
}

.task-action--hint:hover {
    background: rgba(255, 184, 77, 0.22);
    color: #fff;
}

.task-action--hint.task-action--active {
    background: rgba(255, 184, 77, 0.25);
    color: #fff;
}

.task-action--solve {
    background: rgba(79, 172, 254, 0.12);
    border-color: rgba(79, 172, 254, 0.4);
    color: #4facfe;
}

.task-action--solve:hover:not(:disabled) {
    background: rgba(79, 172, 254, 0.22);
    color: #fff;
}

.task-action--solve:disabled {
    opacity: 0.6;
    cursor: default;
}

.task-action--solve.task-action--done {
    background: rgba(74, 222, 128, 0.15);
    border-color: rgba(74, 222, 128, 0.5);
    color: #4ade80;
}

/* ============================================================
   БЛОК ПОДСКАЗКИ
   ============================================================ */

.task-hint {
    margin-top: 20px;
    padding: 18px 22px;
    background: rgba(255, 184, 77, 0.08);
    border-left: 4px solid #ffb84d;
    border-radius: var(--radius-md);
    animation: fadeIn 0.3s ease;
}

.task-hint__label {
    font-size: 0.8rem;
    letter-spacing: 2px;
    font-weight: 700;
    color: #ffb84d;
    margin-bottom: 10px;
}

.task-hint__body {
    font-size: 1rem;
    line-height: 1.65;
    color: var(--text);
}

/* ============================================================
   ПОЛЕ ВВОДА ОТВЕТА
   ============================================================ */

.task-answer-input {
    margin-top: 24px;
    padding: 20px 24px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
}

.task-answer-input__label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-dim);
    margin-bottom: 12px;
}

.task-answer-input__unit {
    color: var(--accent-3);
    font-weight: 400;
    font-size: 0.85rem;
}

.task-answer-input__row {
    display: flex;
    gap: 10px;
}

.task-answer-input__field {
    flex: 1;
    padding: 12px 16px;
    background: rgba(0, 0, 0, 0.25);
    border: 2px solid var(--border);
    border-radius: 10px;
    color: var(--text);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    transition: all 0.2s ease;
}

.task-answer-input__field::placeholder {
    color: var(--text-mute);
}

.task-answer-input__field:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.15);
}

.task-answer-input__btn {
    padding: 12px 24px;
    background: linear-gradient(135deg, rgba(79,172,254,0.8), rgba(167,139,250,0.8));
    border: none;
    border-radius: 10px;
    color: #fff;
    font-family: inherit;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.task-answer-input__btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(79, 172, 254, 0.3);
}

.task-answer-input__result {
    margin-top: 14px;
    padding: 12px 16px;
    border-radius: 10px;
    font-weight: 500;
    line-height: 1.5;
    animation: fadeIn 0.3s ease;
}

.task-answer-input__result--ok {
    background: rgba(74, 222, 128, 0.15);
    border-left: 4px solid #4ade80;
    color: #4ade80;
}

.task-answer-input__result--fail {
    background: rgba(255, 107, 107, 0.15);
    border-left: 4px solid #ff6b6b;
    color: #ff8080;
}

.task-answer-input__result--warn {
    background: rgba(255, 184, 77, 0.15);
    border-left: 4px solid #ffb84d;
    color: #ffb84d;
}

/* ============================================================
   БЛОК РЕШЕНИЯ (появляется по кнопке)
   ============================================================ */

.task-solution {
    margin-top: 20px;
    animation: fadeIn 0.3s ease;
}

.task-solution .task-block {
    margin-top: 16px;
}

/* ============================================================
   АДАПТИВ
   ============================================================ */

@media (max-width: 600px) {
    .task-actions {
        flex-direction: column;
    }

    .task-action {
        justify-content: center;
    }

    .task-answer-input__row {
        flex-direction: column;
    }

    .task-answer-input__btn {
        width: 100%;
    }
}