/* Manipulative Task — IWB instructional card for a hands-on activity
 * pupils do at their seat with concrete materials (counters, fraction
 * strips, real coins). Layered on top of
 * activities/maths/shared/css/maths-activity.css for the colour/
 * typography tokens. No interactivity; render once and stay still. */

/* Defeat min-height: 100vh inherited from activity-common.css; the
 * lesson hosts this widget in a self-sizing iframe (activity-core's
 * activityHeight + display-resize's contentResize), and 100vh on body
 * makes scrollHeight chase the iframe viewport forever. Same fix as
 * worked-example.css. */
body.manipulative-task-activity,
.manipulative-task-activity .activity-container {
    min-height: 0;
}

.maths-activity.manipulative-task-activity {
    background: var(--maths-bg);
    color: var(--maths-ink);
}

.mt-card {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0.85rem 1rem 1.1rem;
}

/* ----- Header (kind pill + title) ----- */
.mt-info {
    background: var(--maths-surface);
    border: 1px solid var(--maths-border);
    border-radius: 10px;
    padding: 0.7rem 0.95rem;
    margin-bottom: 0.85rem;
}

.mt-info-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 0.3rem;
}

.mt-kind {
    font-size: 0.7rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: 0.2rem 0.6rem;
}

.mt-title {
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--maths-ink);
    margin: 0;
    line-height: 1.2;
}

/* ----- Section blocks (Materials / Instructions / Differentiation) ----- */
.mt-section {
    background: var(--maths-surface);
    border: 1px solid var(--maths-border);
    border-radius: 10px;
    padding: 0.85rem 1rem;
    margin-bottom: 0.85rem;
}

.mt-section[hidden] { display: none; }

.mt-section-heading {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--maths-ink-muted);
    margin: 0 0 0.55rem 0;
}

/* ----- Materials chips ----- */
.mt-chips {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
}

.mt-chip {
    background: var(--maths-surface-alt);
    color: var(--maths-ink);
    border: 1px solid var(--maths-border);
    border-radius: 999px;
    padding: 0.3rem 0.75rem;
    font-size: 0.95rem;
    font-weight: 600;
    line-height: 1.2;
}

/* ----- Instructions numbered list ----- */
.mt-steps {
    list-style: none;
    counter-reset: mt-step-counter;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.55rem;
}

.mt-step {
    counter-increment: mt-step-counter;
    position: relative;
    padding: 0.55rem 0.75rem 0.55rem 2.7rem;
    background: var(--maths-bg);
    border: 1px solid var(--maths-border);
    border-radius: 8px;
    font-size: 1.05rem;
    line-height: 1.4;
    color: var(--maths-ink);
}

.mt-step::before {
    content: counter(mt-step-counter);
    position: absolute;
    left: 0.55rem;
    top: 50%;
    transform: translateY(-50%);
    width: 1.7rem;
    height: 1.7rem;
    border-radius: 50%;
    background: var(--maths-primary);
    color: #fff;
    font-weight: 800;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ----- Differentiation 3-tier strip ----- */
.mt-tiers {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.65rem;
}

.mt-tier {
    border-radius: 8px;
    padding: 0.6rem 0.8rem;
    border: 1px solid var(--maths-border);
    background: var(--maths-bg);
}

.mt-tier--easier  { border-left: 4px solid var(--maths-success); }
.mt-tier--core    { border-left: 4px solid var(--maths-primary); }
.mt-tier--stretch { border-left: 4px solid var(--maths-accent); }

.mt-tier-label {
    font-size: 0.72rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--maths-ink-muted);
    margin-bottom: 0.25rem;
}

.mt-tier-body {
    margin: 0;
    font-size: 0.98rem;
    line-height: 1.4;
    color: var(--maths-ink);
}

/* ----- Empty state ----- */
.mt-empty {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--maths-ink-muted);
    font-style: italic;
    padding: 0.75rem 0;
}

.mt-empty[hidden] { display: none; }

/* ----- Display-mode (read-only IWB snapshot) compactions ----- */
body.display-mode .mt-card {
    padding: 0.5rem 0.75rem 0.75rem;
}

body.display-mode .mt-info,
body.display-mode .mt-section {
    padding: 0.55rem 0.75rem;
    margin-bottom: 0.55rem;
}

body.display-mode .mt-title {
    font-size: 1.15rem;
}