/*
 * fraction-strips — stack of horizontal strips divided into equal parts.
 * Click a segment to toggle shading. Strips line up so equivalent
 * fractions look the same length (1/2 == 2/4 == 4/8). Teaches
 * comparing, ordering, and finding equivalent fractions.
 */

.maths-activity .fs-strips {
    display: flex;
    flex-direction: column;
    gap: 0.625rem;
    background: #fffaf0;
    border: 1px solid var(--maths-border, #e0e7ef);
    border-radius: 14px;
    padding: 1rem 1.125rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 10px rgba(20, 40, 80, 0.05);
}

.maths-activity .fs-strip-row {
    display: grid;
    grid-template-columns: 84px 1fr 110px;
    align-items: center;
    gap: 0.875rem;
}

.maths-activity .fs-strip-label {
    font-weight: 800;
    color: var(--maths-primary-dark, #1b5e20);
    font-size: 1.05rem;
    text-align: right;
}

.maths-activity .fs-strip-label .fs-strip-frac {
    display: inline-block;
    font-size: 0.95rem;
}

.maths-activity .fs-strip-label sup,
.maths-activity .fs-strip-label sub { font-size: 0.65em; font-weight: 700; }
.maths-activity .fs-strip-label sup { vertical-align: 0.55em; }
.maths-activity .fs-strip-label sub { vertical-align: -0.3em; }

.maths-activity .fs-strip {
    display: flex;
    height: 38px;
    width: 100%;
    border: 3px solid #1b5e20;
    border-radius: 4px;
    overflow: hidden;
    background: #fff;
}

.maths-activity .fs-segment {
    flex: 1 1 0;
    border-right: 2.5px solid #1b5e20;
    background: #fff;
    cursor: pointer;
    transition: background-color 140ms ease-out;
}

.maths-activity .fs-segment:last-child { border-right: none; }
.maths-activity .fs-segment:hover { background: #ffe9c4; }
.maths-activity .fs-segment.fs-shaded { background: #d84315; border-right-color: #fff; }
.maths-activity .fs-segment.fs-shaded:hover { background: #bf360c; }

.maths-activity .fs-strip-readout {
    font-weight: 700;
    color: var(--maths-text, #1f2937);
    font-size: 0.95rem;
    line-height: 1.2;
    text-align: left;
}

.maths-activity .fs-strip-readout sup,
.maths-activity .fs-strip-readout sub { font-size: 0.65em; font-weight: 700; }
.maths-activity .fs-strip-readout sup { vertical-align: 0.55em; }
.maths-activity .fs-strip-readout sub { vertical-align: -0.3em; }

.maths-activity .fs-strip-readout-decimal {
    display: block;
    font-size: 0.8rem;
    color: var(--maths-text-muted, #6b7280);
    font-weight: 600;
}

.maths-activity .fs-comparison {
    background: #fff;
    border: 1px solid var(--maths-border, #e0e7ef);
    border-radius: 14px;
    padding: 0.875rem 1.125rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 8px rgba(20, 40, 80, 0.04);
}

.maths-activity .fs-comparison-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--maths-text-muted, #6b7280);
    margin-bottom: 0.25rem;
}

.maths-activity .fs-comparison-text {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--maths-primary-dark, #1b5e20);
    line-height: 1.3;
}

.maths-activity .fs-comparison-text sup,
.maths-activity .fs-comparison-text sub { font-size: 0.6em; font-weight: 700; }

.maths-activity .fs-mode-chip {
    display: inline-block;
    background: var(--maths-primary, #2E7D32);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.25rem 0.625rem;
    border-radius: 999px;
    margin-top: 0.25rem;
}

.maths-activity .fs-target-label {
    font-weight: 800;
    color: #8d4e0b;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    white-space: nowrap;
}

.maths-activity .fs-target-prompt { flex: 1; font-weight: 700; color: #1f2937; }

.maths-activity .fs-your-turn {
    margin-top: 1.25rem;
    background: #f1f8e9;
    border: 1px solid #aed581;
    border-radius: 14px;
    padding: 1rem 1.25rem;
}

.maths-activity .fs-your-turn-label {
    font-weight: 800;
    color: #33691e;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.maths-activity .fs-your-turn-list {
    margin: 0;
    padding-left: 1.25rem;
    color: #1f2937;
    font-weight: 600;
}

.maths-activity .fs-your-turn-list li { margin-bottom: 0.25rem; }

/* Display mode — hide controls, lock interaction */

body.display-mode .activity-header .controls-container,
body.display-mode .fs-target-panel,
body.display-mode .fs-your-turn { display: none !important; }

body.display-mode .fs-segment { cursor: default !important; pointer-events: none; }

@media (max-width: 720px) {
    .maths-activity .fs-strip-row { grid-template-columns: 60px 1fr 90px; gap: 0.5rem; }
    .maths-activity .fs-strip { height: 32px; }
    .maths-activity .fs-strip-readout { font-size: 0.85rem; }
}