/* Interactive labs for the Environmental Science Tutor. Uses the site's
   edu-theme design tokens so it follows light/dark automatically. */

.lab-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 32px 20px 80px;
}

.lab-container [hidden] { display: none !important; }

.lab-header {
    position: relative;
    text-align: center;
    margin-bottom: 24px;
}

.lab-back {
    display: inline-block;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.lab-back:hover { color: var(--accent-blue); }

.lab-eyebrow {
    margin: 0 0 4px;
    font-size: 0.78rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent-blue);
    font-weight: 600;
}

.lab-header h1 {
    margin: 0 0 8px;
    font-size: 2.1rem;
    color: var(--text-primary);
}

.lab-question {
    max-width: 640px;
    margin: 0 auto;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ---------- Stepper ---------- */
.lab-stepper {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-bottom: 22px;
}

.lab-step {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px 6px 6px;
    border-radius: 999px;
    border: 1px solid var(--hairline);
    background: var(--secondary-dark);
    color: var(--text-secondary);
    font: inherit;
    font-size: 0.88rem;
    cursor: pointer;
}

.lab-step:disabled { opacity: 0.45; cursor: not-allowed; }

.lab-step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--tertiary-dark);
    color: var(--text-primary);
    font-size: 0.8rem;
    font-weight: 600;
}

.lab-step-current { border-color: var(--accent-blue); color: var(--text-primary); }
.lab-step-current .lab-step-num { background: var(--accent-blue); color: #fff; }
.lab-step-done .lab-step-num { background: var(--accent-green); color: #fff; }

/* ---------- Stages ---------- */
.lab-stage {
    background: var(--secondary-dark);
    border: 1px solid var(--hairline);
    border-radius: 14px;
    padding: 22px 24px 26px;
}

.lab-stage h2 {
    margin: 0 0 14px;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.lab-stage { scroll-margin-top: 96px; }
.lab-stage h2:focus { outline: none; }

.lab-stage-body p { color: var(--text-secondary); line-height: 1.55; margin: 0 0 12px; }
.lab-scenario { font-size: 1.05rem; color: var(--text-primary) !important; }
.lab-attribution { font-size: 0.82rem; color: var(--text-muted) !important; }
.lab-caption { font-size: 0.88rem; color: var(--text-muted) !important; margin-top: 4px; }
.lab-note { font-size: 0.92rem; }

/* ---------- Buttons ---------- */
.lab-btn {
    display: inline-block;
    padding: 9px 16px;
    border-radius: 8px;
    border: 1px solid var(--hairline);
    background: var(--tertiary-dark);
    color: var(--text-primary);
    font: inherit;
    font-size: 0.95rem;
    cursor: pointer;
    text-decoration: none;
}

.lab-btn:hover:not(:disabled) { border-color: var(--accent-blue); }
.lab-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.lab-btn-primary {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: #fff;
}

.lab-link {
    background: none;
    border: none;
    color: var(--text-muted);
    text-decoration: underline;
    cursor: pointer;
    font: inherit;
    padding: 9px 6px;
}

.lab-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 10px 0; }
.lab-prompts { display: flex; flex-wrap: wrap; gap: 10px; margin: 10px 0 16px; }

/* ---------- Questions and choices ---------- */
.lab-question-card { margin: 16px 0; }
.lab-question-text { color: var(--text-primary) !important; font-weight: 600; }
.lab-choices { display: flex; flex-direction: column; gap: 8px; }

.lab-choice {
    text-align: left;
    padding: 11px 14px;
    border-radius: 10px;
    border: 1px solid var(--hairline);
    background: var(--tertiary-dark);
    color: var(--text-primary);
    font: inherit;
    cursor: pointer;
}

.lab-choice:hover:not(:disabled) { border-color: var(--accent-blue); }
.lab-choice:disabled { cursor: default; }
.lab-choice-picked { border-color: var(--accent-blue); box-shadow: 0 0 0 1px var(--accent-blue) inset; }
.lab-choice-correct { border-color: var(--accent-green); background: rgba(47, 158, 90, 0.14); }
.lab-choice-wrong { border-color: #d64545; background: rgba(214, 69, 69, 0.12); }

.lab-feedback { margin-top: 8px; font-size: 0.93rem; line-height: 1.5; }
.lab-check-card { margin-bottom: 20px; padding-bottom: 14px; border-bottom: 1px solid var(--hairline); }

.lab-result-card {
    margin: 16px 0;
    padding: 14px 16px;
    border-radius: 12px;
    border: 1px solid var(--hairline);
}

.lab-result-card h3 { margin: 0 0 6px; font-size: 1.05rem; color: var(--text-primary); }
.lab-ok { border-color: var(--accent-green); }
.lab-miss { border-color: #d6a145; }

/* ---------- Experiment panel ---------- */
.lab-panel {
    display: grid;
    grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
    gap: 22px;
    margin-top: 12px;
}

.lab-chart-wrap { width: 100%; }
.lab-canvas {
    display: block;
    width: 100%;
    height: auto;
    max-width: 100%;
    border: 1px solid var(--hairline);
    border-radius: 10px;
    background: var(--primary-dark, transparent);
}

.lab-readout { margin: 10px 0 4px; color: var(--text-primary) !important; font-size: 0.98rem; }
.lab-why { margin: 0 0 8px; font-size: 0.93rem; }

.lab-controls-col { display: flex; flex-direction: column; gap: 14px; }
.lab-control { display: flex; flex-direction: column; gap: 4px; }
.lab-control-head { display: flex; justify-content: space-between; gap: 8px; }
.lab-control-label { font-size: 0.9rem; color: var(--text-primary); }
.lab-control-value { font-size: 0.9rem; color: var(--accent-blue); font-variant-numeric: tabular-nums; }
.lab-control input[type="range"] { width: 100%; accent-color: var(--accent-blue); }
.lab-control select {
    padding: 7px 8px;
    border-radius: 8px;
    border: 1px solid var(--hairline);
    background: var(--tertiary-dark);
    color: var(--text-primary);
    font: inherit;
}
.lab-control-help { margin: 0; font-size: 0.8rem; color: var(--text-muted) !important; }
.lab-check { display: flex; gap: 6px; align-items: flex-start; color: var(--text-primary); font-size: 0.92rem; }
.lab-more { display: flex; flex-direction: column; gap: 14px; }
.lab-unlocked-note { margin: 0; font-size: 0.85rem; color: var(--accent-green) !important; }

.lab-notes { margin: 12px 0 14px; padding-left: 20px; color: var(--text-secondary); line-height: 1.55; font-size: 0.95rem; }
.lab-notes li { margin-bottom: 6px; }
.lab-stage-body h3 { margin: 18px 0 8px; font-size: 1.05rem; color: var(--text-primary); }
.lab-control-group { display: flex; flex-direction: column; gap: 8px; align-items: flex-start; }
.lab-control-group .lab-control { align-self: stretch; }
.lab-seg { display: flex; flex-wrap: wrap; gap: 6px; }
.lab-seg-btn[aria-pressed="true"] { border-color: var(--accent-blue); box-shadow: 0 0 0 1px var(--accent-blue) inset; }
.lab-number {
    width: 9rem;
    max-width: 100%;
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid var(--hairline);
    background: var(--tertiary-dark);
    color: var(--text-primary);
    font: inherit;
    font-variant-numeric: tabular-nums;
}
.lab-unit { color: var(--text-muted); font-size: 0.9rem; }
.lab-inverse { font-size: 0.9rem; }
.lab-table-wrap { max-width: 100%; overflow-x: auto; margin: 10px 0; }
.lab-table { border-collapse: collapse; width: 100%; font-size: 0.88rem; font-variant-numeric: tabular-nums; }
.lab-table caption { text-align: left; color: var(--text-muted); font-size: 0.82rem; padding-bottom: 4px; }
.lab-table th, .lab-table td { padding: 5px 8px; border-bottom: 1px solid var(--hairline); text-align: right; color: var(--text-secondary); white-space: nowrap; }
.lab-table thead th, .lab-table tbody th { text-align: left; color: var(--text-primary); font-weight: 600; }
.lab-table thead th:not(:first-child) { text-align: right; }
.lab-explore { margin-top: 14px; }
.lab-probe { min-height: 2.6em; margin: 6px 0 4px; font-size: 0.88rem; color: var(--text-secondary); font-variant-numeric: tabular-nums; }
.lab-key { display: flex; flex-wrap: wrap; gap: 4px 14px; margin: 4px 0 8px; font-size: 0.82rem; color: var(--text-muted) !important; }
.lab-key-item { display: inline-flex; align-items: center; gap: 4px; }
.lab-swatch { display: inline-block; width: 16px; height: 8px; border-radius: 2px; }
.lab-sw-recharge { background: #2f6fdd; }
.lab-sw-discharge { background: #d6892f; }
.lab-sw-shallow { background: hsl(28, 78%, 46%); }
.lab-sw-deep { background: hsl(260, 78%, 46%); }
.lab-sw-head { background: linear-gradient(90deg, rgba(47, 111, 221, 0.1), rgba(47, 111, 221, 0.55)); border: 1px solid var(--hairline); }
.lab-speed-note { margin: 0 0 8px; }
.lab-inv-cards { margin: 12px 0 18px; }

.lab-summary { color: var(--text-primary) !important; font-weight: 600; }
.lab-sr-only {
    position: absolute; width: 1px; height: 1px; overflow: hidden;
    clip: rect(0 0 0 0); white-space: nowrap;
}

/* ---------- Small screens ---------- */
@media (max-width: 820px) {
    .lab-panel { grid-template-columns: minmax(0, 1fr); }
    .lab-stage { padding: 18px 14px 22px; }
    .lab-header h1 { font-size: 1.7rem; }
    .lab-step-label { display: none; }
    .lab-step { padding: 6px; }
    .lab-step-current .lab-step-label { display: inline; }
}

@media (max-width: 560px) {
    .lab-stepper { flex-wrap: nowrap; gap: 6px; }
    .lab-step-current .lab-step-label { display: none; }
}

@media (prefers-reduced-motion: reduce) {
    .lab-choice, .lab-btn { transition: none; }
}