/* ===================================================================
   MATH LAB — Design System
   Shared variables, components, and utilities for all Math Lab tools
   =================================================================== */

/* --- CSS Custom Properties (Year-band scoped) --- */
:root {
    --lab-font-family: "Segoe UI", "Roboto", -apple-system, BlinkMacSystemFont, sans-serif;
    --lab-line-height: 1.6;
    --lab-space-xs: 4px;
    --lab-space-sm: 8px;
    --lab-space-md: 16px;
    --lab-space-lg: 24px;
    --lab-space-xl: 32px;
    --lab-space-2xl: 48px;
    --lab-space-3xl: 64px;
    --lab-radius-sm: 6px;
    --lab-radius-md: 12px;
    --lab-radius-lg: 16px;
    --lab-radius-xl: 24px;
    --lab-shadow-card: 0 2px 8px rgba(0,0,0,0.08);
    --lab-shadow-hover: 0 6px 20px rgba(0,0,0,0.12);
    --lab-shadow-active: 0 1px 4px rgba(0,0,0,0.15);
    --lab-correct: #43A047;
    --lab-correct-bg: #E8F5E9;
    --lab-wrong: #E53935;
    --lab-wrong-bg: #FFEBEE;
    --lab-hint-color: #FF8F00;
    --lab-hint-bg: #FFF8E1;
    --lab-highlight: #FDD835;
}

/* Primary band (Y2-4) */
[data-year-band="primary"] {
    --lab-primary: #4FC3F7;
    --lab-primary-dark: #0288D1;
    --lab-accent: #FFB74D;
    --lab-accent-dark: #F57C00;
    --lab-surface: #FFFFFF;
    --lab-bg: #F5F7FA;
    --lab-text: #263238;
    --lab-text-muted: #607D8B;
    --lab-font-base: 20px;
    --lab-font-sm: 16px;
    --lab-font-lg: 24px;
    --lab-font-h1: 40px;
    --lab-font-h2: 32px;
    --lab-font-h3: 24px;
}

/* Middle band (Y5-7) */
[data-year-band="middle"] {
    --lab-primary: #42A5F5;
    --lab-primary-dark: #1565C0;
    --lab-accent: #66BB6A;
    --lab-accent-dark: #2E7D32;
    --lab-surface: #FFFFFF;
    --lab-bg: #F0F4F8;
    --lab-text: #1A2A3A;
    --lab-text-muted: #546E7A;
    --lab-font-base: 18px;
    --lab-font-sm: 14px;
    --lab-font-lg: 22px;
    --lab-font-h1: 36px;
    --lab-font-h2: 28px;
    --lab-font-h3: 22px;
}

/* Senior band (Y8-10) */
[data-year-band="senior"] {
    --lab-primary: #5C6BC0;
    --lab-primary-dark: #283593;
    --lab-accent: #26A69A;
    --lab-accent-dark: #00796B;
    --lab-surface: #FFFFFF;
    --lab-bg: #ECEFF1;
    --lab-text: #1A1A2E;
    --lab-text-muted: #455A64;
    --lab-font-base: 16px;
    --lab-font-sm: 13px;
    --lab-font-lg: 20px;
    --lab-font-h1: 32px;
    --lab-font-h2: 26px;
    --lab-font-h3: 20px;
}

/* --- Base --- */
.math-lab,
.math-lab-tool {
    font-family: var(--lab-font-family);
    font-size: var(--lab-font-base, 18px);
    line-height: var(--lab-line-height);
    color: var(--lab-text, #263238);
    -webkit-font-smoothing: antialiased;
}

.math-lab *,
.math-lab-tool * {
    box-sizing: border-box;
}

/* --- Year Badge --- */
.year-badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 13px;
    font-weight: 600;
    background: #f0f0f0;
    color: #607D8B;
    border: 1px solid #ddd;
    margin: 0 2px;
    white-space: nowrap;
}
.year-badge.active,
.year-badge--active {
    background: var(--lab-primary, #42A5F5);
    color: #fff;
    border-color: var(--lab-primary, #42A5F5);
}

/* --- Buttons --- */
.lab-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: var(--lab-radius-sm);
    font-size: var(--lab-font-base, 16px);
    font-weight: 600;
    font-family: var(--lab-font-family);
    border: none;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s, box-shadow 0.2s;
    text-decoration: none;
    line-height: 1.4;
}
.lab-btn:active {
    transform: translateY(0);
    box-shadow: var(--lab-shadow-active);
}
.lab-btn-primary {
    background: var(--lab-primary, #42A5F5);
    color: #fff;
}
.lab-btn-primary:hover {
    background: var(--lab-primary-dark, #1565C0);
    transform: translateY(-1px);
    color: #fff;
    text-decoration: none;
}
.lab-btn-ghost {
    background: transparent;
    color: var(--lab-primary, #42A5F5);
    border: 2px solid var(--lab-primary, #42A5F5);
}
.lab-btn-ghost:hover {
    background: var(--lab-primary, #42A5F5);
    color: #fff;
    text-decoration: none;
}
.lab-btn-lg {
    padding: 14px 32px;
    font-size: var(--lab-font-lg, 20px);
}
.lab-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* --- Control panel shared components --- */
.lab-section-label {
    font-size: var(--lab-font-sm, 14px);
    font-weight: 700;
    color: var(--lab-text, #263238);
    margin: 12px 0 6px;
}
.lab-section-label:first-child { margin-top: 0; }
.lab-btn-row,
.lab-control-row {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    margin-bottom: 4px;
}
.lab-btn-sm {
    padding: 6px 16px;
    font-size: var(--lab-font-sm, 14px);
    background: #f0f0f0;
    color: #555;
    border: 1px solid #ddd;
    border-radius: var(--lab-radius-sm, 6px);
    cursor: pointer;
    font-family: var(--lab-font-family);
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.lab-btn-sm:hover {
    background: #e0e0e0;
}
.lab-btn-sm.active,
.lab-btn-sm.lab-btn-active {
    background: var(--lab-primary, #42A5F5);
    color: #fff;
    border-color: var(--lab-primary, #42A5F5);
}
.lab-btn-sm.active:hover,
.lab-btn-sm.lab-btn-active:hover {
    background: var(--lab-primary-dark, #1565C0);
    border-color: var(--lab-primary-dark, #1565C0);
}

/* Feedback banner (correct/wrong) */
.lab-feedback {
    margin-top: 8px;
    padding: 10px 14px;
    border-radius: var(--lab-radius-sm, 6px);
    font-size: 14px;
    line-height: 1.5;
}
.lab-feedback--correct {
    background: var(--lab-correct-bg, #E8F5E9);
    color: var(--lab-correct, #2E7D32);
    border: 1px solid #A5D6A7;
}
.lab-feedback--wrong {
    background: var(--lab-wrong-bg, #FFEBEE);
    color: var(--lab-wrong, #C62828);
    border: 1px solid #EF9A9A;
    line-height: 1.8;
}
.lab-feedback--hint {
    background: var(--lab-hint-bg, #FFF8E1);
    color: var(--lab-hint-color, #E65100);
    border: 1px solid #FFE0B2;
}

/* --- Card --- */
.lab-card {
    background: var(--lab-surface, #fff);
    border-radius: var(--lab-radius-md);
    box-shadow: var(--lab-shadow-card);
    padding: var(--lab-space-lg);
    transition: box-shadow 0.25s, transform 0.25s;
    position: relative;
    overflow: hidden;
}
.lab-card:hover {
    box-shadow: var(--lab-shadow-hover);
    transform: translateY(-2px);
}
.lab-card--bordered {
    border-left: 5px solid var(--card-accent, #42A5F5);
}
.lab-card a {
    text-decoration: none;
    color: inherit;
}

/* --- Tool header (in-tool view) --- */
.lab-tool-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--lab-space-md) var(--lab-space-lg);
    background: var(--lab-surface, #fff);
    border-bottom: 1px solid #e0e0e0;
    position: sticky;
    top: 0;
    z-index: 100;
    flex-wrap: wrap;
    gap: var(--lab-space-sm);
}
.lab-tool-header-left {
    display: flex;
    align-items: center;
    gap: var(--lab-space-sm);
}
.lab-back-link {
    color: var(--lab-text-muted, #607D8B);
    text-decoration: none;
    font-size: var(--lab-font-sm);
    font-weight: 500;
}
.lab-back-link:hover { color: var(--lab-primary); text-decoration: none; }
.lab-breadcrumb-sep { color: #ccc; }
.lab-tool-category { font-size: var(--lab-font-sm); font-weight: 600; }
.lab-tool-title { font-size: var(--lab-font-h3, 22px); font-weight: 700; margin: 0; }
.lab-tool-header-right {
    display: flex;
    align-items: center;
    gap: var(--lab-space-sm);
}

/* --- Workspace (two-column) --- */
.lab-workspace {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: var(--lab-space-lg);
    padding: var(--lab-space-lg);
    min-height: 500px;
}
.lab-controls {
    background: var(--lab-surface, #fff);
    border-radius: var(--lab-radius-md);
    padding: var(--lab-space-lg);
    box-shadow: var(--lab-shadow-card);
}
.lab-canvas {
    background: var(--lab-surface, #fff);
    border-radius: var(--lab-radius-md);
    box-shadow: var(--lab-shadow-card);
    min-height: 300px;
    max-width: 1000px;
    position: relative;
    overflow: hidden;
}

/* --- Challenge / Feedback / Hint panels --- */
.lab-panel {
    margin: 0 var(--lab-space-lg) var(--lab-space-lg);
    padding: var(--lab-space-lg);
    border-radius: var(--lab-radius-md);
    box-shadow: var(--lab-shadow-card);
    animation: labFadeIn 0.3s ease;
}
.lab-challenge-panel {
    background: #F3E5F5;
    border-left: 5px solid #AB47BC;
}
.lab-feedback-panel {
    display: flex;
    align-items: flex-start;
    gap: var(--lab-space-md);
}
.lab-feedback-panel.correct { background: var(--lab-correct-bg); border-left: 5px solid var(--lab-correct); }
.lab-feedback-panel.wrong { background: var(--lab-wrong-bg); border-left: 5px solid var(--lab-wrong); }
.lab-hint-panel {
    background: var(--lab-hint-bg);
    border-left: 5px solid var(--lab-hint-color);
    display: flex;
    align-items: flex-start;
    gap: var(--lab-space-md);
}
.lab-feedback-icon {
    font-size: 28px;
    flex-shrink: 0;
}

/* --- Info Tabs --- */
.lab-info-tabs {
    margin: 0 var(--lab-space-lg) var(--lab-space-lg);
}
.lab-tab-nav {
    display: flex;
    gap: 0;
    border-bottom: 2px solid #e0e0e0;
    margin-bottom: var(--lab-space-md);
}
.lab-tab-btn {
    padding: var(--lab-space-sm) var(--lab-space-lg);
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
    cursor: pointer;
    font-size: var(--lab-font-sm);
    font-weight: 600;
    color: var(--lab-text-muted);
    font-family: var(--lab-font-family);
    transition: color 0.2s, border-color 0.2s;
}
.lab-tab-btn:hover { color: var(--lab-text); }
.lab-tab-btn.active {
    color: var(--lab-primary);
    border-bottom-color: var(--lab-primary);
}
.lab-tab-content {
    padding: var(--lab-space-md) 0;
}

/* --- Progress stats --- */
.lab-progress-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--lab-space-md);
}
.lab-stat {
    text-align: center;
    padding: var(--lab-space-md);
    background: var(--lab-bg, #f5f7fa);
    border-radius: var(--lab-radius-sm);
}
.lab-stat-value {
    display: block;
    font-size: var(--lab-font-lg, 22px);
    font-weight: 700;
    color: var(--lab-primary);
}
.lab-stat-label {
    display: block;
    font-size: var(--lab-font-sm, 13px);
    color: var(--lab-text-muted);
    margin-top: 4px;
}

/* --- Animations --- */
@keyframes labFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes labPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(67,160,71,0.4); }
    50% { box-shadow: 0 0 0 10px rgba(67,160,71,0); }
}
@keyframes labShake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-6px); }
    40%, 80% { transform: translateX(6px); }
}
.lab-shake { animation: labShake 0.4s ease; }
.lab-pulse { animation: labPulse 0.6s ease 2; }

/* ===================================================================
   Left-panel control kit — shared component library
   Used by tools that build panels via JS with class names like
   lab-card, lab-card-label, lab-btn-group, lab-btn-pill, lab-btn-stack,
   lab-btn-stack-item, lab-stat-row, lab-slider-row, lab-input-row,
   lab-hint, lab-prompt, lab-feedback, lab-equation.
   =================================================================== */

/* Left-rail container — each tool's JS appends cards here */
.lab-controls {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding: 12px;
    background: transparent;
    box-shadow: none;
    border-radius: 0;
}

/* Card — subtle grey-blue surface, soft corners, no harsh border */
.lab-card {
    background: #FFFFFF;
    border: 1px solid #E3E8EE;
    border-radius: 12px;
    padding: 14px 16px;
    box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.lab-card-label {
    font-size: 11px;
    font-weight: 700;
    color: #64748B;
    letter-spacing: 0.6px;
    text-transform: uppercase;
    margin: 0;
}
/* Accent card for prompts/challenges — soft tint */
.lab-card-accent {
    background: linear-gradient(135deg, #F8FAFF 0%, #EEF2FF 100%);
    border-color: #C7D2FE;
}

/* Button groups — horizontal pill-row and vertical stack */
.lab-btn-group {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    align-items: stretch;
}
.lab-btn-stack {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

/* Pill button — flat, rounded, active state uses accent */
.lab-btn-pill {
    flex: 1 1 0;
    min-width: 0;
    padding: 8px 12px;
    border: 1px solid #CBD5E1;
    background: #FFFFFF;
    color: #334155;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 600;
    font-family: var(--lab-font-family);
    line-height: 1.25;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
    text-align: center;
    white-space: normal;
    word-break: break-word;
}
.lab-btn-pill:hover {
    background: #F1F5F9;
    border-color: #94A3B8;
}
.lab-btn-pill.is-active,
.lab-btn-pill.active {
    background: var(--lab-primary, #42A5F5);
    color: #FFFFFF;
    border-color: var(--lab-primary, #42A5F5);
    box-shadow: 0 1px 3px rgba(37, 99, 235, 0.25);
}
.lab-btn-pill.is-active:hover,
.lab-btn-pill.active:hover {
    background: var(--lab-primary-dark, #1565C0);
    border-color: var(--lab-primary-dark, #1565C0);
}

/* Stack button — block-style, left-aligned, full width */
.lab-btn-stack-item {
    display: block;
    width: 100%;
    padding: 10px 14px;
    border: 1px solid #CBD5E1;
    background: #FFFFFF;
    color: #334155;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 600;
    font-family: var(--lab-font-family);
    line-height: 1.3;
    text-align: left;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s, box-shadow 0.15s;
}
.lab-btn-stack-item:hover {
    background: #F1F5F9;
    border-color: #94A3B8;
}
.lab-btn-stack-item.is-active,
.lab-btn-stack-item.active {
    background: var(--lab-primary, #42A5F5);
    color: #FFFFFF;
    border-color: var(--lab-primary, #42A5F5);
    box-shadow: 0 1px 3px rgba(37, 99, 235, 0.25);
}

/* Primary action button — full-width CTA inside a card */
.lab-btn-primary {
    display: block;
    width: 100%;
    padding: 11px 16px;
    border: none;
    background: var(--lab-primary, #42A5F5);
    color: #FFFFFF;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 700;
    font-family: var(--lab-font-family);
    cursor: pointer;
    transition: background 0.15s, transform 0.1s, box-shadow 0.15s;
    box-shadow: 0 1px 2px rgba(37, 99, 235, 0.2);
}
.lab-btn-primary:hover {
    background: var(--lab-primary-dark, #1565C0);
    box-shadow: 0 3px 8px rgba(37, 99, 235, 0.25);
}
.lab-btn-primary:active { transform: translateY(1px); }
.lab-btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* Stat rows — label on the left, value on the right */
.lab-stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    padding: 6px 0;
    border-bottom: 1px dashed #E2E8F0;
    font-size: 13px;
}
.lab-stat-row:last-child { border-bottom: none; }
.lab-stat-label {
    color: #64748B;
    font-weight: 500;
}

/* Toggle row — label on the left, on/off button pinned to the right */
.lab-toggle-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    padding: 6px 0;
    font-size: 13px;
}
.lab-toggle-label {
    color: #475569;
    font-weight: 500;
    flex: 1 1 auto;
}
.lab-toggle-row > .lab-btn-pill {
    flex: 0 0 auto;
    min-width: 54px;
    text-align: center;
}
.lab-stat-val {
    color: #0F172A;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

/* Slider row — label top, range input below */
.lab-slider-row {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.lab-slider-label {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    font-size: 13px;
    font-weight: 600;
    color: #334155;
}
.lab-slider-value {
    color: var(--lab-primary, #42A5F5);
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}
.lab-slider-row input[type="range"] {
    width: 100%;
    accent-color: var(--lab-primary, #42A5F5);
    cursor: pointer;
}

/* Input rows (text + suffix label like "° cm") */
.lab-input-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 0;
}
.lab-input {
    flex: 1 1 auto;
    min-width: 0;
    padding: 8px 10px;
    border: 1px solid #CBD5E1;
    border-radius: 8px;
    font-size: 14px;
    font-family: var(--lab-font-family);
    color: #0F172A;
    background: #FFFFFF;
    transition: border-color 0.15s, box-shadow 0.15s;
}
.lab-input:focus {
    outline: none;
    border-color: var(--lab-primary, #42A5F5);
    box-shadow: 0 0 0 3px rgba(66, 165, 245, 0.15);
}
.lab-input-suffix {
    font-size: 13px;
    font-weight: 600;
    color: #64748B;
    flex-shrink: 0;
}

/* Prompt text — bigger and bold for challenge question */
.lab-prompt {
    font-size: 14px;
    font-weight: 600;
    color: #1E293B;
    line-height: 1.5;
    margin: 0;
}

/* Hint — soft amber callout */
.lab-hint {
    font-size: 12.5px;
    line-height: 1.5;
    color: #92400E;
    background: #FFFBEB;
    border: 1px solid #FDE68A;
    border-radius: 8px;
    padding: 8px 10px;
}

/* Feedback banner inside a challenge card */
.lab-feedback {
    font-size: 13px;
    font-weight: 600;
    line-height: 1.5;
    padding: 10px 12px;
    border-radius: 8px;
    border: 1px solid transparent;
}
.lab-feedback.is-correct,
.lab-feedback--correct {
    background: #ECFDF5;
    color: #065F46;
    border-color: #A7F3D0;
}
.lab-feedback.is-wrong,
.lab-feedback--wrong {
    background: #FEF2F2;
    color: #991B1B;
    border-color: #FECACA;
}

/* Equation block (e.g. a²+b²=c²) */
.lab-equation {
    font-family: "Cambria Math", "Georgia", serif;
    font-size: 18px;
    font-weight: 600;
    color: #0F172A;
    text-align: center;
    padding: 10px 6px;
    background: #F8FAFC;
    border-radius: 8px;
}

/* Formula block — live formula with substituted values (used in SA/V lab) */
.lab-formula {
    padding: 8px 10px;
    background: #F1F5F9;
    border: 1px solid #E2E8F0;
    border-radius: 8px;
    margin-top: 6px;
}
.lab-formula + .lab-formula {
    margin-top: 8px;
}
.lab-formula-line {
    font-size: 13.5px;
    color: #0F172A;
    font-weight: 600;
    line-height: 1.45;
}
.lab-formula-line strong {
    color: #E65100;
    font-weight: 700;
}
.lab-formula-sub {
    font-size: 12px;
    color: #475569;
    line-height: 1.5;
    margin-top: 2px;
    word-break: break-word;
}
.lab-formula-sub strong {
    color: #0F172A;
}

/* --- Responsive --- */
@media (max-width: 991px) {
    .lab-workspace {
        grid-template-columns: 1fr;
    }
    .lab-controls {
        max-height: none;
    }
}
@media (max-width: 768px) {
    .lab-tool-header {
        flex-direction: column;
        align-items: flex-start;
    }
    .lab-progress-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 480px) {
    .lab-workspace {
        padding: var(--lab-space-md);
        gap: var(--lab-space-md);
    }
}