/**
 * STEM Learning Hub - Engineering Page Styles
 * Interactive and engaging design for 8th graders
 */

/* =========================================
   Engineering Page Variables
   ========================================= */
:root {
    --engineering-color: #f59e0b;
    --engineering-light: rgba(245, 158, 11, 0.1);
    --engineering-dark: #d97706;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
}

/* =========================================
   Animations
   ========================================= */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes expandIn {
    from {
        opacity: 0;
        max-height: 0;
        padding: 0;
    }
    to {
        opacity: 1;
        max-height: 500px;
        padding: var(--spacing-md);
    }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

@keyframes compress {
    0%, 100% { transform: scaleX(1); }
    50% { transform: scaleX(0.7); }
}

@keyframes stretch {
    0%, 100% { transform: scaleX(1); }
    50% { transform: scaleX(1.3); }
}

@keyframes shear {
    0%, 100% { transform: skewX(0deg); }
    50% { transform: skewX(15deg); }
}

@keyframes twist {
    0%, 100% { transform: rotate(0deg); }
    25% { transform: rotate(10deg); }
    75% { transform: rotate(-10deg); }
}

@keyframes applyForce {
    0% { transform: scale(1); }
    50% { transform: scale(0.9) translateY(10px); }
    100% { transform: scale(1); }
}

@keyframes bridgeFall {
    to {
        transform: translateY(50px) rotate(30deg);
        opacity: 0;
    }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* =========================================
   Design Process Interactive Steps
   ========================================= */
.design-step {
    cursor: pointer;
    transition: all var(--transition-base);
}

.design-step:hover {
    transform: translateX(5px);
}

.design-step:focus {
    outline: 2px solid var(--engineering-color);
    outline-offset: 4px;
}

.design-step.expanded .step-circle {
    transform: scale(1.2);
    box-shadow: 0 0 0 4px var(--engineering-light);
}

.step-details {
    margin-top: var(--spacing-md);
    overflow: hidden;
}

.detail-content {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--engineering-color);
}

.detail-content h5 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-sm);
}

.detail-content ul {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.detail-content li {
    position: relative;
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
}

.detail-content li::before {
    content: '→';
    position: absolute;
    left: -1.5rem;
    color: var(--engineering-color);
}

.detail-activity {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    background: var(--bg-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-sm);
}

.activity-icon {
    font-size: 1.25rem;
}

.activity-text {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-style: italic;
}

/* Start Project Button */
.start-project-btn {
    margin-top: var(--spacing-lg);
    width: 100%;
}

/* =========================================
   Project Form Modal
   ========================================= */
.project-form-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    padding: var(--spacing-md);
}

.project-form-modal.active {
    opacity: 1;
    visibility: visible;
}

.project-form-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    transform: translateY(20px);
    transition: transform var(--transition-base);
}

.project-form-modal.active .project-form-content {
    transform: translateY(0);
}

.close-modal {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    font-size: 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.close-modal:hover {
    color: var(--text-primary);
}

.form-step {
    display: none;
}

.form-step.active {
    display: block;
    animation: slideIn 0.3s ease;
}

.form-step h4 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-md);
}

.form-step label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.form-step input,
.form-step textarea,
.form-step select {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
}

.form-step input:focus,
.form-step textarea:focus,
.form-step select:focus {
    outline: none;
    border-color: var(--engineering-color);
}

.form-step input.error,
.form-step textarea.error {
    border-color: var(--error-color);
    animation: shake 0.3s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.form-step textarea {
    min-height: 100px;
    resize: vertical;
}

.idea-input {
    margin-bottom: var(--spacing-sm);
}

.add-idea-btn {
    margin-top: var(--spacing-sm);
}

.form-progress {
    margin: var(--spacing-xl) 0 var(--spacing-md);
}

.progress-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--engineering-color), var(--engineering-dark));
    border-radius: var(--radius-full);
    transition: width var(--transition-base);
}

.progress-text {
    display: block;
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-top: var(--spacing-sm);
}

.form-navigation {
    display: flex;
    gap: var(--spacing-md);
    justify-content: space-between;
}

.form-navigation button {
    flex: 1;
}

/* Project Success */
.project-success {
    text-align: center;
    padding: var(--spacing-xl);
}

.success-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    animation: pulse 0.5s ease;
}

.project-success h3 {
    color: var(--success-color);
    margin-bottom: var(--spacing-md);
}

.project-summary {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: left;
    margin: var(--spacing-lg) 0;
}

.project-summary h4 {
    margin-bottom: var(--spacing-sm);
}

.next-step-prompt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

/* =========================================
   Engineer Cards Interactive
   ========================================= */
.engineer-card {
    cursor: pointer;
    position: relative;
}

.engineer-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.engineer-card.active {
    z-index: 10;
}

.engineer-expanded {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: 300px;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    margin-top: var(--spacing-sm);
}

.engineer-expanded.active {
    opacity: 1;
    visibility: visible;
}

.engineer-expanded::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 8px solid var(--bg-primary);
}

.engineer-detail-grid {
    display: grid;
    gap: var(--spacing-md);
}

.detail-section h5 {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.detail-section p {
    font-size: var(--font-size-sm);
    margin: 0;
}

.detail-section.full-width {
    grid-column: 1 / -1;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.skill-tag {
    background: var(--engineering-light);
    color: var(--engineering-dark);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
}

/* =========================================
   Lever Simulator
   ========================================= */
.lever-simulator {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px dashed var(--border-color);
}

.lever-simulator h5 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-lg);
}

.lever-container {
    background: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.lever-visual {
    position: relative;
    height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.lever-arm {
    width: 80%;
    height: 12px;
    background: linear-gradient(to right, #8b5cf6, var(--engineering-color));
    border-radius: var(--radius-full);
    position: relative;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform var(--transition-base);
    --fulcrum-position: 50%;
}

.lever-arm::before {
    content: '';
    position: absolute;
    left: var(--fulcrum-position);
    bottom: -20px;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 20px solid transparent;
    border-right: 20px solid transparent;
    border-bottom: 20px solid var(--text-primary);
}

.fulcrum-marker {
    position: absolute;
    left: var(--fulcrum-position);
    top: -25px;
    transform: translateX(-50%);
    font-size: 1.5rem;
    color: var(--text-primary);
}

.weight {
    position: absolute;
    background: var(--bg-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    text-align: center;
    font-size: var(--font-size-sm);
    top: -60px;
}

.effort-weight {
    left: 10%;
}

.load-weight {
    right: 10%;
}

.weight-value {
    display: block;
    font-weight: 700;
    color: var(--engineering-color);
}

.lever-controls {
    display: grid;
    gap: var(--spacing-lg);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.control-group label {
    font-weight: 500;
}

.control-group input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: var(--radius-full);
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--engineering-color);
    cursor: pointer;
    box-shadow: var(--shadow-md);
}

.position-labels {
    display: flex;
    justify-content: space-between;
    font-size: var(--font-size-sm);
    color: var(--text-light);
}

.lever-results {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.result-box {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
}

.result-box .result-label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.result-box .result-value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--engineering-color);
}

.result-box.status .result-value {
    font-size: var(--font-size-base);
}

/* =========================================
   Pulley Simulator
   ========================================= */
.pulley-simulator {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px dashed var(--border-color);
}

.pulley-simulator h5 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-lg);
}

.pulley-container {
    background: var(--bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.pulley-visual {
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.pulley-system {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.pulley {
    position: relative;
}

.pulley-wheel {
    width: 60px;
    height: 60px;
    border: 4px solid var(--text-primary);
    border-radius: 50%;
    background: var(--bg-primary);
    position: relative;
}

.pulley-wheel::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    background: var(--text-primary);
    border-radius: 50%;
}

.pulley.pulleys-2 .pulley-wheel,
.pulley.pulleys-4 .pulley-wheel {
    box-shadow: 30px 0 0 -4px var(--text-primary), 30px 0 0 0 var(--bg-primary);
}

.pulley.pulleys-4 .pulley-wheel {
    box-shadow: 30px 0 0 -4px var(--text-primary), 30px 0 0 0 var(--bg-primary),
                60px 0 0 -4px var(--text-primary), 60px 0 0 0 var(--bg-primary),
                90px 0 0 -4px var(--text-primary), 90px 0 0 0 var(--bg-primary);
}

.pulley-load {
    margin-top: var(--spacing-lg);
}

.load-box {
    background: var(--engineering-color);
    color: white;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-weight: 700;
}

.pulley-effort {
    position: absolute;
    left: -80px;
    top: 50%;
    transform: translateY(-50%);
    text-align: center;
}

.person-icon {
    font-size: 2rem;
}

.effort-arrow {
    font-size: var(--font-size-sm);
    color: var(--success-color);
    font-weight: 600;
}

.pulley-controls {
    margin-top: var(--spacing-lg);
}

.pulley-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
}

.pulley-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pulley-btn:hover {
    background: var(--border-color);
}

.pulley-btn.active {
    background: var(--engineering-color);
    border-color: var(--engineering-color);
    color: white;
}

.pulley-info {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.pulley-info p {
    margin: 0;
    font-size: var(--font-size-sm);
}

.pulley-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.pulley-stats .stat {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
}

.pulley-stats .stat-label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.pulley-stats .stat-value {
    display: block;
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--engineering-color);
}

/* =========================================
   MA Calculator
   ========================================= */
.ma-calculator {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
}

.ma-calculator h4 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-lg);
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.calc-input-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.input-with-unit {
    display: flex;
    align-items: center;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.input-with-unit input {
    flex: 1;
    padding: var(--spacing-md);
    border: none;
    font-size: var(--font-size-lg);
    outline: none;
}

.input-with-unit .unit {
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    font-weight: 600;
    color: var(--text-secondary);
}

.calculate-ma-btn {
    width: 100%;
    margin-bottom: var(--spacing-lg);
}

.ma-result {
    text-align: center;
}

.ma-value {
    margin-bottom: var(--spacing-md);
}

.big-number {
    display: block;
    font-size: 4rem;
    font-weight: 700;
    color: var(--engineering-color);
    line-height: 1;
    transition: transform var(--transition-fast);
}

.big-number.pulse {
    animation: pulse 0.5s ease;
}

.ma-label {
    display: block;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.ma-interpretation {
    padding: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    transition: color var(--transition-fast);
}

/* =========================================
   Machine Matching Game
   ========================================= */
.machine-game {
    margin-top: var(--spacing-xl);
}

.matching-game {
    display: grid;
    gap: var(--spacing-xl);
    margin: var(--spacing-lg) 0;
}

.examples-container {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    min-height: 60px;
}

.draggable-example {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-primary);
    border: 2px solid var(--engineering-color);
    border-radius: var(--radius-md);
    cursor: grab;
    font-weight: 500;
    transition: all var(--transition-fast);
    user-select: none;
}

.draggable-example:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.draggable-example.dragging {
    opacity: 0.5;
    cursor: grabbing;
}

.touch-clone {
    position: fixed;
    z-index: 1000;
    pointer-events: none;
    transform: translate(-50%, -50%);
}

.drop-zones {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.drop-zone {
    background: var(--bg-secondary);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    text-align: center;
    min-height: 120px;
    transition: all var(--transition-fast);
}

.drop-zone.drag-over {
    border-color: var(--engineering-color);
    background: var(--engineering-light);
}

.drop-zone.wrong {
    border-color: var(--error-color);
    animation: shake 0.3s ease;
}

.zone-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: var(--spacing-xs);
}

.zone-label {
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.dropped-items {
    margin-top: var(--spacing-sm);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.dropped-item {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--success-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    animation: slideIn 0.3s ease;
}

.game-status {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.score {
    font-weight: 600;
    font-size: var(--font-size-lg);
}

#match-score {
    color: var(--engineering-color);
    font-size: var(--font-size-xl);
}

/* =========================================
   Force Cards Interactive
   ========================================= */
.force-card {
    cursor: pointer;
    transition: all var(--transition-base);
}

.force-card:hover {
    transform: scale(1.05);
}

.force-card.preview .force-visual {
    color: var(--engineering-color);
}

.force-card.animating {
    box-shadow: 0 0 0 3px var(--engineering-color);
}

/* =========================================
   Shape Strength Test
   ========================================= */
.shape-strength-test {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
}

.shape-strength-test h4 {
    margin-bottom: var(--spacing-sm);
}

.shape-strength-test > p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.shape-test-area {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.test-shape {
    text-align: center;
    cursor: pointer;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.test-shape:hover {
    background: var(--bg-secondary);
}

.test-shape.testing .shape-svg {
    animation: applyForce 1s ease-in-out forwards;
}

.test-shape.passed {
    background: rgba(16, 185, 129, 0.1);
}

.test-shape.passed .shape-svg {
    color: var(--success-color);
}

.test-shape.failed {
    background: rgba(239, 68, 68, 0.1);
}

.test-shape.failed .shape-svg {
    color: var(--error-color);
    transform: skewX(15deg);
}

.shape-svg {
    width: 80px;
    height: 80px;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.test-shape span {
    font-weight: 600;
}

.strength-result {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    text-align: center;
}

.strength-result .success {
    color: var(--success-color);
}

.strength-result .warning {
    color: var(--error-color);
}

.strength-result .tip {
    margin-top: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

/* =========================================
   Bridge Builder Game
   ========================================= */
.bridge-builder {
    background: linear-gradient(135deg, var(--engineering-light) 0%, var(--bg-primary) 100%);
    border: 2px solid var(--engineering-color);
}

.bridge-game {
    margin: var(--spacing-lg) 0;
}

.bridge-canvas {
    position: relative;
    height: 250px;
    background: linear-gradient(to bottom, #87CEEB 0%, #87CEEB 60%, #228B22 60%, #228B22 100%);
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: crosshair;
}

.bridge-start,
.bridge-end {
    position: absolute;
    bottom: 40%;
    font-size: 3rem;
    z-index: 10;
}

.bridge-start {
    left: 10px;
}

.bridge-end {
    right: 10px;
}

.bridge-gap {
    position: absolute;
    left: 60px;
    right: 60px;
    bottom: 0;
    height: 40%;
    background: #4169E1;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.water {
    text-align: center;
    padding-top: var(--spacing-md);
    letter-spacing: 10px;
    animation: float 2s ease-in-out infinite;
}

.bridge-deck {
    position: absolute;
    left: 60px;
    right: 60px;
    bottom: 40%;
    height: 10px;
    background: #8B4513;
    border-radius: var(--radius-sm);
}

.beams-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
}

.bridge-beam {
    position: absolute;
    background: #654321;
    pointer-events: auto;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.bridge-beam:hover {
    background: var(--error-color);
}

.beam-horizontal {
    width: 60px;
    height: 6px;
}

.beam-diagonal-left {
    width: 60px;
    height: 6px;
    transform: rotate(45deg);
}

.beam-diagonal-right {
    width: 60px;
    height: 6px;
    transform: rotate(-45deg);
}

.beam-vertical {
    width: 6px;
    height: 50px;
}

.test-truck {
    position: absolute;
    left: 0;
    bottom: calc(40% + 10px);
    font-size: 2rem;
    z-index: 20;
    transition: left 3s linear;
}

.bridge-controls {
    margin-top: var(--spacing-lg);
}

.beam-selector {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.beam-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: monospace;
    transition: all var(--transition-fast);
}

.beam-btn:hover {
    background: var(--border-color);
}

.beam-btn.active {
    background: var(--engineering-color);
    border-color: var(--engineering-color);
    color: white;
}

.bridge-stats {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
}

.bridge-stats .stat {
    background: var(--bg-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
}

.bridge-stats .stat-label {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.bridge-stats .stat-value {
    font-weight: 700;
    color: var(--engineering-color);
}

.bridge-stats .stat-max {
    color: var(--text-light);
}

.bridge-actions {
    display: flex;
    gap: var(--spacing-md);
}

.bridge-tips {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.bridge-tips h4 {
    margin-bottom: var(--spacing-sm);
}

.bridge-tips ul {
    margin-left: var(--spacing-lg);
}

.bridge-tips li {
    position: relative;
    padding: var(--spacing-xs) 0;
    color: var(--text-secondary);
}

.bridge-tips li::before {
    content: '→';
    position: absolute;
    left: -1.5rem;
    color: var(--engineering-color);
}

/* =========================================
   Challenge Tracker
   ========================================= */
.challenge-tracker {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px solid var(--engineering-color);
}

.challenge-tracker h4 {
    color: var(--engineering-color);
    margin-bottom: var(--spacing-lg);
}

.tracker-form {
    display: grid;
    gap: var(--spacing-md);
}

.tracker-form .input-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.tracker-form label {
    font-weight: 500;
}

.tracker-form input,
.tracker-form textarea {
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
}

.tracker-form input:focus,
.tracker-form textarea:focus {
    outline: none;
    border-color: var(--engineering-color);
}

.tracker-form textarea {
    min-height: 80px;
    resize: vertical;
}

.save-attempt-btn {
    margin-top: var(--spacing-sm);
}

.attempts-list {
    margin-top: var(--spacing-xl);
}

.attempts-list h5 {
    margin-bottom: var(--spacing-md);
}

.no-attempts {
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
    padding: var(--spacing-lg);
}

.best-attempt {
    background: linear-gradient(135deg, var(--engineering-color) 0%, var(--engineering-dark) 100%);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.best-label {
    font-weight: 600;
}

.best-value {
    font-size: var(--font-size-lg);
    font-weight: 700;
}

.attempts-scroll {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.attempt-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.attempt-item.best {
    background: var(--engineering-light);
}

.attempt-rank {
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: 50%;
    font-weight: 700;
}

.attempt-item.best .attempt-rank {
    background: var(--engineering-color);
    color: white;
}

.attempt-stats {
    flex: 1;
    font-weight: 500;
}

.attempt-date {
    font-size: var(--font-size-sm);
    color: var(--text-light);
}

/* =========================================
   Achievements Bar
   ========================================= */
.achievements-bar {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.achievements-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: linear-gradient(135deg, #ffd700 0%, #ffb700 100%);
    border-radius: var(--radius-full);
    font-weight: 600;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.achievements-toggle:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.achievement-count {
    background: white;
    color: #b8860b;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: var(--font-size-sm);
}

.achievements-panel {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-sm);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-base);
    z-index: 100;
}

.achievements-panel.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.achievements-panel h4 {
    margin-bottom: var(--spacing-lg);
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.achievement {
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-fast);
}

.achievement.earned {
    background: linear-gradient(135deg, #ffd700 0%, #ffb700 100%);
    color: #7b5800;
}

.achievement.locked {
    background: var(--bg-secondary);
    color: var(--text-light);
}

.achievement-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: var(--spacing-xs);
}

.achievement-name {
    display: block;
    font-weight: 600;
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-xs);
}

.achievement-desc {
    display: block;
    font-size: 0.75rem;
}

.earned-date {
    display: block;
    font-size: 0.7rem;
    margin-top: var(--spacing-xs);
    opacity: 0.8;
}

/* Achievement Notification */
.achievement-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 3000;
    opacity: 0;
    transform: translateX(100%);
    transition: all var(--transition-base);
}

.achievement-notification.show {
    opacity: 1;
    transform: translateX(0);
}

.achievement-popup {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: linear-gradient(135deg, #ffd700 0%, #ffb700 100%);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.achievement-trophy {
    font-size: 2rem;
    animation: pulse 1s ease infinite;
}

.achievement-text {
    display: flex;
    flex-direction: column;
}

.achievement-label {
    font-size: var(--font-size-sm);
    color: #7b5800;
}

.achievement-title {
    font-weight: 700;
    color: #4a3500;
}

/* =========================================
   Quiz Styles
   ========================================= */
.quiz-card {
    margin-top: var(--spacing-xl);
}

.quiz-container {
    margin-top: var(--spacing-lg);
}

.quiz-question {
    animation: slideIn 0.3s ease;
}

.question-number {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: var(--spacing-sm);
}

.question-text {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
}

.quiz-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-bottom: var(--spacing-sm);
}

.quiz-option:hover {
    background: rgba(255, 255, 255, 0.2);
}

.quiz-option input {
    width: 20px;
    height: 20px;
}

.quiz-option.correct {
    background: var(--success-color) !important;
}

.quiz-option.incorrect {
    background: var(--error-color) !important;
}

.check-answer {
    margin-top: var(--spacing-md);
}

.quiz-feedback {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
}

.quiz-feedback p.correct {
    color: #4ade80;
}

.quiz-feedback p.incorrect {
    color: #fca5a5;
}

.explanation {
    font-size: var(--font-size-sm);
    opacity: 0.9;
    margin-top: var(--spacing-sm);
}

.next-question {
    margin-top: var(--spacing-md);
}

.quiz-complete {
    color: #4ade80;
    font-weight: 700;
    font-size: var(--font-size-lg);
}

/* =========================================
   Notifications
   ========================================= */
.notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-weight: 500;
    z-index: 2000;
    opacity: 0;
    transform: translateY(20px);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-lg);
}

.notification.show {
    opacity: 1;
    transform: translateY(0);
}

.notification-success {
    background: var(--success-color);
    color: white;
}

.notification-error {
    background: var(--error-color);
    color: white;
}

.notification-warning {
    background: var(--warning-color);
    color: white;
}

.notification-info {
    background: var(--primary-color);
    color: white;
}

/* =========================================
   Responsive Adjustments
   ========================================= */
@media (max-width: 768px) {
    .engineer-expanded {
        position: fixed;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        width: 90%;
        max-width: 350px;
    }

    .lever-results {
        grid-template-columns: 1fr;
    }

    .pulley-stats {
        grid-template-columns: 1fr;
    }

    .drop-zones {
        grid-template-columns: repeat(2, 1fr);
    }

    .beam-selector {
        flex-direction: column;
    }

    .beam-btn {
        width: 100%;
    }

    .bridge-stats {
        flex-direction: column;
    }

    .achievements-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .shape-test-area {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .project-form-content {
        padding: var(--spacing-md);
    }

    .form-navigation {
        flex-direction: column;
    }

    .drop-zones {
        grid-template-columns: 1fr;
    }

    .achievements-panel {
        padding: var(--spacing-md);
    }
}

/* =========================================
   Print Styles
   ========================================= */
@media print {
    .achievements-bar,
    .lever-simulator,
    .pulley-simulator,
    .ma-calculator,
    .machine-game,
    .shape-strength-test,
    .bridge-builder,
    .challenge-tracker,
    .quiz-card,
    .start-project-btn,
    .notification,
    .achievement-notification {
        display: none !important;
    }
}