/**
 * Experiment 2: Friction Force Measurement
 * Styles specific to this experiment
 * v2.0 - Dark theme matching spring experiment
 */

/* ==================== CSS VARIABLES (matching spring) ==================== */
:root {
    --primary-color: #00A86B;
    --secondary-color: #0066CC;
    --accent-color: #FFD700;
    --bg-primary: #0a0e27;
    --bg-secondary: #1a1f3a;
    --bg-tertiary: #252b4a;
    --text-primary: #FFFFFF;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --border-color: rgba(255, 255, 255, 0.15);
    --glass-bg: rgba(26, 31, 58, 0.9);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

/* ==================== BODY & CONTAINER ==================== */
body {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 50%, #0d1233 100%);
    color: var(--text-primary);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
}

.experiment-container {
    max-width: 1800px;
    margin: 0 auto;
    padding: 1rem 2rem;
}

/* ==================== CANVAS CONTAINER ==================== */
.canvas-container {
    position: relative;
    width: 100%;
    height: 600px;
    background: linear-gradient(135deg, #1a1f3a 0%, #0a0e27 100%);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5), inset 0 0 60px rgba(0, 102, 204, 0.1);
    border: 1px solid var(--glass-border);
}

.canvas-container canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

#canvas-background { z-index: 1; }
#canvas-equipment { z-index: 2; }
#canvas-dynamic { z-index: 3; }
#canvas-particles { z-index: 4; pointer-events: none; }
#canvas-ui { z-index: 5; }

#drag-drop-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 100;
    pointer-events: none;
    background: transparent;
}

/* Стиль canvas-container при перетаскивании */
.canvas-container.drag-over {
    box-shadow: 0 0 30px rgba(0, 168, 107, 0.6), inset 0 0 60px rgba(0, 168, 107, 0.2) !important;
    border: 3px dashed #00A86B !important;
}

.canvas-container.drag-over {
    box-shadow: 0 0 30px rgba(0, 168, 107, 0.5), inset 0 0 60px rgba(0, 168, 107, 0.2);
    border-color: var(--primary-color);
}

/* ==================== HEADER ==================== */
.experiment-header {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.experiment-header h1 {
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==================== SURFACE SELECTOR ==================== */
.surface-selector {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--glass-bg);
    padding: 8px 16px;
    border-radius: 10px;
    border: 1px solid var(--glass-border);
}

.surface-selector label {
    font-weight: 600;
    color: var(--text-secondary);
}

.surface-selector select {
    padding: 8px 14px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}

.surface-selector select:hover {
    border-color: var(--secondary-color);
}

.surface-selector select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 168, 107, 0.3);
}

/* ==================== EXPERIMENT INSTRUCTIONS ==================== */
.experiment-instructions {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 16px;
    margin-top: 16px;
    border-left: 4px solid var(--primary-color);
    border: 1px solid var(--glass-border);
}

.experiment-instructions h3 {
    margin: 0 0 12px 0;
    color: var(--primary-color);
    font-size: 16px;
}

.experiment-instructions ol {
    margin: 0;
    padding-left: 24px;
    color: var(--text-secondary);
}

.experiment-instructions li {
    margin-bottom: 6px;
    line-height: 1.5;
}

.experiment-instructions li::marker {
    color: var(--primary-color);
    font-weight: bold;
}

/* ==================== EQUIPMENT GRID (matching spring experiment) ==================== */
.equipment-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.6rem;
    max-height: 220px;
    overflow-y: auto;
    padding: 0.4rem;
}

.equipment-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
    padding: 0.75rem 0.5rem;
    background: var(--bg-tertiary);
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    cursor: grab;
    transition: all 0.2s ease;
    user-select: none;
    min-height: 95px;
    box-sizing: border-box;
    touch-action: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}

.equipment-item:not(.used):hover {
    transform: translateY(-3px) scale(1.02);
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(0, 168, 107, 0.3);
}

.equipment-item:active {
    cursor: grabbing;
    transform: scale(1.05);
}

.equipment-item.dragging {
    opacity: 0.9;
    transform: scale(1.05);
    z-index: 1000;
    box-shadow: 0 8px 24px rgba(0, 168, 107, 0.5);
    border-color: var(--primary-color);
    /* 🚀 GPU-ускорение */
    will-change: transform;
    backface-visibility: hidden;
}

.equipment-item--installed {
    border-style: solid;
    border-color: var(--primary-color);
    box-shadow: 0 10px 24px rgba(0, 168, 107, 0.3);
}

.equipment-figure {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.06);
    padding: 0.25rem;
}

.equipment-preview {
    max-width: 80px;
    max-height: 70px;
    pointer-events: none;
}

.equipment-icon {
    font-size: 2rem;
    line-height: 1;
}

.equipment-title,
.equipment-name {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    line-height: 1.2;
}

.equipment-mass {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
}

/* ==================== WEIGHTS CONTAINER (matching spring experiment) ==================== */
.weights-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.6rem;
    max-height: 280px;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 0.4rem;
    touch-action: pan-y;
    -webkit-overflow-scrolling: touch;
    scroll-behavior: smooth;
    padding-right: 8px;
}

.weight-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
    padding: 0.75rem 0.5rem;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: grab;
    transition: all 0.2s ease;
    user-select: none;
    min-height: 95px;
    box-sizing: border-box;
    touch-action: none;
    -webkit-user-select: none;
    -webkit-touch-callout: none;
}

.weight-item:not(.used):not([data-status="pending"]):hover {
    transform: translateY(-3px) scale(1.02);
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(0, 168, 107, 0.3);
}

.weight-item:active {
    cursor: grabbing;
    transform: scale(1.05);
}

.weight-item.dragging {
    opacity: 0.9;
    transform: scale(1.05);
    z-index: 1000;
    box-shadow: 0 8px 24px rgba(0, 168, 107, 0.5);
    border-color: var(--primary-color);
    /* 🚀 GPU-ускорение вместо тяжёлой анимации */
    will-change: transform;
    backface-visibility: hidden;
}

.weight-figure {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    aspect-ratio: 1 / 1;
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.06);
    padding: 0.25rem;
}

.weight-figure img,
.weight-figure canvas {
    max-width: 55px;
    max-height: 55px;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.35));
    pointer-events: none;
}

.weight-icon-img {
    max-width: 60px;
    max-height: 60px;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.35));
    pointer-events: none;
}

.weight-preview {
    border-radius: 6px;
}

.weight-placeholder {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--text-secondary);
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.05);
}

.weight-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    line-height: 1.2;
}

.weight-status {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* ==================== MEASUREMENT WINDOW ==================== */
.measurement-window {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
    color: var(--text-primary);
}

.formula-display {
    text-align: center;
    font-size: 22px;
    font-family: 'Cambria Math', 'Times New Roman', serif;
    color: var(--accent-color);
    padding: 14px;
    background: rgba(0, 102, 204, 0.2);
    border-radius: 10px;
    margin-bottom: 16px;
    border: 1px solid rgba(0, 102, 204, 0.3);
}

.current-values {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.value-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    border: 1px solid var(--glass-border);
}

.value-row.highlight {
    background: rgba(229, 62, 62, 0.15);
    border: 1px solid rgba(229, 62, 62, 0.5);
}

.value-row .label {
    color: var(--text-secondary);
    font-size: 14px;
}

.value-row .value {
    color: var(--primary-color);
    font-size: 18px;
    font-weight: bold;
    font-family: 'JetBrains Mono', 'Courier New', monospace;
}

.value-row.highlight .value {
    color: #fc8181;
}

/* ==================== DATA TABLE ==================== */
.data-table-container {
    max-height: 200px;
    overflow-y: auto;
    border-radius: 10px;
    border: 1px solid var(--glass-border);
    background: rgba(0, 0, 0, 0.2);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}

.data-table thead {
    background: rgba(0, 102, 204, 0.3);
    color: var(--accent-color);
    position: sticky;
    top: 0;
}

.data-table th,
.data-table td {
    padding: 10px 12px;
    text-align: center;
    border-bottom: 1px solid var(--glass-border);
}

.data-table th {
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.3px;
}

.data-table td {
    color: var(--text-primary);
    font-family: 'JetBrains Mono', 'Courier New', monospace;
}

.data-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.05);
}

.data-table tbody tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.02);
}

.table-actions {
    display: flex;
    gap: 10px;
    margin-top: 14px;
}

/* ==================== RESULTS WINDOW ==================== */
.results-window {
    background: linear-gradient(135deg, rgba(0, 168, 107, 0.15) 0%, rgba(0, 102, 204, 0.15) 100%);
    border: 2px solid var(--primary-color);
    border-radius: 16px;
    padding: 20px;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 14px;
}

.result-row .label {
    color: var(--text-secondary);
    font-weight: 600;
}

.result-row .value {
    font-size: 28px;
    font-weight: bold;
    color: var(--primary-color);
    font-family: 'JetBrains Mono', 'Courier New', monospace;
}

/* ==================== CHART CONTAINER ==================== */
.chart-container {
    height: 200px;
    background: var(--glass-bg);
    border-radius: 12px;
    padding: 14px;
    border: 1px solid var(--glass-border);
}

/* ==================== BUTTONS ==================== */
.btn-primary {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color) 0%, #00896B 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(0, 168, 107, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 168, 107, 0.5);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    flex: 1;
    padding: 12px;
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 2px solid var(--glass-border);
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-secondary:hover {
    background: rgba(0, 102, 204, 0.2);
    border-color: var(--secondary-color);
}

/* Icon buttons (header) */
.btn-icon {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    width: 42px;
    height: 42px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    background: rgba(0, 102, 204, 0.3);
    transform: scale(1.1);
}

.btn-icon.active {
    background: rgba(0, 168, 107, 0.3);
    border-color: var(--primary-color);
}

/* ==================== HELP MODAL ==================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 14, 39, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--bg-secondary);
    border: 2px solid var(--glass-border);
    border-radius: 20px;
    padding: 28px;
    max-width: 650px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
}

.modal-close {
    position: absolute;
    top: 18px;
    right: 18px;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all 0.2s;
}

.modal-close:hover {
    color: #e53e3e;
    transform: scale(1.2);
}

.help-content h3 {
    color: var(--primary-color);
    margin-top: 22px;
    margin-bottom: 12px;
}

.help-content p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.help-content ul {
    color: var(--text-secondary);
    padding-left: 22px;
}

.formula-box {
    background: rgba(0, 102, 204, 0.15);
    border: 2px solid rgba(0, 102, 204, 0.3);
    border-radius: 12px;
    padding: 18px;
    text-align: center;
    font-size: 22px;
    font-family: 'Cambria Math', serif;
    color: var(--accent-color);
    margin: 14px 0;
}

.help-table {
    width: 100%;
    border-collapse: collapse;
    margin: 14px 0;
}

.help-table td {
    padding: 10px 14px;
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
}

.help-table tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.03);
}

/* ==================== STATUS MESSAGES ==================== */
.status-success {
    color: var(--primary-color) !important;
}

.status-warning {
    color: #ed8936 !important;
}

.status-error {
    color: #e53e3e !important;
}

.status-info {
    color: var(--secondary-color) !important;
}

.experiment-status {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ==================== LOADING OVERLAY ==================== */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 14, 39, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--glass-border);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-overlay p {
    color: var(--text-secondary);
    margin-top: 16px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ==================== DRAG DROP OVERLAY ==================== */
/* NOTE: Defined earlier with pointer-events: none, only activate on drag */
#drag-drop-overlay.drag-over {
    background: rgba(0, 168, 107, 0.1);
    border: 3px dashed #00A86B;
    box-shadow: inset 0 0 30px rgba(0, 168, 107, 0.3);
}
    background: rgba(0, 168, 107, 0.1);
    border: 3px dashed var(--primary-color);
    pointer-events: auto;
}

/* ==================== CONTROL PANEL ==================== */
.control-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
    margin-top: 1rem;
}

.control-panel h3 {
    color: var(--text-primary);
    margin-bottom: 14px;
    font-size: 1.1rem;
}

/* ==================== SECTIONS ==================== */
.panel-section {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
}

.panel-section h4 {
    color: var(--primary-color);
    margin-bottom: 14px;
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 768px) {
    .weights-container,
    .equipment-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .table-actions {
        flex-direction: column;
    }
    
    .formula-display {
        font-size: 18px;
    }
    
    .canvas-container {
        height: 450px;
    }
}

/* ==================== SCROLLBAR ==================== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: rgba(0, 102, 204, 0.5);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 102, 204, 0.7);
}

/* ==================== ACTION BUTTONS (matching spring experiment) ==================== */
.weight-action,
.equipment-action {
    display: block;
    width: 100%;
    margin-top: 0.5rem;
    padding: 0.6rem 0.75rem;
    background: linear-gradient(135deg, #0066CC, #0088FF);
    color: #FFFFFF;
    border: none;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 36px;
    text-align: center;
    box-shadow: 0 3px 8px rgba(0, 102, 204, 0.4);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.weight-action:hover,
.equipment-action:hover {
    background: linear-gradient(135deg, #0088FF, #00AAFF);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 102, 204, 0.6);
}

.weight-status,
.equipment-status {
    font-size: 0.75rem;
    color: var(--primary-color);
    margin-top: 0.25rem;
    font-weight: 500;
}

.weight-hint,
.equipment-hint {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
    opacity: 0.8;
    padding: 0.3rem 0.4rem;
    border-radius: 6px;
    background: rgba(0, 168, 107, 0.15);
    text-align: center;
}

.weight-item.used,
.equipment-item.used {
    opacity: 0.45;
    cursor: not-allowed;
    filter: grayscale(0.3);
}

/* При наведении на used элемент с кнопкой "Вернуть" */
.weight-item.used:hover,
.equipment-item.used:hover {
    opacity: 0.7;
    cursor: pointer;
}

/* ==================== MEASUREMENT INPUT STYLES (matching spring) ==================== */
.variable-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    padding: 12px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 10px;
    margin-bottom: 10px;
    transition: all 0.3s ease;
}

.variable-row:hover {
    background: rgba(255, 255, 255, 0.06);
}

.var-label {
    font-size: 1.2rem;
    font-weight: 700;
    color: #4A9EFF;
    font-family: 'Courier New', monospace;
    min-width: 40px;
}

.var-input-group {
    display: flex;
    flex: 1;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

.var-manual-input {
    flex: 1;
    min-width: 120px;
    padding: 10px 12px;
    font-size: 1rem;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.3);
    color: #fff;
    outline: none;
    transition: all 0.3s ease;
}

.var-manual-input:focus {
    border-color: #4A9EFF;
    box-shadow: 0 0 12px rgba(74, 158, 255, 0.3);
}

.var-manual-input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

.btn-record-var {
    padding: 10px 14px;
    font-size: 0.9rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    background: linear-gradient(135deg, #4A9EFF, #357ABD);
    color: white;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-record-var:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 158, 255, 0.4);
}

.btn-record-var:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.var-current-value {
    font-size: 1.1rem;
    font-weight: 700;
    color: #FFD700;
    font-family: 'Courier New', monospace;
    min-width: 50px;
}

/* Recorded Values */
.recorded-values {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin: 12px 0;
    padding: 12px;
    background: rgba(74, 255, 158, 0.08);
    border-radius: 10px;
    border: 1px solid rgba(74, 255, 158, 0.2);
}

.recorded-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.recorded-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

.recorded-value {
    font-size: 1.15rem;
    font-weight: 700;
    color: #4AFF9E;
    font-family: 'Courier New', monospace;
}

.recorded-unit {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
}

/* Action Buttons */
.action-buttons-group {
    display: flex;
    gap: 10px;
    margin: 16px 0;
}

.btn-reset-measurement {
    padding: 12px 16px;
    font-size: 0.95rem;
    font-weight: 600;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    cursor: pointer;
    background: transparent;
    color: white;
    transition: all 0.3s ease;
}

.btn-reset-measurement:hover {
    background: rgba(255, 59, 48, 0.2);
    border-color: #FF3B30;
    color: #FF3B30;
}

.btn-calculate-stiffness {
    flex: 1;
    padding: 12px 20px;
    font-size: 1.1rem;
    font-weight: 700;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    background: linear-gradient(135deg, #4AFF9E, #35BD7A);
    color: #0a3d2a;
    transition: all 0.3s ease;
}

.btn-calculate-stiffness:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 255, 158, 0.5);
}

.btn-calculate-stiffness:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
}

/* Calculation Result */
.calculation-result {
    background: linear-gradient(135deg, rgba(74, 255, 158, 0.12), rgba(53, 189, 122, 0.12));
    border: 2px solid #4AFF9E;
    border-radius: 12px;
    padding: 20px;
    animation: resultAppear 0.5s ease-out;
}

@keyframes resultAppear {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-formula {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 8px;
    font-family: 'Courier New', monospace;
}

.result-calculation {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 12px;
    font-family: 'Courier New', monospace;
}

.result-final {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.5rem;
}

.result-label {
    font-weight: 600;
    color: rgba(255, 255, 255, 0.8);
}

.result-value {
    font-weight: 700;
    color: #4AFF9E;
    font-family: 'Courier New', monospace;
}

.result-unit {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.6);
}

/* Success Button */
.btn-success {
    width: 100%;
    padding: 14px;
    font-size: 1.1rem;
    font-weight: 700;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    background: linear-gradient(135deg, var(--primary-color), #00cc7a);
    color: white;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 168, 107, 0.5);
}

.btn-success:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.btn-success .icon {
    font-size: 1.2rem;
}

/* ==================== WEIGHING ZONE ==================== */
.weighing-section {
    background: linear-gradient(135deg, rgba(0, 102, 204, 0.15), rgba(0, 168, 107, 0.1));
    border: 1px solid rgba(0, 168, 107, 0.3);
}

.weighing-zone {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.weighing-dynamometer-select {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
}

.weighing-dynamometer-select label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.weighing-dynamometer-select select {
    flex: 1;
    padding: 6px 10px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 0.9rem;
}

.weighing-canvas-wrapper {
    position: relative;
    width: 200px;
    height: 280px;
    background: linear-gradient(135deg, #1a1f3a 0%, #0a0e27 100%);
    border-radius: 12px;
    border: 2px dashed rgba(255, 255, 255, 0.2);
    overflow: hidden;
    transition: all 0.3s ease;
}

.weighing-canvas-wrapper.drag-over {
    border-color: var(--primary-color);
    box-shadow: 0 0 20px rgba(0, 168, 107, 0.4);
}

.weighing-canvas-wrapper.has-item {
    border-style: solid;
    border-color: var(--primary-color);
}

#canvas-weighing {
    width: 100%;
    height: 100%;
}

.weighing-drop-hint {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.85rem;
    pointer-events: none;
    transition: opacity 0.3s;
}

.weighing-canvas-wrapper.has-item .weighing-drop-hint {
    opacity: 0;
}

.weighing-result {
    display: flex;
    align-items: baseline;
    gap: 4px;
    padding: 8px 16px;
    background: rgba(0, 168, 107, 0.2);
    border-radius: 8px;
    border: 1px solid rgba(0, 168, 107, 0.4);
}

.weighing-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: #4AFF9E;
    font-family: 'Courier New', monospace;
}

.weighing-unit {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.7);
}

.weighing-actions {
    display: flex;
    gap: 8px;
    width: 100%;
}

.btn-weighing-record,
.btn-weighing-clear {
    flex: 1;
    padding: 8px 12px;
    border-radius: 8px;
    border: none;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-weighing-record {
    background: linear-gradient(135deg, var(--primary-color), #00cc7a);
    color: white;
}

.btn-weighing-record:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 168, 107, 0.4);
}

.btn-weighing-clear {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.btn-weighing-clear:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.15);
}

.btn-weighing-record:disabled,
.btn-weighing-clear:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.weighing-quick-actions {
    width: 100%;
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px dashed rgba(255, 255, 255, 0.15);
}

.btn-weigh-block {
    width: 100%;
    padding: 10px 12px;
    border-radius: 8px;
    border: 1px dashed rgba(0, 168, 107, 0.5);
    background: rgba(0, 168, 107, 0.1);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.btn-weigh-block:hover {
    background: rgba(0, 168, 107, 0.2);
    border-color: var(--primary-color);
}