/* DataRetablo - Modern Styling */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #475569;
    --accent-color: #f59e0b;
    --bg-light: #f8fafc;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --success-color: #10b981;
}

body {
    background-color: var(--bg-light);
    color: var(--text-dark);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    min-height: 100vh;
}

.navbar-brand {
    font-weight: 700;
    letter-spacing: -0.5px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.step-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: box-shadow 0.2s ease;
}

.step-card:hover {
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.08);
}

.step-header {
    background: #f1f5f9;
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.step-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--primary-color);
    color: white;
    font-weight: 700;
    font-size: 0.85rem;
    border-radius: 50%;
    margin-right: 0.5rem;
}

.step-title {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
}

.drop-zone {
    border: 2px dashed #cbd5e1;
    border-radius: 10px;
    padding: 2.5rem 1.5rem;
    text-align: center;
    background: #f8fafc;
    cursor: pointer;
    transition: all 0.2s ease;
}

.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.drop-zone i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.preview-canvas-container {
    background: #1e293b;
    border-radius: 10px;
    padding: 1rem;
    position: relative;
    overflow: auto;
    max-height: 600px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#previewCanvas {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    background: #fff;
    max-width: 100%;
    height: auto;
    cursor: crosshair;
}

.student-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.student-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.student-thumb {
    width: 48px;
    height: 58px;
    object-fit: cover;
    border-radius: 4px;
    border: 1px solid #e2e8f0;
}

.student-input {
    font-size: 0.85rem;
    font-weight: 600;
}

.students-container {
    max-height: 420px;
    overflow-y: auto;
    padding-right: 0.5rem;
}

.form-label-sm {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.25rem;
}

.unit-addon {
    font-size: 0.75rem;
    font-weight: 600;
    background: #e2e8f0;
    color: #475569;
}

.legend-box {
    display: inline-block;
    width: 14px;
    height: 14px;
    border-radius: 3px;
    vertical-align: middle;
    margin-right: 5px;
}

.legend-big {
    background: rgba(37, 99, 235, 0.6);
    border: 1px solid #1d4ed8;
}

.legend-thumb {
    background: rgba(16, 185, 129, 0.6);
    border: 1px solid #059669;
}

.canvas-coord-badge {
    position: absolute;
    bottom: 12px;
    left: 12px;
    background: rgba(15, 23, 42, 0.85);
    color: #fff;
    padding: 4px 10px;
    border-radius: 6px;
    font-family: monospace;
    font-size: 0.8rem;
    z-index: 10;
    pointer-events: none;
}

/* Spinner overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.7);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    color: white;
}

.spinner-lg {
    width: 3.5rem;
    height: 3.5rem;
}