:root {
    --primary-color: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;
    --success-color: #059669;
    --success-light: #10b981;
    --danger-color: #dc2626;
    --danger-light: #ef4444;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --white: #ffffff;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --transition: all 0.2s ease-in-out;
}

* {
    box-sizing: border-box;
}

body {
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
    min-height: 100vh;
    font-family: 'Inter', sans-serif;
    margin: 0;
    padding: 0;
    color: var(--gray-800);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.back-button {
    margin-bottom: 30px;
    margin-top: 20px;
}

.btn-outline-primary {
    background: var(--white);
    border: 1px solid var(--gray-300);
    color: var(--gray-700);
    border-radius: 8px;
    padding: 10px 20px;
    font-weight: 500;
    transition: var(--transition);
    text-decoration: none;
    box-shadow: var(--shadow);
}

.btn-outline-primary:hover {
    background: var(--gray-50);
    border-color: var(--gray-400);
    color: var(--gray-800);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

h1 {
    color: var(--gray-900);
    font-weight: 700;
    text-align: center;
    margin: 40px 0;
    font-size: 2.25rem;
}

h2 {
    color: var(--gray-800);
    font-weight: 600;
    margin-bottom: 30px;
}

h4, h5 {
    color: var(--gray-800);
    font-weight: 600;
}

.instructions-card, .card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    margin-bottom: 30px;
    transition: var(--transition);
}

.instructions-card:hover, .card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.instructions-card {
    padding: 32px;
}

.card-header {
    background: var(--gray-50);
    border-bottom: 1px solid var(--gray-200);
    padding: 20px 24px;
    border-radius: var(--border-radius-lg) var(--border-radius-lg) 0 0;
}

.card-body {
    padding: 24px;
}

.step-item {
    display: flex;
    align-items: start;
    margin-bottom: 20px;
}

.step-number {
    background: var(--primary-color);
    color: var(--white);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 16px;
    flex-shrink: 0;
    font-weight: 600;
    font-size: 0.875rem;
}

.step-item div:last-child {
    color: var(--gray-700);
    line-height: 1.6;
}

.upload-area {
    border: 2px dashed var(--gray-300);
    border-radius: var(--border-radius-lg);
    padding: 48px 32px;
    text-align: center;
    margin-bottom: 40px;
    background: var(--white);
    transition: var(--transition);
}

.upload-area.dragover, .upload-area:hover {
    border-color: var(--primary-color);
    background: var(--gray-50);
}

.upload-area h4 {
    color: var(--gray-800);
    margin-bottom: 12px;
    font-weight: 600;
}

.upload-area p {
    color: var(--gray-600);
    margin-bottom: 24px;
}

.upload-icon {
    font-size: 4rem;
    color: var(--gray-400);
    margin-bottom: 30px;
    transition: var(--transition);
    display: inline-block;
}

.upload-area:hover .upload-icon {
    color: var(--primary-color);
}

.file-input {
    display: none;
}

.btn-primary {
    background: var(--primary-color);
    border: none;
    border-radius: 8px;
    padding: 12px 24px;
    font-weight: 600;
    transition: var(--transition);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    color: var(--white);
}

.btn-custom {
    background: var(--primary-color);
    border: none;
    border-radius: 8px;
    padding: 16px 32px;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    color: var(--white);
}

.btn-custom:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
    color: var(--white);
}

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

.btn-success {
    background: var(--success-color);
    border: none;
    border-radius: 8px;
    padding: 12px 24px;
    font-weight: 600;
    transition: var(--transition);
    color: var(--white);
    margin-bottom: 24px;
}

.btn-success:hover {
    background: var(--success-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    color: var(--white);
}

.btn-warning {
    background: #f59e0b;
    border: none;
    border-radius: 8px;
    padding: 12px 24px;
    font-weight: 600;
    transition: var(--transition);
    color: var(--white);
}

.btn-warning:hover {
    background: #d97706;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    color: var(--white);
}

.btn-edit {
    background: var(--white);
    border: 1px solid var(--gray-300);
    color: var(--gray-700);
    border-radius: 6px;
    padding: 8px 16px;
    font-size: 0.875rem;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
}

.btn-edit:hover {
    background: var(--gray-50);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.btn-edit.changed {
    background: #fef3c7;
    border-color: #f59e0b;
    color: #92400e;
}

.edit-controls {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid var(--gray-200);
}

.btn-close {
    background: none;
    border: none;
    font-size: 1.2rem;
    opacity: 0.6;
    cursor: pointer;
    margin-left: auto;
    padding: 0;
    color: inherit;
}

.btn-close:hover {
    opacity: 1;
}

.notification {
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-outline-secondary {
    background: var(--white);
    border: 1px solid var(--gray-300);
    color: var(--gray-600);
    border-radius: 6px;
    padding: 6px 16px;
    font-size: 0.875rem;
    transition: var(--transition);
}

.btn-outline-secondary:hover {
    background: var(--gray-50);
    border-color: var(--gray-400);
    color: var(--gray-700);
}

.form-group {
    margin-bottom: 20px;
}

.form-select, .form-control {
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 8px;
    color: var(--gray-800);
    padding: 12px 16px;
    font-size: 0.875rem;
    transition: var(--transition);
}

.form-select:focus, .form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    outline: none;
}

.form-select option {
    background: var(--white);
    color: var(--gray-800);
}

label {
    color: var(--gray-700);
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 0.875rem;
}

.alert {
    border-radius: var(--border-radius);
    border: 1px solid;
    padding: 16px 20px;
    margin-bottom: 20px;
}

.alert-danger {
    background: #fef2f2;
    color: var(--danger-color);
    border-color: #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: var(--success-color);
    border-color: #bbf7d0;
}

.alert-info {
    background: #eff6ff;
    color: var(--primary-color);
    border-color: #dbeafe;
}

.badge {
    padding: 4px 12px;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 6px;
}

.bg-primary {
    background: var(--primary-color) !important;
    color: var(--white);
}

.bg-success {
    background: var(--success-color) !important;
    color: var(--white);
}

.bg-danger {
    background: var(--danger-color) !important;
    color: var(--white);
}

.comparison-container {
    background: var(--white);
    padding: 24px;
    margin-bottom: 32px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-200);
    transition: var(--transition);
}

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

.comparison-container.border-success {
    border-left: 4px solid var(--success-color);
}

.comparison-container.border-danger {
    border-left: 4px solid var(--danger-color);
}

.image-pair {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.image-wrapper {
    flex: 1;
    max-width: 45%;
    min-width: 300px;
}

.comparison-image {
    width: 100%;
    height: auto;
    max-height: 350px;
    object-fit: contain;
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.comparison-image:hover {
    box-shadow: var(--shadow-md);
}

.similarity-score {
    text-align: center;
    font-size: 1rem;
    padding: 16px;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    margin-top: 16px;
    border: 1px solid var(--gray-200);
}

.image-label {
    text-align: center;
    margin-top: 8px;
    color: var(--gray-600);
    font-weight: 500;
    font-size: 0.875rem;
}

.spinner-border {
    color: var(--primary-color);
}

/* Range Slider Styles */
.range-slider {
    position: relative;
    width: 100%;
    height: 50px;
    margin: 16px 0;
}

.range-slider .track {
    position: absolute;
    width: 100%;
    height: 6px;
    background: var(--gray-200);
    top: 50%;
    transform: translateY(-50%);
    border-radius: 3px;
}

.range-slider .range {
    position: absolute;
    height: 6px;
    background: var(--primary-color);
    top: 50%;
    transform: translateY(-50%);
    border-radius: 3px;
}

.range-slider .thumb {
    position: absolute;
    width: 20px;
    height: 20px;
    background: var(--white);
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    cursor: pointer;
    z-index: 2;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.range-slider .thumb:hover {
    box-shadow: var(--shadow-md);
    transform: translate(-50%, -50%) scale(1.1);
}

.range-slider .thumb.left {
    left: 0;
}

.range-slider .thumb.right {
    right: 0;
}

.range-values {
    display: flex;
    justify-content: space-between;
    margin-top: 12px;
    font-size: 0.875rem;
    color: var(--gray-600);
    font-weight: 500;
}

/* Icons */
.fa-info-circle, .fa-filter, .fa-eye, .fa-percentage {
    color: var(--primary-color);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    h1 {
        font-size: 1.875rem;
        margin: 24px 0;
    }

    .instructions-card, .card {
        padding: 20px 16px;
    }

    .upload-area {
        padding: 32px 20px;
    }

    .image-wrapper {
        max-width: 100%;
        min-width: auto;
    }

    .image-pair {
        flex-direction: column;
        gap: 16px;
    }

    .comparison-container {
        padding: 16px;
        margin-bottom: 24px;
    }
}

/* Utilities */
#reportContainer {
    margin-top: 32px;
}

.d-none {
    display: none !important;
}

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

.text-end {
    text-align: end;
}

.ms-2 {
    margin-left: 0.5rem;
}

.me-1, .me-2 {
    margin-right: 0.5rem;
}

.mb-0, .mb-3, .mb-4 {
    margin-bottom: 1rem;
}

.mt-2, .mt-3 {
    margin-top: 0.75rem;
}

.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}