:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-card: #1e1e1e;
    --border-color: #333;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --accent-color: #8b5cf6;
    --accent-hover: #7c3aed;
    --accent-secondary: #a855f7;
    --error-color: #f44336;
    --success-color: #00ff88;
    --upload-bg: #252525;
    --upload-hover: #2a2a2a;
    --glass-bg: rgba(255, 255, 255, 0.02);
    --glass-border: rgba(255, 255, 255, 0.1);
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    position: relative;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(ellipse at top, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.container {
    position: relative;
    z-index: 1;
    flex: 1 0 auto;
    padding-bottom: 2rem;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    backdrop-filter: blur(20px);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.05);
    animation: slideInUp 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
    opacity: 0.5;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 20px;
    padding: 3.5rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--upload-bg);
    min-height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

.upload-area::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, transparent, rgba(139, 92, 246, 0.03), transparent);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--accent-color);
    background: var(--upload-hover);
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(139, 92, 246, 0.15);
}

.upload-area:hover::before,
.upload-area.dragover::before {
    opacity: 1;
}

.upload-area.dragover {
    transform: scale(1.02);
    border-style: solid;
}

.upload-icon {
    font-size: 4.5rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    animation: float 3s ease-in-out infinite;
    filter: drop-shadow(0 0 20px rgba(139, 92, 246, 0.3));
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-12px); }
}

.upload-area h5 {
    font-weight: 700;
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.preview {
    max-width: 100%;
    max-height: 400px;
    margin: 2rem 0;
    display: none;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
    border: 1px solid var(--glass-border);
}

.btn {
    border-radius: 14px;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.6s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 8px 25px rgba(139, 92, 246, 0.3);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(139, 92, 246, 0.4);
    background: linear-gradient(135deg, var(--accent-hover), var(--accent-color));
}

.btn-primary:disabled {
    background: linear-gradient(135deg, var(--border-color), #444);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-color);
    color: var(--text-primary);
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #00e07a);
    border: none;
    color: #000;
    font-weight: 700;
    box-shadow: 0 8px 25px rgba(0, 255, 136, 0.3);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px rgba(0, 255, 136, 0.4);
    background: linear-gradient(135deg, #00e07a, var(--success-color));
}

.alert-result {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: 16px;
    backdrop-filter: blur(15px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.alert-danger {
    background: rgba(244, 67, 54, 0.1);
    color: var(--error-color);
    border: 1px solid rgba(244, 67, 54, 0.3);
    border-radius: 12px;
    backdrop-filter: blur(10px);
}

.spinner {
    width: 1.25rem;
    height: 1.25rem;
    display: none;
    margin-right: 0.75rem;
    color: var(--accent-color);
}

h1 {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 900;
    font-size: 3.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 0 30px rgba(139, 92, 246, 0.3);
}

.text-muted {
    color: var(--text-secondary) !important;
    opacity: 0.9;
}

/* Improve contrast for compression settings */
#imageInfo h6 {
    color: var(--text-primary);
    font-weight: 700;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
    opacity: 0.95;
}

#compressionValue {
    color: var(--accent-color);
    font-weight: 700;
    font-size: 1.1em;
    margin-left: 5px;
}

.form-label {
    color: var(--text-primary);
    font-weight: 600;
    opacity: 0.95;
}

.form-range::-webkit-slider-thumb {
    background: var(--accent-color);
}

.form-range::-moz-range-thumb {
    background: var(--accent-color);
}

.info-stat {
    border-right: 1px solid var(--border-color);
    padding: 1rem;
    transition: all 0.3s ease;
}

.info-stat:last-child {
    border-right: none;
}

.info-stat:hover {
    background: rgba(139, 92, 246, 0.05);
    border-radius: 8px;
}

.info-stat small {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.info-stat span {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-color);
}

.savings-highlight {
    background: linear-gradient(135deg, rgba(0, 255, 136, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px solid rgba(0, 255, 136, 0.2);
    border-radius: 12px;
    padding: 1rem;
    margin-top: 1.5rem;
    position: relative;
    overflow: hidden;
}

.savings-highlight::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--success-color), var(--accent-color));
}

.savings-highlight strong {
    font-size: 1.3rem;
    background: linear-gradient(135deg, var(--success-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

footer {
    background: rgba(0, 0, 0, 0.4);
    border-top: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    margin-top: auto;
    width: 100%;
    position: relative;
    z-index: 1;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* Custom Toggle Switches */
.form-switch .form-check-input {
    width: 3em;
    height: 1.5em;
    margin-left: -2.5em;
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-color);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%23b0b0b0'/%3e%3c/svg%3e");
    background-position: left center;
    border-radius: 2em;
    transition: all 0.25s ease-in-out;
    cursor: pointer;
    margin-top: 0.25em;
}

.form-switch .form-check-input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 0.25rem rgba(139, 92, 246, 0.25);
}

.form-switch .form-check-input:checked {
    background-color: var(--accent-color);
    border-color: var(--accent-color);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%23fff'/%3e%3c/svg%3e");
    background-position: right center;
}

.form-switch .form-check-label {
    color: var(--text-primary) !important;
    font-weight: 500;
    margin-left: 0.5rem;
    opacity: 0.95;
    cursor: pointer;
    transition: all 0.2s ease;
    padding-top: 0.25em;
    display: block;
}

.form-switch .form-check-label:hover {
    opacity: 1;
}

.form-switch .form-check-input:checked ~ .form-check-label {
    color: var(--text-primary) !important;
}

.processing {
    animation: pulse 2s ease-in-out infinite;
}

.text-gradient {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: glow 2s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { text-shadow: 0 0 20px rgba(139, 92, 246, 0.5); }
    50% { text-shadow: 0 0 30px rgba(139, 92, 246, 0.8); }
}

/* Responsive improvements */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }
    
    .upload-area {
        padding: 2rem 1rem;
        min-height: 220px;
    }
    
    .upload-icon {
        font-size: 3rem;
    }
    
    .card-body {
        padding: 1.5rem !important;
    }
    
    .info-stat {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 0.75rem;
    }
    
    .info-stat:last-child {
        border-bottom: none;
    }
}

/* Mobile Optimizations */
@media (max-width: 576px) {
    .upload-shortcuts {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .info-stat {
        padding: 0.5rem;
    }
    
    .btn-lg {
        padding: 0.75rem 1.5rem;
        font-size: 1rem;
    }
    
    .savings-highlight strong {
        font-size: 1.1rem;
    }

    .btn-group {
        flex-wrap: wrap;
    }

    .btn-group .btn {
        flex: 1 1 auto;
        white-space: nowrap;
    }

    .preview {
        max-height: 300px;
    }
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
    border-radius: 4px;
}        ::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, var(--accent-hover), var(--accent-color));
}

/* File Queue Styles */
.file-item {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    margin-bottom: 0.5rem;
    padding: 0.75rem;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.file-item:hover {
    border-color: var(--accent-color);
    transform: translateY(-1px);
}

.file-item .progress {
    height: 4px;
    border-radius: 2px;
    background: var(--bg-secondary);
}
  /* Image Comparison Slider */
.comparison-slider {
    position: relative;
    width: 100%;
    max-width: 800px;
    margin: 2rem auto;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
    cursor: col-resize;
}

.comparison-slider img {
    width: 100%;
    height: auto;
    display: block;
    max-height: 600px;
    object-fit: contain;
}

.comparison-overlay {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 50%;
    overflow: hidden;
    border-right: 2px solid var(--accent-color);
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.3);
    backdrop-filter: brightness(1.1);
}

.comparison-handle {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    height: 48px;
    width: 48px;
    background: var(--accent-color);
    border: 2px solid white;
    border-radius: 50%;
    cursor: ew-resize;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.4);
    transition: transform 0.2s ease;
}

.comparison-handle:hover {
    transform: translate(-50%, -50%) scale(1.1);
}

.comparison-handle::before {
    content: '↔';
    font-size: 24px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.comparison-label {
    position: absolute;
    bottom: 1rem;
    padding: 0.5rem 1rem;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    border-radius: 20px;
    font-size: 0.8rem;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.comparison-label.original {
    right: 1rem;
}

.comparison-label.compressed {
    left: 1rem;
}

/* Preview Container Styles */
.preview-container {
    position: relative;
}

.preview-overlay {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.preview-container:hover .preview-overlay {
    opacity: 1;
}

/* Loading Animation */
.loader-ring {
    display: inline-block;
    width: 50px;
    height: 50px;
    border: 3px solid transparent;
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: loader-spin 1s linear infinite;
}

.preview-loader {
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    border-radius: 16px;
    z-index: 1;
}

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

/* Upload Shortcuts */
.upload-shortcuts {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    margin-top: 1.5rem !important;
}

.badge.bg-dark {
    background: var(--bg-secondary) !important;
    border: 1px solid var(--border-color);
    font-family: monospace;
    font-size: 0.7rem;
    padding: 0.25rem 0.5rem;
}

/* Mobile Optimizations */
@media (max-width: 576px) {
    .upload-shortcuts {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .info-stat {
        padding: 0.5rem;
    }
    
    .btn-lg {
        padding: 0.75rem 1.5rem;
        font-size: 1rem;
    }
    
    .savings-highlight strong {
        font-size: 1.1rem;
    }

    .btn-group {
        flex-wrap: wrap;
    }

    .btn-group .btn {
        flex: 1 1 auto;
        white-space: nowrap;
    }

    .preview {
        max-height: 300px;
    }
}