/* CSS Variables for Modern Theming */
:root {
    --color-primary: #0F172A;
    --color-primary-hover: #1E293B;
    --color-accent: #3B82F6;
    --color-accent-hover: #2563EB;
    --color-secondary: #64748B;
    --color-secondary-hover: #475569;
    --color-tertiary: #E2E8F0;
    --color-success: #22C55E;
    --color-warning: #F59E0B;
    --color-error: #EF4444;
    --color-background: #FFFFFF;
    --color-background-alt: #F8FAFC;
    --color-surface: #FFFFFF;
    --color-text: #0F172A;
    --color-text-light: #64748B;
    --color-text-muted: #94A3B8;
    --color-border: #E2E8F0;
    --color-border-light: #F1F5F9;
    --spacing-unit: 8px;
    --border-radius-sm: 6px;
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-background-alt);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header */
header {
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 4);
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
    background-color: rgba(255, 255, 255, 0.95);
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-unit);
    letter-spacing: -0.02em;
}

.privacy-notice {
    font-size: 0.8125rem;
    color: var(--color-success);
    margin-bottom: calc(var(--spacing-unit) * 3);
    font-weight: 500;
    background-color: rgba(34, 197, 94, 0.08);
    padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius-sm);
    display: inline-block;
}

/* Progress Indicator */
#progress-indicator {
    display: flex;
    justify-content: center;
    gap: var(--spacing-unit);
    flex-wrap: wrap;
}

.step-indicator {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) * 0.75);
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 2);
    background-color: var(--color-background-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--color-text-light);
    transition: all var(--transition);
    cursor: default;
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    background-color: var(--color-border);
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-text-light);
    transition: all var(--transition);
}

.step-indicator.active {
    background-color: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

.step-indicator.active .step-number {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
}

.step-indicator.completed {
    background-color: var(--color-success);
    border-color: var(--color-success);
    color: white;
}

.step-indicator.completed .step-number {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
}

/* Main Content */
main {
    flex: 1;
    padding: calc(var(--spacing-unit) * 4);
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
}

/* Step Management */
.step {
    display: none;
    animation: fadeIn var(--transition-slow);
}

.step.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.step-content {
    background-color: var(--color-surface);
    border-radius: var(--border-radius-lg);
    padding: calc(var(--spacing-unit) * 4);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border-light);
}

.step-content h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-unit);
    color: var(--color-text);
    letter-spacing: -0.01em;
}

.instructions {
    color: var(--color-text-light);
    margin-bottom: calc(var(--spacing-unit) * 3);
    font-size: 0.9375rem;
}

/* Video and Image Containers */
.video-container,
.image-preview {
    position: relative;
    width: 100%;
    margin: 0 auto calc(var(--spacing-unit) * 3);
    border-radius: var(--border-radius);
    overflow: hidden;
}

#webcam,
#captured-photo,
canvas {
    width: 100%;
    border-radius: var(--border-radius);
    display: block;
}

#webcam {
    background-color: #1E293B;
    min-height: 400px;
    object-fit: cover;
}

#captured-photo {
    max-height: 480px;
    object-fit: contain;
    background-color: var(--color-background-alt);
}

canvas {
    max-height: 480px;
    background-color: var(--color-background-alt);
}

/* Error Messages */
.error-message {
    background-color: rgba(239, 68, 68, 0.08);
    color: var(--color-error);
    padding: calc(var(--spacing-unit) * 2);
    border-radius: var(--border-radius);
    margin-top: var(--spacing-unit);
    text-align: center;
    font-size: 0.875rem;
    font-weight: 500;
}

.error-message.hidden {
    display: none;
}

/* Loading Indicator */
.loading {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius);
}

.loading.hidden {
    display: none;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading p {
    margin-top: calc(var(--spacing-unit) * 2);
    color: var(--color-text-light);
    font-weight: 500;
    font-size: 0.875rem;
}

/* Buttons and Controls */
.controls {
    display: flex;
    gap: var(--spacing-unit);
    flex-wrap: wrap;
    justify-content: center;
    margin-top: calc(var(--spacing-unit) * 3);
}

.btn {
    padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 3);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-unit);
    min-width: 120px;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--color-accent);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--color-accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-secondary {
    background-color: var(--color-background-alt);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
    background-color: var(--color-border);
    border-color: var(--color-border);
}

.btn-tertiary {
    background-color: transparent;
    color: var(--color-text-light);
}

.btn-tertiary:hover:not(:disabled) {
    color: var(--color-text);
    background-color: var(--color-background-alt);
}

/* Color Selector */
.color-selector {
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.color-selector h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text);
}

.preset-colors {
    display: flex;
    gap: calc(var(--spacing-unit) * 1.5);
    flex-wrap: wrap;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.color-preset {
    width: 72px;
    height: 72px;
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 0.75rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text);
}

.color-preset:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.color-preset.active {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.custom-color {
    display: flex;
    align-items: center;
    gap: calc(var(--spacing-unit) * 1.5);
    flex-wrap: wrap;
}

.custom-color label {
    font-weight: 500;
    color: var(--color-text);
    font-size: 0.875rem;
}

.custom-color input[type="color"] {
    width: 48px;
    height: 36px;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    padding: 2px;
}

#color-value {
    font-family: 'SF Mono', 'Consolas', monospace;
    color: var(--color-text-light);
    font-size: 0.8125rem;
    background-color: var(--color-background-alt);
    padding: calc(var(--spacing-unit) * 0.5) calc(var(--spacing-unit) * 1);
    border-radius: var(--border-radius-sm);
}

/* Size Selector */
.size-selector {
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.size-selector label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-unit);
    color: var(--color-text);
    font-size: 0.875rem;
}

.size-selector select {
    width: 100%;
    padding: calc(var(--spacing-unit) * 1.5);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    font-size: 0.9375rem;
    background-color: var(--color-background);
    cursor: pointer;
    transition: all var(--transition-fast);
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748B' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 40px;
}

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

.size-selector select:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Crop Controls */
.crop-controls {
    margin-bottom: calc(var(--spacing-unit) * 3);
    padding: calc(var(--spacing-unit) * 2.5);
    background-color: var(--color-background-alt);
    border-radius: var(--border-radius);
}

.crop-controls h3 {
    font-size: 0.9375rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text);
}

.slider-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-unit);
    margin-bottom: calc(var(--spacing-unit) * 1.5);
}

.slider-group:last-child {
    margin-bottom: 0;
}

.crop-controls label {
    display: inline-block;
    font-weight: 500;
    color: var(--color-text);
    min-width: 90px;
    font-size: 0.875rem;
}

.crop-controls input[type="range"] {
    flex: 1;
    cursor: pointer;
    height: 6px;
    appearance: none;
    background-color: var(--color-border);
    border-radius: 3px;
}

.crop-controls input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 18px;
    height: 18px;
    background-color: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.crop-controls input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.15);
}

.crop-controls input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background-color: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

/* Crop Guide */
.crop-guide {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80%;
    height: 80%;
    border: 2px dashed rgba(59, 130, 246, 0.4);
    pointer-events: none;
    display: none;
    border-radius: var(--border-radius-sm);
}

.crop-guide.active {
    display: block;
}

.head-guide {
    position: absolute;
    top: 15%;
    left: 50%;
    transform: translateX(-50%);
    width: 50%;
    height: 55%;
    border: 2px solid rgba(34, 197, 94, 0.4);
    border-radius: 50%;
}

.eye-line {
    position: absolute;
    top: 45%;
    left: 10%;
    right: 10%;
    height: 2px;
    background-color: rgba(245, 158, 11, 0.4);
}

/* Photo Info */
.photo-info {
    margin-bottom: calc(var(--spacing-unit) * 3);
    padding: calc(var(--spacing-unit) * 2.5);
    background-color: var(--color-background-alt);
    border-radius: var(--border-radius);
}

.photo-info h3 {
    font-size: 0.9375rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 1.5);
    color: var(--color-text);
}

.photo-info p {
    margin-bottom: calc(var(--spacing-unit) * 0.75);
    color: var(--color-text-light);
    font-size: 0.875rem;
}

.photo-info p:last-child {
    margin-bottom: 0;
}

.photo-info strong {
    color: var(--color-text);
    font-weight: 500;
}

/* Footer */
footer {
    background-color: var(--color-background);
    border-top: 1px solid var(--color-border);
    padding: calc(var(--spacing-unit) * 3) calc(var(--spacing-unit) * 4);
    text-align: center;
    color: var(--color-text-light);
    font-size: 0.8125rem;
}

.footer-links {
    margin-top: var(--spacing-unit);
}

.footer-links a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-accent-hover);
}

/* Responsive Design */
@media (max-width: 1024px) {
    main {
        padding: calc(var(--spacing-unit) * 3);
    }
    
    .step-content {
        padding: calc(var(--spacing-unit) * 3);
    }
}

@media (max-width: 768px) {
    header {
        padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 2);
        position: relative;
    }
    
    header h1 {
        font-size: 1.25rem;
    }
    
    #progress-indicator {
        gap: calc(var(--spacing-unit) * 0.5);
    }
    
    .step-indicator {
        padding: calc(var(--spacing-unit)) calc(var(--spacing-unit) * 1.5);
        font-size: 0.75rem;
    }
    
    .step-number {
        width: 18px;
        height: 18px;
        font-size: 0.6875rem;
    }
    
    .video-container,
    .image-preview {
        max-width: 100%;
    }
    
    #webcam {
        min-height: 300px;
    }
    
    .controls {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .slider-group {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .crop-controls label {
        min-width: auto;
        margin-bottom: var(--spacing-unit);
    }
    
    .crop-controls input[type="range"] {
        width: 100%;
    }
}

@media (max-width: 640px) {
    main {
        padding: calc(var(--spacing-unit) * 2);
    }
    
    .step-content {
        padding: calc(var(--spacing-unit) * 2);
        border-radius: var(--border-radius);
    }
    
    .preset-colors {
        justify-content: center;
    }
    
    .color-preset {
        width: 64px;
        height: 64px;
        font-size: 0.6875rem;
    }
    
    .step-text {
        display: none;
    }
    
    .step-indicator {
        padding: var(--spacing-unit);
    }
    
    .step-number {
        width: 28px;
        height: 28px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles */
.btn:focus,
select:focus,
input:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.btn:focus:not(:focus-visible) {
    outline: none;
}

/* Print Styles */
@media print {
    header,
    footer,
    .controls {
        display: none;
    }
    
    .step-content {
        box-shadow: none;
        border: none;
    }
}