/* === RESET & BASE STYLES === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-solid: #667eea;
    --secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --secondary-solid: #f093fb;
    --accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
    --error: linear-gradient(135deg, #fc466b 0%, #3f5efb 100%);
    
    /* Neutral Colors */
    --white: #ffffff;
    --light-gray: #f8fafc;
    --gray: #64748b;
    --dark-gray: #334155;
    --black: #0f172a;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --border-radius-sm: 8px;
    --border-radius-md: 12px;
    --border-radius-lg: 16px;
    --border-radius-xl: 24px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #f8fafc;
    min-height: 100vh;
    color: var(--dark-gray);
    line-height: 1.6;
    overflow-x: hidden;
}

/* === UTILITY CLASSES === */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius-md);
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-normal);
    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, 0.2), transparent);
    transition: left var(--transition-normal);
}

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

.btn-primary {
    background: var(--primary);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: var(--white);
    color: var(--primary-solid);
    border: 2px solid transparent;
    box-shadow: var(--shadow-sm);
}

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

/* === CONTAINER === */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    position: relative;
    z-index: 1;
}

/* === MODAL === */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 1;
    visibility: visible;
    transition: all var(--transition-normal);
}

.modal.hidden {
    opacity: 0;
    visibility: hidden;
}

.modal-content {
    background: var(--white);
    border-radius: var(--border-radius-xl);
    padding: 0;
    max-width: 480px;
    width: 90%;
    box-shadow: var(--shadow-xl);
    transform: scale(1);
    transition: transform var(--transition-normal);
    overflow: hidden;
}

.modal.hidden .modal-content {
    transform: scale(0.9);
}

.modal-header {
    background: var(--white);
    color: var(--dark-gray);
    padding: var(--spacing-xl) var(--spacing-lg);
    text-align: center;
    border-bottom: 1px solid #e2e8f0;
}

.modal-header h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.modal-header p {
    opacity: 0.9;
    font-size: 1rem;
}

.modal-body {
    padding: var(--spacing-xl) var(--spacing-lg);
}

.input-group {
    position: relative;
    margin-bottom: var(--spacing-md);
}

.input-group i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray);
    z-index: 2;
}

.input-group input {
    width: 100%;
    padding: 16px 56px 16px 48px;
    border: 2px solid #e2e8f0;
    border-radius: var(--border-radius-md);
    font-size: 1rem;
    transition: all var(--transition-normal);
    background: var(--white);
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-solid);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.password-toggle {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--gray);
    cursor: pointer;
    padding: 8px;
    border-radius: var(--border-radius-sm);
    transition: color var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.password-toggle:hover {
    color: var(--primary-solid);
}

.api-info {
    background: var(--light-gray);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    font-size: 0.9rem;
    color: var(--gray);
}

.api-info a {
    color: var(--primary-solid);
    text-decoration: none;
    font-weight: 500;
}

.api-info a:hover {
    text-decoration: underline;
}

.modal-footer {
    padding: 0 var(--spacing-lg) var(--spacing-xl);
}

.modal-footer .btn {
    width: 100%;
    justify-content: center;
    padding: 16px;
    font-size: 1.1rem;
}

/* === HEADER === */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-2xl);
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid #e2e8f0;
    box-shadow: var(--shadow-sm);
}

.logo h1 {
    font-size: 2rem;
    font-weight: 600;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-xs);
}

.logo p {
    color: var(--gray);
    font-size: 1rem;
}

.settings-btn {
    background: var(--light-gray);
    border: 1px solid #e2e8f0;
    color: var(--gray);
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.settings-btn:hover {
    background: #e2e8f0;
    color: var(--dark-gray);
}

/* === UPLOAD SECTION === */
.upload-section {
    margin-bottom: var(--spacing-2xl);
}

.upload-area {
    background: var(--white);
    border: 3px dashed #e2e8f0;
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-2xl);
    text-align: center;
    transition: all var(--transition-normal);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.upload-area::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary);
    opacity: 0;
    transition: opacity var(--transition-normal);
    z-index: 1;
}

.upload-area:hover {
    border-color: var(--primary-solid);
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.upload-area:hover::before {
    opacity: 0.05;
}

.upload-area.dragover {
    border-color: var(--primary-solid);
    background: rgba(102, 126, 234, 0.05);
    transform: scale(1.02);
}

.upload-content {
    position: relative;
    z-index: 2;
}

.upload-icon {
    font-size: 3rem;
    color: var(--gray);
    margin-bottom: var(--spacing-md);
}

.upload-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-xs);
}

.upload-content p {
    color: var(--gray);
    margin-bottom: var(--spacing-xs);
}

.file-types {
    font-size: 0.9rem;
    color: var(--gray);
    margin-bottom: var(--spacing-lg) !important;
}

/* === COMPARISON SECTION === */
.comparison-section {
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
}

.comparison-section.show {
    opacity: 1;
    transform: translateY(0);
}

.comparison-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.image-card {
    background: var(--white);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.image-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--dark-gray);
}

.image-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.card-header {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.card-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--dark-gray);
}

.image-container {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background: var(--light-gray);
    display: flex;
    align-items: center;
    justify-content: center;
}

.image-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-normal);
}

.image-container:hover img {
    transform: scale(1.05);
}

/* === VS INDICATOR === */
.vs-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.vs-circle {
    width: 60px;
    height: 60px;
    background: var(--dark-gray);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-weight: 600;
    font-size: 1.2rem;
    box-shadow: var(--shadow-md);
}

.lightning {
    font-size: 1.5rem;
    color: var(--gray);
}

/* === LOADING SPINNER === */
.loading-spinner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-left: 4px solid var(--primary-solid);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-spinner p {
    color: var(--gray);
    font-size: 0.9rem;
}

/* === RESULT DESCRIPTION === */
.result-description {
    background: var(--white);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    text-align: center;
    opacity: 0;
    transform: translateY(20px);
    transition: all var(--transition-slow);
}

.result-description.show {
    opacity: 1;
    transform: translateY(0);
}

.description-content {
    margin-bottom: var(--spacing-xl);
}

.description-content h4 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-md);
}

.description-content p {
    font-size: 1.1rem;
    color: var(--gray);
    line-height: 1.7;
}

.action-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* === FOOTER === */
.footer {
    text-align: center;
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-lg);
    color: var(--gray);
    font-size: 0.9rem;
}

/* === TOASTS === */
.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--white);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    z-index: 1001;
    transform: translateX(400px);
    transition: transform var(--transition-normal);
    max-width: 400px;
}

.toast.show {
    transform: translateX(0);
}

.toast-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
}

.error-toast {
    border-left: 4px solid #fc466b;
}

.error-toast i {
    color: #fc466b;
}

.success-toast {
    border-left: 4px solid #11998e;
}

.success-toast i {
    color: #11998e;
}

.toast-close {
    background: none;
    border: none;
    color: var(--gray);
    cursor: pointer;
    padding: 4px;
    border-radius: var(--border-radius-sm);
    transition: color var(--transition-fast);
}

.toast-close:hover {
    color: var(--dark-gray);
}

/* === RESPONSIVE DESIGN === */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }
    
    .header {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .comparison-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .vs-indicator {
        order: -1;
    }
    
    .image-container {
        width: 150px;
        height: 150px;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .action-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    
    .modal-content {
        margin: var(--spacing-md);
        width: calc(100% - 2rem);
    }
    
    .toast {
        right: var(--spacing-md);
        left: var(--spacing-md);
        max-width: none;
    }
}

@media (max-width: 480px) {
    .upload-area {
        padding: var(--spacing-lg);
    }
    
    .upload-icon {
        font-size: 2.5rem;
    }
    
    .upload-content h3 {
        font-size: 1.25rem;
    }
    
    .image-container {
        width: 120px;
        height: 120px;
    }
    
    .vs-circle {
        width: 50px;
        height: 50px;
        font-size: 1rem;
    }
}