/* ==========================================================================
   Compress-It - CSS Styles
   Modern, responsive styles for the image compression app
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Variables & Reset
   -------------------------------------------------------------------------- */
:root {
    /* Colors */
    --color-primary: #6366f1;
    --color-primary-dark: #4f46e5;
    --color-primary-light: #818cf8;
    --color-success: #10b981;
    --color-success-light: #d1fae5;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-error-light: #fee2e2;
    
    /* Neutrals */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Container */
    --container-max-width: 1200px;
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-gray-800);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
    min-height: 100vh;
}

/* --------------------------------------------------------------------------
   Layout
   -------------------------------------------------------------------------- */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.main {
    flex: 1;
    padding: var(--spacing-6);
    max-width: var(--container-max-width);
    margin: 0 auto;
    width: 100%;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.header {
    background: var(--color-white);
    border-bottom: 1px solid var(--color-gray-200);
    padding: var(--spacing-4) var(--spacing-6);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    max-width: var(--container-max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    text-decoration: none;
    color: var(--color-gray-900);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--color-primary);
}

.logo-text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.nav-badge {
    background: var(--color-success-light);
    color: var(--color-success);
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
    text-align: center;
    padding: var(--spacing-8) var(--spacing-4);
}

.hero h1 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-3);
    letter-spacing: -0.02em;
}

.hero p {
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* --------------------------------------------------------------------------
   Upload Section
   -------------------------------------------------------------------------- */
.upload-section {
    margin-bottom: var(--spacing-8);
}

.upload-area {
    background: var(--color-white);
    border: 2px dashed var(--color-gray-300);
    border-radius: var(--radius-xl);
    padding: var(--spacing-12);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--color-primary);
    background: linear-gradient(135deg, #f8faff 0%, #f0f4ff 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.upload-area.dragover {
    border-color: var(--color-primary-dark);
    border-style: solid;
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-3);
}

.upload-icon {
    width: 64px;
    height: 64px;
    color: var(--color-primary);
    margin-bottom: var(--spacing-2);
}

.upload-content h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-gray-800);
}

.upload-content p {
    color: var(--color-gray-500);
}

.upload-hint {
    font-size: var(--font-size-sm);
    color: var(--color-gray-400) !important;
    margin-top: var(--spacing-2);
}

/* --------------------------------------------------------------------------
   Settings Section
   -------------------------------------------------------------------------- */
.settings-section {
    margin-bottom: var(--spacing-8);
}

.settings-card {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-8);
    box-shadow: var(--shadow-md);
}

.settings-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-6);
    color: var(--color-gray-900);
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-6);
    margin-bottom: var(--spacing-8);
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2);
}

.setting-group label {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-gray-700);
}

/* Slider */
.slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    border-radius: var(--radius-full);
    background: var(--color-gray-200);
    outline: none;
    transition: var(--transition-fast);
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: var(--transition-fast);
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.1);
    background: var(--color-primary-dark);
}

.slider::-moz-range-thumb {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--color-primary);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-md);
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    font-size: var(--font-size-xs);
    color: var(--color-gray-400);
    margin-top: var(--spacing-1);
}

/* Select */
.select {
    width: 100%;
    padding: var(--spacing-3) var(--spacing-4);
    font-size: var(--font-size-base);
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-md);
    background: var(--color-white);
    color: var(--color-gray-800);
    cursor: pointer;
    transition: var(--transition-fast);
}

.select:hover {
    border-color: var(--color-gray-400);
}

.select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* Input */
.input {
    width: 100%;
    padding: var(--spacing-3) var(--spacing-4);
    font-size: var(--font-size-base);
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-md);
    background: var(--color-white);
    color: var(--color-gray-800);
    transition: var(--transition-fast);
}

.input:hover {
    border-color: var(--color-gray-400);
}

.input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input::placeholder {
    color: var(--color-gray-400);
}

/* Settings Actions */
.settings-actions {
    display: flex;
    justify-content: center;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-6);
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--radius-lg);
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn svg {
    width: 20px;
    height: 20px;
}

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

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

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

.btn-secondary {
    background: var(--color-gray-100);
    color: var(--color-gray-700);
}

.btn-secondary:hover {
    background: var(--color-gray-200);
}

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

.btn-success:hover {
    background: #059669;
}

.btn-text {
    background: transparent;
    color: var(--color-gray-500);
    padding: var(--spacing-2) var(--spacing-3);
}

.btn-text:hover {
    color: var(--color-gray-700);
    background: var(--color-gray-100);
}

.btn-large {
    padding: var(--spacing-4) var(--spacing-8);
    font-size: var(--font-size-lg);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

/* --------------------------------------------------------------------------
   Progress Section
   -------------------------------------------------------------------------- */
.progress-section {
    margin-bottom: var(--spacing-8);
}

.progress-card {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-6);
    box-shadow: var(--shadow-md);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-4);
}

.progress-title {
    font-weight: 600;
    color: var(--color-gray-800);
}

.progress-count {
    color: var(--color-gray-500);
    font-size: var(--font-size-sm);
}

.progress-bar {
    height: 8px;
    background: var(--color-gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-full);
    width: 0%;
    transition: width var(--transition-base);
}

/* --------------------------------------------------------------------------
   Results Section
   -------------------------------------------------------------------------- */
.results-section {
    margin-bottom: var(--spacing-8);
}

.results-header {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-8);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-6);
}

.results-summary h2 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-6);
}

.summary-stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-6);
}

.stat {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-1);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-gray-500);
}

.stat-value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-gray-900);
}

.stat-arrow {
    font-size: var(--font-size-2xl);
    color: var(--color-gray-400);
}

.stat-highlight .stat-value {
    color: var(--color-success);
    font-size: var(--font-size-2xl);
}

.results-actions {
    display: flex;
    gap: var(--spacing-4);
    flex-wrap: wrap;
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-6);
}

.result-card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

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

.result-preview {
    position: relative;
    aspect-ratio: 16/10;
    background: var(--color-gray-100);
    overflow: hidden;
    cursor: pointer;
}

.result-preview img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.result-preview-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

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

.result-preview-overlay span {
    color: var(--color-white);
    font-weight: 600;
    background: rgba(0, 0, 0, 0.5);
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--radius-md);
}

.result-info {
    padding: var(--spacing-4);
}

.result-name {
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-2);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.result-stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    margin-bottom: var(--spacing-3);
    font-size: var(--font-size-sm);
}

.result-original {
    color: var(--color-gray-500);
    text-decoration: line-through;
}

.result-compressed {
    color: var(--color-gray-800);
    font-weight: 600;
}

.result-savings {
    background: var(--color-success-light);
    color: var(--color-success);
    padding: var(--spacing-1) var(--spacing-2);
    border-radius: var(--radius-sm);
    font-weight: 600;
}

.result-actions {
    display: flex;
    gap: var(--spacing-2);
}

.result-actions .btn {
    flex: 1;
    padding: var(--spacing-2) var(--spacing-3);
    font-size: var(--font-size-sm);
}

/* --------------------------------------------------------------------------
   Files Section
   -------------------------------------------------------------------------- */
.files-section {
    margin-bottom: var(--spacing-8);
}

.files-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-4);
}

.files-header h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-gray-800);
}

.files-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.file-item {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-4);
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.file-item:hover {
    box-shadow: var(--shadow-md);
}

.file-thumb {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    background: var(--color-gray-100);
    overflow: hidden;
    flex-shrink: 0;
}

.file-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 600;
    color: var(--color-gray-800);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: var(--font-size-sm);
    color: var(--color-gray-500);
}

.file-remove {
    background: var(--color-gray-100);
    border: none;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--color-gray-500);
    transition: var(--transition-fast);
}

.file-remove:hover {
    background: var(--color-error-light);
    color: var(--color-error);
}

/* --------------------------------------------------------------------------
   Modal
   -------------------------------------------------------------------------- */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-4);
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--color-white);
    border-radius: var(--radius-xl);
    max-width: 1000px;
    width: 100%;
    max-height: 90vh;
    overflow: auto;
    box-shadow: var(--shadow-xl);
}

.modal-close {
    position: absolute;
    top: var(--spacing-4);
    right: var(--spacing-4);
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    border: none;
    background: var(--color-gray-100);
    color: var(--color-gray-600);
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
    z-index: 10;
}

.modal-close:hover {
    background: var(--color-gray-200);
    color: var(--color-gray-800);
}

.preview-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4);
    padding: var(--spacing-8);
}

.preview-panel {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.preview-panel h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-gray-800);
    text-align: center;
}

.preview-image-wrapper {
    background: var(--color-gray-100);
    border-radius: var(--radius-lg);
    padding: var(--spacing-4);
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.preview-image-wrapper img {
    max-width: 100%;
    max-height: 400px;
    object-fit: contain;
}

.preview-size {
    text-align: center;
    font-weight: 600;
    color: var(--color-gray-600);
}

/* --------------------------------------------------------------------------
   Toast Notifications
   -------------------------------------------------------------------------- */
.toast-container {
    position: fixed;
    bottom: var(--spacing-6);
    right: var(--spacing-6);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
    z-index: 1100;
}

.toast {
    background: var(--color-gray-800);
    color: var(--color-white);
    padding: var(--spacing-4) var(--spacing-6);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    animation: slideIn 0.3s ease;
    max-width: 400px;
}

.toast.success {
    background: var(--color-success);
}

.toast.error {
    background: var(--color-error);
}

.toast.warning {
    background: var(--color-warning);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    background: var(--color-white);
    border-top: 1px solid var(--color-gray-200);
    padding: var(--spacing-6);
    text-align: center;
}

.footer-content p {
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-1);
}

.footer-note {
    font-size: var(--font-size-sm);
    color: var(--color-gray-400) !important;
}

/* --------------------------------------------------------------------------
   Loading States
   -------------------------------------------------------------------------- */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: inherit;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--color-gray-200);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* --------------------------------------------------------------------------
   Responsive Design
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
    .hero h1 {
        font-size: var(--font-size-2xl);
    }

    .hero p {
        font-size: var(--font-size-base);
    }

    .upload-area {
        padding: var(--spacing-8);
    }

    .upload-icon {
        width: 48px;
        height: 48px;
    }

    .settings-card,
    .results-header {
        padding: var(--spacing-6);
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .summary-stats {
        flex-direction: column;
        align-items: flex-start;
    }

    .stat-arrow {
        display: none;
    }

    .results-actions {
        flex-direction: column;
    }

    .results-actions .btn {
        width: 100%;
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .preview-container {
        grid-template-columns: 1fr;
        padding: var(--spacing-4);
    }

    .modal-content {
        margin: var(--spacing-4);
    }
}

@media (max-width: 480px) {
    .main {
        padding: var(--spacing-4);
    }

    .header-content {
        flex-direction: column;
        gap: var(--spacing-2);
    }

    .btn-large {
        padding: var(--spacing-3) var(--spacing-6);
        font-size: var(--font-size-base);
    }

    .file-item {
        flex-wrap: wrap;
    }

    .file-info {
        flex-basis: calc(100% - 72px);
    }
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */
.hidden {
    display: none !important;
}

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