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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --error-color: #ef4444;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    flex: 1;
    width: 100%;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 2rem;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Tab Navigation */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    background: var(--surface);
    padding: 0.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    flex-wrap: wrap;
}

.tab-btn {
    flex: 1;
    min-width: 120px;
    padding: 0.875rem 1rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.tab-btn:hover {
    background: var(--background);
    color: var(--text-primary);
}

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

/* Tab Content */
.tab-content {
    display: none;
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Input Groups */
.input-group,
.output-group {
    margin-bottom: 1rem;
    position: relative;
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

textarea {
    width: 100%;
    min-height: 150px;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    resize: vertical;
    transition: border-color 0.2s ease;
    background: var(--surface);
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

textarea[readonly] {
    background: var(--background);
}

/* Buttons */
.actions {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.primary-btn,
.secondary-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

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

.primary-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

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

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

.copy-btn {
    position: absolute;
    top: 2.5rem;
    right: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.copy-btn:hover {
    background: var(--background);
    border-color: var(--primary-color);
}

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

/* File Upload Area */
.file-upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
    transition: all 0.2s ease;
    margin-bottom: 1rem;
    background: var(--background);
}

.file-upload-area:hover,
.file-upload-area.dragover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.file-input-label {
    display: inline-block;
    margin: 1rem 0;
    cursor: pointer;
}

.file-name {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Options */
.options {
    margin-bottom: 1rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-weight: normal;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

/* Image Preview */
.image-preview-container {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.image-preview-container.hidden {
    display: none;
}

.image-preview {
    background: var(--background);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 1rem;
    text-align: center;
    max-height: 400px;
    overflow: auto;
}

.image-preview img {
    max-width: 100%;
    max-height: 350px;
    object-fit: contain;
    border-radius: var(--radius-sm);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-primary);
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    transition: all 0.3s ease;
}

.toast.hidden {
    opacity: 0;
    visibility: hidden;
    transform: translateX(-50%) translateY(20px);
}

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

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

/* Footer */
footer {
    background: var(--surface);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem;
    text-align: center;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem 0.75rem;
    }

    .logo-container {
        flex-direction: column;
        gap: 0.5rem;
    }

    h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .tabs {
        flex-direction: column;
    }

    .tab-btn {
        min-width: 100%;
    }

    .tab-content {
        padding: 1rem;
    }

    textarea {
        min-height: 120px;
        font-size: 0.85rem;
    }

    .actions {
        flex-direction: column;
    }

    .primary-btn,
    .secondary-btn {
        width: 100%;
    }

    .copy-btn {
        position: static;
        width: 100%;
        justify-content: center;
        margin-top: 0.5rem;
    }

    .file-upload-area {
        padding: 1.5rem 1rem;
    }

    .upload-icon {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.25rem;
    }

    .tab-btn {
        padding: 0.75rem;
        font-size: 0.9rem;
    }

    textarea {
        min-height: 100px;
        padding: 0.75rem;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --background: #0f172a;
        --surface: #1e293b;
        --text-primary: #f1f5f9;
        --text-secondary: #94a3b8;
        --border-color: #334155;
    }

    textarea {
        color: var(--text-primary);
    }

    .copy-btn {
        background: var(--surface);
        color: var(--text-primary);
    }

    .file-upload-area {
        background: var(--surface);
    }

    .file-upload-area:hover,
    .file-upload-area.dragover {
        background: rgba(99, 102, 241, 0.1);
    }
}