* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #059669;
    --success-hover: #047857;
    --error-color: #dc2626;
    --text-color: #1f2937;
    --text-secondary: #4b5563;
    --border-color: #e5e7eb;
    --background-color: #f9fafb;
    --card-background: #ffffff;
    --shadow-color: rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    min-height: 100vh;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    color: var(--text-color);
    line-height: 1.5;
    font-size: 14px;
    padding: 1rem;
}

.container {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 10px 25px var(--shadow-color);
    width: 100%;
    max-width: 800px;
    /*margin: 0 auto;*/
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 2rem;
    align-items: start;
}

@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

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

.logo {
    width: 48px;
    height: 48px;
    filter: drop-shadow(0 2px 4px var(--shadow-color));
}

h1 {
    color: var(--text-color);
    text-align: center;
    margin-bottom: 0.5rem;
    font-size: 1.75rem;
    font-weight: 600;
}

.description {
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 1.75rem;
    font-size: 0.95rem;
}

.upload-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-bottom: 1rem;
}

.file-input-container {
    position: relative;
}

input[type="file"] {
    position: absolute;
    width: 0.1px;
    height: 0.1px;
    opacity: 0;
    overflow: hidden;
    z-index: -1;
}

.file-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem;
    background: var(--background-color);
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.file-label:hover {
    border-color: var(--primary-color);
    background: #f0f7ff;
}

.file-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.file-button {
    background: var(--primary-color);
    color: white;
    padding: 0.6rem 1.25rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background 0.2s ease;
}

.file-button:hover {
    background: var(--primary-hover);
}

.file-preview {
    display: none;
    margin-top: 0.75rem;
    padding: 1.25rem;
    background: var(--background-color);
    border-radius: 8px;
}

.preview-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 0.75rem;
}

#imagePreview {
    max-width: 100%;
    max-height: 250px;
    border-radius: 6px;
    box-shadow: 0 2px 4px var(--shadow-color);
}

.pdf-preview {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    padding: 1.5rem;
    background: var(--card-background);
    border-radius: 6px;
    box-shadow: 0 2px 4px var(--shadow-color);
}

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

.pdf-name {
    font-size: 0.95rem;
    color: var(--text-color);
}

.file-info {
    background: var(--card-background);
    padding: 0.875rem;
    border-radius: 6px;
    font-size: 0.875rem;
}

.file-info p {
    margin: 0.375rem 0;
    color: var(--text-secondary);
}

.quality-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.quality-options label {
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.95rem;
}

select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--card-background);
    color: var(--text-color);
    cursor: pointer;
    font-size: 0.9rem;
    transition: border-color 0.2s ease;
}

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

.compress-button {
    background: var(--success-color);
    color: white;
    border: none;
    padding: 0.875rem;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.compress-button:hover:not(:disabled) {
    background: var(--success-hover);
    transform: translateY(-1px);
}

.compress-button:disabled {
    background: #9ca3af;
    cursor: not-allowed;
}

.error-message {
    margin-top: 1.25rem;
    padding: 1rem;
    background: #fef2f2;
    border: 1px solid #fee2e2;
    border-radius: 6px;
    color: var(--error-color);
    font-size: 0.9rem;
}

.success-message {
    margin-top: 1.25rem;
    padding: 1.25rem;
    background: #f0fdf4;
    border: 1px solid #dcfce7;
    border-radius: 6px;
    color: var(--success-color);
}

.success-header {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    margin-bottom: 0.875rem;
    font-size: 0.95rem;
    font-weight: 500;
}

.success-icon {
    font-size: 1.25rem;
}

.compression-stats {
    margin: 0.875rem 0;
    padding: 0.875rem;
    background: var(--card-background);
    border-radius: 4px;
    font-size: 0.875rem;
}

.download-button {
    display: inline-block;
    background: var(--success-color);
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.25rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.download-button:hover {
    background: var(--success-hover);
    transform: translateY(-1px);
}

.tutorial-section {
    margin-top: 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.tutorial-section h2 {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 1.5rem;
    text-align: center;
}

.tutorial-steps {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.tutorial-step {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.step-number {
    background: var(--primary-color);
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h3 {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.step-content ul {
    list-style: none;
    margin-left: 0.5rem;
}

.step-content li {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.25rem;
}

.step-content li:before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
}

.tips-section {
    background: var(--background-color);
    padding: 1.25rem;
    border-radius: 8px;
    margin-top: 1.5rem;
}

.tips-section h3 {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.tips-section ul {
    list-style: none;
}

.tips-section li {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    position: relative;
    padding-left: 1.25rem;
}

.tips-section li:before {
    content: "💡";
    position: absolute;
    left: 0;
}

@media (max-width: 768px) {
    body {
        padding: 0.5rem;
    }

    .container {
        padding: 1rem;
        margin: 0;
        border-radius: 8px;
    }

    .logo-container {
        flex-direction: column;
        text-align: center;
    }

    .logo {
        width: 40px;
        height: 40px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .tutorial-step {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .step-content {
        text-align: left;
    }

    .step-content li {
        text-align: left;
    }

    .tips-section li {
        text-align: left;
    }
}