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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.nav-brand h2 {
    color: #6366f1;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: #374151;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover {
    color: #6366f1;
}

.premium-badge {
    background: linear-gradient(45deg, #f59e0b, #f97316);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Main Content */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: calc(100vh - 140px);
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 3rem;
    color: white;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* Tools Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.tool-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.tool-card.premium {
    border: 2px solid #f59e0b;
}

.premium-label {
    position: absolute;
    top: 12px;
    right: 12px;
    background: linear-gradient(45deg, #f59e0b, #f97316);
    color: white;
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.7rem;
    font-weight: 600;
}

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

.tool-card h3 {
    color: #1f2937;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.tool-card p {
    color: #6b7280;
    margin-bottom: 1.5rem;
}

.tool-btn {
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.2s;
    display: inline-block;
}

.tool-btn:hover {
    transform: scale(1.05);
}

/* Feature Highlights */
.feature-highlights {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.feature-highlights h3 {
    color: #1f2937;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.features-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 0.5rem;
}

.features-list li {
    color: #374151;
    font-weight: 500;
    padding: 0.5rem 0;
}

/* Tool Container */
.tool-container {
    display: flex;
    justify-content: center;
}

.upload-card {
    background: white;
    border-radius: 20px;
    padding: 2.5rem;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 600px;
}

/* Dropzone */
.dropzone {
    border: 3px dashed #d1d5db;
    border-radius: 16px;
    padding: 3rem 2rem;
    text-align: center;
    background: #f9fafb;
    transition: all 0.3s;
    cursor: pointer;
}

.dropzone:hover,
.dropzone.drag-over {
    border-color: #6366f1;
    background: #eff6ff;
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.drop-content h3 {
    color: #374151;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.drop-content p {
    color: #6b7280;
    margin-bottom: 1.5rem;
}

.select-btn {
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.select-btn:hover {
    transform: scale(1.05);
}

/* File List */
.file-list {
    margin: 2rem 0;
}

.file-list h4 {
    color: #374151;
    margin-bottom: 1rem;
    font-weight: 600;
}

.files {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #f3f4f6;
    padding: 1rem;
    border-radius: 12px;
    border-left: 4px solid #6366f1;
}

.file-info {
    color: #374151;
    font-weight: 500;
}

.file-info small {
    color: #6b7280;
    margin-left: 0.5rem;
}

.remove-btn {
    background: #ef4444;
    color: white;
    border: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s;
}

.remove-btn:hover {
    transform: scale(1.1);
}

/* Action Panel */
.action-panel {
    text-align: center;
    margin-top: 2rem;
}

.merge-btn {
    background: linear-gradient(45deg, #10b981, #059669);
    color: white;
    border: none;
    padding: 1rem 3rem;
    border-radius: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    min-width: 200px;
    position: relative;
}

.merge-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(16, 185, 129, 0.3);
}

.merge-btn:disabled {
    background: #9ca3af;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.loading {
    display: inline-block;
}

.hidden {
    display: none;
}

.status {
    margin-top: 1rem;
    font-weight: 500;
    padding: 0.75rem;
    border-radius: 8px;
}

.status.success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.status.error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    color: rgba(255, 255, 255, 0.8);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

    .hero h1 {
        font-size: 2rem;
    }

    .nav-container {
        padding: 0 1rem;
    }

    .nav-menu {
        gap: 1rem;
    }

    .upload-card {
        padding: 1.5rem;
    }

    .dropzone {
        padding: 2rem 1rem;
    }
}