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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #10b981;
    --error-color: #ef4444;
    --text-color: #333;
    --text-light: #666;
    --border-color: #e0e0e0;
    --bg-light: #f8f9fa;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background: var(--bg-light);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
}

.logo-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

nav {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-link:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Upload Section */
.upload-section {
    padding: 3rem 0;
}

.upload-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    justify-content: center;
}

.tab-btn {
    padding: 0.75rem 2rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s;
}

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

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Upload Area */
.upload-area {
    background: white;
    border: 3px dashed var(--border-color);
    border-radius: 12px;
    padding: 3rem;
    text-align: center;
    transition: all 0.3s;
    cursor: pointer;
    margin-bottom: 2rem;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: #f8f9ff;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #f0f4ff;
    transform: scale(1.02);
}

.upload-content {
    pointer-events: none;
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1rem;
    color: var(--primary-color);
}

.upload-area h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.upload-area p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.hint {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
}

/* Buttons */
.btn {
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-block;
}

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

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-upload {
    width: 100%;
    background: var(--success-color);
    color: white;
    padding: 1rem;
    font-size: 1.1rem;
    margin-top: 1.5rem;
}

.btn-upload:hover:not(:disabled) {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.btn-upload:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.btn-copy {
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1.5rem;
    margin-left: 0.5rem;
}

.btn-copy:hover {
    background: #5568d3;
}

/* Selected Files */
.selected-files {
    margin-bottom: 2rem;
}

.file-item {
    background: white;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.file-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.file-preview {
    width: 60px;
    height: 60px;
    object-fit: cover;
    border-radius: 6px;
}

.file-details {
    flex: 1;
}

.file-name {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.file-size {
    font-size: 0.9rem;
    color: var(--text-light);
}

.remove-file {
    background: var(--error-color);
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-weight: 600;
}

.remove-file:hover {
    background: #dc2626;
}

/* Upload Options */
.upload-options {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.option-group {
    margin-bottom: 1.5rem;
}

.option-group:last-child {
    margin-bottom: 0;
}

.option-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.option-group select,
.option-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.option-group select:focus,
.option-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.option-group select:disabled {
    background: #f5f5f5;
    cursor: not-allowed;
}

/* URL Upload Form */
.url-upload-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
}

.url-upload-form label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.url-upload-form input[type="url"] {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    margin-bottom: 1.5rem;
    transition: border-color 0.3s;
}

.url-upload-form input[type="url"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    padding: 2.5rem;
    border-radius: 12px;
    max-width: 500px;
    width: 90%;
    text-align: center;
    position: relative;
    animation: slideDown 0.3s;
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    position: absolute;
    right: 1rem;
    top: 1rem;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-light);
    line-height: 1;
}

.close:hover {
    color: var(--text-color);
}

.success-icon {
    width: 80px;
    height: 80px;
    background: var(--success-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    margin: 0 auto 1.5rem;
    font-weight: bold;
}

.modal-content h2 {
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.result-url {
    display: flex;
    margin-bottom: 1rem;
}

.result-url input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px 0 0 8px;
    font-size: 1rem;
}

.info-text {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

/* Loading Overlay */
.loading-overlay {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.9);
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
    flex-direction: column;
}

.loading-overlay.active {
    display: flex;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

.loading-overlay p {
    color: var(--text-color);
    font-size: 1.1rem;
    font-weight: 600;
}

/* Footer */
footer {
    background: white;
    padding: 2rem 0;
    text-align: center;
    color: var(--text-light);
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .logo {
        font-size: 1.2rem;
    }

    .logo-img {
        height: 32px;
    }

    .logo-text {
        font-size: 1rem;
    }

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

    .subtitle {
        font-size: 1rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .file-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .result-url {
        flex-direction: column;
    }

    .result-url input {
        border-radius: 8px;
        margin-bottom: 0.5rem;
    }

    .btn-copy {
        margin-left: 0;
        width: 100%;
    }
}