:root {
    --primary-color: #4a90e2;
    --secondary-color: #f5f5f5;
    --text-color: #333;
    --border-color: #ddd;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--secondary-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    color: var(--text-color);
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 500px;
    text-align: center;
}

header {
    margin-bottom: 2rem;
}

h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

p {
    color: #666;
    font-size: 0.9rem;
}

.upload-section {
    margin-bottom: 1rem;
}

.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 3rem 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--primary-color);
    background-color: #f0f8ff;
}

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

.hidden {
    display: none !important;
}

.btn-primary,
.btn-secondary {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    margin: 0.5rem;
    transition: transform 0.1s;
}

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

.btn-secondary {
    background-color: #e0e0e0;
    color: var(--text-color);
}

.btn-primary:active {
    transform: scale(0.98);
}

#file-info {
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

#filename {
    font-weight: bold;
    color: var(--primary-color);
}

.card {
    padding: 1rem;
}

#qr-image {
    width: 200px;
    height: 200px;
    margin: 1rem 0;
}

.link-container {
    display: flex;
    gap: 0.5rem;
    margin: 1rem 0;
}

#file-link {
    flex: 1;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: #f9f9f9;
}

#copy-btn {
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.btn-text {
    background: none;
    border: none;
    color: var(--primary-color);
    text-decoration: underline;
    cursor: pointer;
    margin-top: 1rem;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 1rem auto;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}