:root {
    --primary-color: #007bff;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #333;
    --secondary-text: #666;
    --gradient: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--gradient);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

#app {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.transfer-card {
    background: var(--card-bg);
    width: 360px;
    padding: 2.5rem;
    border-radius: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
}

h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.upload-area {
    border: 2px dashed #ddd;
    border-radius: 1rem;
    padding: 2rem;
    cursor: pointer;
    transition: border-color 0.2s;
    position: relative;
}

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

.upload-area input[type="file"] {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 2rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.file-list {
    text-align: left;
    max-height: 200px;
    overflow-y: auto;
    font-size: 0.9rem;
}

.file-item {
    padding: 0.5rem 0;
    border-bottom: 1px solid #eee;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.progress-container {
    background: #eee;
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    background: var(--primary-color);
    height: 100%;
    transition: width 0.1s;
}

.success-screen {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.link-box {
    background: #f0f0f0;
    padding: 0.75rem;
    border-radius: 0.5rem;
    font-family: monospace;
    font-size: 0.8rem;
    word-break: break-all;
    cursor: copy;
}

.copy-hint {
    font-size: 0.75rem;
    color: var(--secondary-text);
}