:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg-dark: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border: rgba(255, 255, 255, 0.1);
    --success: #10b981;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-image: 
        radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.15) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(16, 185, 129, 0.1) 0px, transparent 50%);
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 2rem;
}

.card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: 24px;
    padding: 3rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    text-align: center;
}

h1 {
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #818cf8, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

p {
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    line-height: 1.6;
}

.drop-zone {
    border: 2px dashed rgba(99, 102, 241, 0.3);
    border-radius: 20px;
    padding: 3rem 2rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: rgba(15, 23, 42, 0.3);
    position: relative;
    overflow: hidden;
}

.drop-zone:hover, .drop-zone.drag-over {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.05);
    transform: translateY(-2px);
}

.drop-zone i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    display: block;
}

.drop-zone-text {
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.drop-zone-hint {
    font-size: 0.875rem;
    color: var(--text-muted);
}

#file-input {
    display: none;
}

.file-list {
    margin-top: 2rem;
    text-align: left;
}

.file-item {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    animation: slideUp 0.4s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.file-info {
    display: flex;
    flex-direction: column;
}

.file-name {
    font-weight: 600;
    font-size: 0.95rem;
}

.file-size {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.btn-migrate {
    width: 100%;
    margin-top: 2.5rem;
    padding: 1.25rem;
    border-radius: 16px;
    border: none;
    background: var(--primary);
    color: white;
    font-weight: 700;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.btn-migrate:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 10px 15px -3px rgba(99, 102, 241, 0.3);
}

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

.progress-bar-container {
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    margin-top: 1rem;
    overflow: hidden;
    display: none;
}

.progress-bar {
    height: 100%;
    background: var(--success);
    width: 0%;
    transition: width 0.3s ease;
}