:root {
    --bg-color: #0f172a;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --hover-bg: rgba(255, 255, 255, 0.05);
    --success: #10b981;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
}

/* Background Blobs for Atmosphere */
.background-blobs {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    filter: blur(80px);
    opacity: 0.6;
    animation: float 20s infinite alternate;
}

.blob-1 {
    width: 400px;
    height: 400px;
    background: #4f46e5;
    top: -100px;
    left: -100px;
}

.blob-2 {
    width: 500px;
    height: 500px;
    background: #7c3aed;
    bottom: -150px;
    right: -150px;
    animation-delay: -5s;
}

.blob-3 {
    width: 300px;
    height: 300px;
    background: #2563eb;
    top: 40%;
    left: 40%;
    animation-delay: -10s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(30px, 50px) scale(1.1); }
}

.container {
    width: 100%;
    max-width: 500px;
    padding: 20px;
    text-align: center;
    z-index: 10;
}

header {
    margin-bottom: 40px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 400;
}

/* Converter Card - Glassmorphism */
.converter-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.converter-card:hover {
    transform: translateY(-5px);
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--glass-border);
    border-radius: 16px;
    padding: 40px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: rgba(0, 0, 0, 0.2);
}

.drop-zone:hover, .drop-zone.drag-over {
    border-color: #818cf8;
    background: var(--hover-bg);
    transform: scale(1.02);
}

.icon-container {
    color: #818cf8;
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
}

.drop-zone h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.browse-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.highlight {
    color: #818cf8;
    text-decoration: underline;
    text-underline-offset: 4px;
}

/* Status Area */
.status-area {
    margin-top: 20px;
    padding: 15px;
    background: rgba(15, 23, 42, 0.5);
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--glass-border);
}

.status-area.hidden {
    display: none;
}

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

.file-name {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    max-width: 200px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.processing-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.success-message {
    display: flex;
    align-items: center;
    gap: 5px;
    color: var(--success);
    font-weight: 600;
    font-size: 0.9rem;
}

.success-message.hidden {
    display: none;
}

/* Spinner */
.spinner {
    animation: rotate 2s linear infinite;
    width: 20px;
    height: 20px;
}

.spinner .path {
    stroke: #818cf8;
    stroke-linecap: round;
    animation: dash 1.5s ease-in-out infinite;
}

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

@keyframes dash {
    0% { stroke-dasharray: 1, 150; stroke-dashoffset: 0; }
    50% { stroke-dasharray: 90, 150; stroke-dashoffset: -35; }
    100% { stroke-dasharray: 90, 150; stroke-dashoffset: -124; }
}

/* Download Button */
.download-btn {
    width: 100%;
    margin-top: 25px;
    padding: 14px;
    border: none;
    border-radius: 12px;
    background: var(--accent-gradient);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.download-btn:hover:not(:disabled) {
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.6);
    transform: translateY(-2px);
}

.download-btn:disabled {
    background: #334155;
    color: #64748b;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.btn-icon {
    width: 20px;
    height: 20px;
}

footer {
    margin-top: 50px;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.8rem;
    opacity: 0.6;
}