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

body {
    font-family: Arial, sans-serif;
    background: #ffffff;
    color: #0f172a;
    padding: 20px;
    text-align: center;
}

h1 {
    font-size: 30px;
    margin-bottom: 8px;
}

.subtext {
    color: #475569;
    font-size: 16px;
    margin-bottom: 25px;
}

/* CONTAINER */
.container {
    width: 95%;
    max-width: 800px;
    margin: 0 auto;
    background: #0f172a;
    padding: 35px;
    border-radius: 16px;
    color: #ffffff;
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 0 25px rgba(0,0,0,0.15);
}

/* DRAG & DROP BOX */
.upload-box {
    width: 100%;
    border: 3px dashed #38bdf8;
    padding: 55px 20px;
    border-radius: 14px;
    background: rgba(255,255,255,0.05);
    cursor: pointer;
    transition: 0.3s;
    color: #ffffff;
    font-size: 18px;
}

.upload-box.dragover {
    background: rgba(56,189,248,0.25);
    border-color: #0ea5e9;
}

.upload-box small {
    display: block;
    margin-top: 10px;
    opacity: 0.8;
    font-size: 14px;
}

#fileName {
    margin-top: 18px;
    font-size: 16px;
    color: #e2e8f0;
    word-wrap: break-word;
}

/* BUTTONS */
button, .download-btn {
    width: 100%;
    padding: 15px 0;
    background: #0ea5e9;
    color: #ffffff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 18px;
    margin-top: 30px;
    text-decoration: none;
}

button:hover, .download-btn:hover {
    background: #0284c7;
}

/* SPINNER */
.big-spinner {
    width: 70px;
    height: 70px;
    border: 6px solid rgba(255,255,255,0.2);
    border-top: 6px solid #0ea5e9;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

#loading {
    display: none;
    margin-top: 30px;
    font-size: 18px;
    color: #38bdf8;
}

#downloadSection {
    display: none;
    margin-top: 20px;
}

/* MOBILE */
@media (max-width: 480px) {
    h1 { font-size: 24px; }
    .container { padding: 22px; }
    .upload-box { padding: 35px 15px; font-size: 16px; }
    button { font-size: 16px; padding: 12px 0; }
}