*{box-sizing:border-box;font-family:-apple-system,BlinkMacSystemFont,"Noto Sans TC",sans-serif;margin:0;padding:0}
body{display:flex;justify-content:center;align-items:center;min-height:100vh;background:#f5f7fa;color:#333}
.container{width:400px;max-width:90vw;text-align:center}
.title{margin-bottom:24px;font-size:1.5rem;font-weight:600}
.drop-zone{border:3px dashed #aaa;border-radius:8px;padding:32px;cursor:pointer;transition:background .2s,border-color .2s}
.drop-zone.dragover{border-color:#0066ff;background:#e8f0fe}
.drop-zone.selected{border-color:#0066ff;background:#e6f3ff}
.drop-zone.selected .instruction{color:#0066ff;font-weight:500}
.upload-icon{color:#0066ff;margin-bottom:12px}
.instruction{display:block;color:#666}
.primary-btn{margin-top:24px;width:100%;padding:12px 0;border:none;border-radius:6px;background:#0066ff;color:#fff;font-size:1rem;cursor:pointer;box-shadow:0 2px 4px rgba(0,0,0,.15);transition:background .2s,box-shadow .2s}
.primary-btn:hover{background:#0057e6;box-shadow:0 4px 8px rgba(0,0,0,.2)}
.primary-btn:disabled{background:#b0c4ff;cursor:not-allowed;box-shadow:none}
.toast{position:fixed;bottom:32px;left:50%;transform:translateX(-50%) translateY(100%);background:#333;color:#fff;padding:12px 24px;border-radius:4px;opacity:0;transition:transform .3s,opacity .3s}
.toast.show{transform:translateX(-50%) translateY(0);opacity:1}
@media(max-width:480px){.drop-zone{padding:24px}.title{font-size:1.25rem}}