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

body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #00c853, #00bfa5);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
}

.container {
    width: 95%;
    max-width: 500px;
    padding: 20px;
}

h1 {
    text-align: center;
    margin-bottom: 10px;
    font-size: 40px;
}

.container > p {
    text-align: center;
    margin-bottom: 25px;
    opacity: 0.9;
}

.card {
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(10px);
    padding: 20px;
    border-radius: 20px;
    margin-bottom: 20px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.2);
}

.card h2 {
    margin-bottom: 15px;
}

input[type="text"],
input[type="file"] {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 10px;
    margin-bottom: 15px;
    font-size: 16px;
}

button {
    width: 100%;
    padding: 14px;
    border: none;
    border-radius: 12px;
    background: white;
    color: #00bfa5;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

button:hover {
    transform: scale(1.03);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.buttons {
    display: flex;
    gap: 10px;
}

#roomStatus,
#progressText {
    margin-top: 15px;
    text-align: center;
}

.progress-container {
    width: 100%;
    height: 20px;
    background: rgba(255,255,255,0.3);
    border-radius: 10px;
    overflow: hidden;
    margin-top: 15px;
}

.progress-bar {
    width: 0%;
    height: 100%;
    background: white;
    transition: width 0.3s;
}

#receivedFiles {
    margin-top: 10px;
}

.file-item {
    background: rgba(255,255,255,0.2);
    padding: 10px;
    border-radius: 10px;
    margin-top: 10px;
}