* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
}

body {
    background-color: #1a1a1a;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    flex-direction: column;
    background: linear-gradient(135deg, #2b2b2b, #1a1a1a);
}

.container {
    width: 400px;
    padding: 20px;
    background: #2c2c2c;
    border-radius: 15px;
    box-shadow: 0 0 15px rgba(0, 255, 100, 0.5);
    text-align: center;
    animation: fadeIn 0.8s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

h1 {
    font-size: 24px;
    font-weight: 600;
    text-transform: uppercase;
    background: linear-gradient(270deg, #4CAF50, #99ff99, #66ff99, #4CAF50);
    background-size: 300% 300%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: animasi-gradient 3s infinite linear;
}

@keyframes animasi-gradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.form-kirim {
    margin-top: 20px;
}

.form-kirim label {
    display: block;
    margin: 10px 0 5px;
    color: #fff;
    font-weight: 400;
}

.form-kirim input {
    width: 100%;
    padding: 10px;
    border: 2px solid #555;
    border-radius: 8px;
    background-color: #333;
    color: #fff;
    outline: none;
    transition: 0.3s;
}

.form-kirim input:focus {
    border-color: #4CAF50;
    box-shadow: 0 0 10px rgba(0, 255, 100, 0.6);
}

.form-kirim button {
    width: 100%;
    height: 40px;
    margin-top: 10px;
    border: none;
    border-radius: 8px;
    background: linear-gradient(135deg, #4CAF50, #2e8b57);
    color: #fff;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease-in-out;
    box-shadow: 0 4px 8px rgba(0, 255, 100, 0.3);
    position: relative;
    overflow: hidden;
}

.form-kirim button:hover {
    background: linear-gradient(135deg, #99ff99, #4CAF50);
    box-shadow: 0 4px 15px rgba(0, 255, 100, 0.6);
    transform: scale(1.05);
}

.form-kirim button:active {
    transform: scale(0.95);
}

#upload-button {
    margin-bottom: 10px;
}

.peringatan {
    color: red;
    font-size: 14px;
    margin-top: 10px;
    padding: 8px;
    border-radius: 5px;
    background-color: rgba(255, 0, 0, 0.2);
    display: none;
}

/* Footer */
.footer {
    margin-top: 15px;
    color: #ccc;
    font-size: 12px;
    text-align: center;
    padding-top: 10px;
    border-top: 1px solid #444;
}