/* =========================================
   GLOBAL RESET
========================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* =========================================
   BODY & BASE STYLES
========================================= */
body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #5c3870, #3a2560);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 20px;
    color: #fff;
    animation: fadeInBody 0.8s ease-in-out;
}

/* Fade-in bij laden */
@keyframes fadeInBody {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* =========================================
   HEADER SECTION
========================================= */
.header-container {
    width: 100%;
    text-align: center;
    margin-bottom: 25px;
    animation: slideDown 1s ease;
}

.header-image {
    width: 80%;
    max-width: 480px;
    height: auto;
    transition: transform 0.4s ease;
}

.header-image:hover {
    transform: scale(1.03);
}

/* =========================================
   GLASS EFFECT CONTAINER
========================================= */
.container {
    width: 100%;
    max-width: 500px;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 25px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.25);
    animation: fadeInUp 1s ease;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.container:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

/* =========================================
   FORM STYLING
========================================= */
.form-group {
    margin-bottom: 15px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-size: 1.1em;
    font-weight: bold;
    color: #fff;
}

input[type="file"] {
    width: 100%;
    padding: 10px;
    font-size: 1em;
    margin-bottom: 20px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.4);
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
    transition: background-color 0.3s, border-color 0.3s;
}

input[type="file"]::file-selector-button {
    background: #4CAF50;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 8px 14px;
    margin-right: 10px;
    cursor: pointer;
    transition: background 0.3s;
}

input[type="file"]::file-selector-button:hover {
    background: #45a049;
}

input[type="submit"] {
    width: 100%;
    padding: 15px;
    font-size: 1.1em;
    border: none;
    border-radius: 8px;
    color: white;
    background: linear-gradient(135deg, #4CAF50, #3e8e41);
    cursor: pointer;
    transition: background 0.3s, transform 0.2s ease;
}

input[type="submit"]:hover {
    background: linear-gradient(135deg, #45a049, #367a3a);
    transform: scale(1.02);
}

/* =========================================
   BUTTON + IMAGE SECTION
========================================= */
.button-image-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    width: 100%;
    margin-top: 20px;
    gap: 10px;
}

.btn-gallery {
    display: inline-block;
    padding: 12px 20px;
    font-size: 1em;
    text-decoration: none;
    color: white;
    background: linear-gradient(135deg, #007BFF, #0056b3);
    border-radius: 8px;
    transition: background 0.3s, transform 0.2s ease;
    text-align: center;
    flex-grow: 1;
}

.btn-gallery:hover {
    background: linear-gradient(135deg, #339CFF, #004C99);
    transform: scale(1.05);
}

.serenium-img {
    max-width: 120px;
    height: auto;
    margin-left: auto;
    transition: transform 0.4s ease;
}

.serenium-img:hover {
    transform: rotate(2deg) scale(1.05);
}

/* =========================================
   ANIMATIONS
========================================= */
@keyframes slideDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* =========================================
   RESPONSIVE DESIGN (MOBILE-FRIENDLY)
========================================= */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .header-image {
        width: 100%;
    }

    .container {
        padding: 20px;
        backdrop-filter: blur(8px);
    }

    .button-image-container {
        flex-direction: column;
        align-items: center;
    }

    .btn-gallery {
        width: 100%;
        margin: 10px 0;
    }

    .serenium-img {
        margin: 10px 0 0 0;
    }
}

@media (max-width: 480px) {
    label, input, .btn-gallery, input[type="submit"] {
        font-size: 1em;
    }

    .container {
        padding: 15px;
    }
}