ポップアップウィンドウ：フローティング｜Pop-up Window: Floating

<div class="container">
    <div id="popup-container">
        <button id="popup-btn" class="popup-btn">Floating Action</button>
    </div>
    <div id="popup" class="popup">
        <div class="popup-content">
            <p>Floating Action Popup</p>
            <p>A dynamic popup window with floating animation and action-oriented design.</p>
        </div>
    </div>
</div>

.container {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}
.container .popup-btn {
    cursor: pointer;
    border: none;
    padding: 12px 24px;
    border-radius: 16px;
    color: #333;
    background-color: #eee;
    font-weight: 600;
    box-shadow: 0 0 4px rgba(0, 0, 0, 0.3);
    display: block;
    margin: 0 auto;
    width: 180px;
}
.container .popup-btn:hover {
    opacity: 0.5;
}
.container .popup {
    position: fixed;
    bottom: -100%;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    max-width: 90%;
    max-height: 90%;
}
.container .popup.active {
    opacity: 1;
    visibility: visible;
    bottom: 20px;
    transform: translateX(-50%);
    animation: popupShowHide 3.4s ease forwards;
}
@keyframes popupShowHide {
    0% {
        opacity: 0;
        transform: translateX(-50%) translateY(100%);
    }
    20% {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
    80% {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
    100% {
        opacity: 0;
        transform: translateX(-50%) translateY(100%);
    }
}
.container .popup-content {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 30px;
    border-radius: 25px;
    text-align: center;
    position: relative;
    min-width: 300px;
    box-shadow: 0 20px 40px rgba(102, 126, 234, 0.3);
    border: 2px solid rgba(255,255,255,0.2);
    animation: floatingAction 3s ease-in-out infinite;
}
@keyframes floatingAction {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
}
.container .popup-content::before {
    content: '';
    position: absolute;
    top: -2px; left: -2px; right: -2px; bottom: -2px;
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4);
    border-radius: 27px;
    z-index: -1;
    animation: borderRotate 4s linear infinite;
}
@keyframes borderRotate {
    0% { filter: hue-rotate(0deg); }
    100% { filter: hue-rotate(360deg); }
}
.container .popup-content p:first-child {
    font-size: 24px;
    font-weight: bold;
    margin-bottom: 15px;
    color: white;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
    animation: textPulse 2s ease-in-out infinite;
}
@keyframes textPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}
.container .popup-content p:last-of-type {
    font-size: 16px;
    color: rgba(255,255,255,0.9);
    margin-bottom: 25px;
    line-height: 1.6;
}

document.addEventListener('DOMContentLoaded', function() {
    const popupBtn = document.getElementById('popup-btn');
    const popup = document.getElementById('popup');
    popupBtn.addEventListener('click', function() {
        popup.classList.add('active');
    });
    popup.addEventListener('animationend', function() {
        popup.classList.remove('active');
    });
});