/* General Styling */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f6;
    color: #333;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    max-width: 700px;
    width: 100%;
    background: #ffffff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.07);
    text-align: center;
}

header h1 {
    font-size: 3rem;
    color: #2c3e50;
    margin: 0;
}

.tagline {
    font-size: 1.2rem;
    color: #7f8c8d;
    margin-top: 10px;
}

/* Intro Section */
.intro {
    text-align: left;
    margin: 40px 0;
}

.intro h2 {
    text-align: center;
    color: #34495e;
    margin-bottom: 20px;
}

.intro ul {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
    margin-top: 20px;
}

.intro ul li {
    background-color: #ecf0f1;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

/* Download Section */
.download-section h2 {
    margin-bottom: 20px;
}

.download-wrapper {
    position: relative;
    display: inline-block;
}

.download-btn {
    display: inline-block;
    background-color: #3498db;
    color: #fff;
    padding: 15px 30px;
    text-decoration: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: bold;
    transition: background-color 0.3s, transform 0.3s;
}

.download-btn:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
}

.qrcode-container {
    display: none; /* Hidden by default */
    position: absolute;
    bottom: 120%; /* Position above the button */
    left: 50%;
    transform: translateX(-50%);
    background: #fff;
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    z-index: 10;
}

.qrcode-container::after { /* Arrow pointing to the button */
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -10px;
    border-width: 10px;
    border-style: solid;
    border-color: #fff transparent transparent transparent;
}

/* WeChat Overlay */
.overlay {
    display: none; /* Hidden by default */
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    z-index: 100;
    text-align: right;
}

.overlay-content {
    padding: 20px;
}

.overlay-content .arrow {
    width: 60px;
    height: 60px;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="white"><path d="M4.5 19.5l6-6.001 6 6.001L21 15l-9-9L3 15l1.5 4.5z"/></svg>') no-repeat;
    background-size: contain;
    transform: rotate(45deg);
    margin-left: auto;
}

/* Footer */
footer {
    margin-top: 40px;
    color: #95a5a6;
    font-size: 0.9rem;
}