* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f5f5f5;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

/* PC Adaptation Container */
.container {
    width: 100%;
    max-width: 450px;
    background-color: #fff;
    position: relative;
    /* Add bottom padding to ensure bottom text isn't flush with edge if page is short */
    padding-bottom: 20px;
}

img {
    width: 100%;
    display: block;
}

/* Sticky Header */
.sticky-header {
    position: fixed;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 450px;
    z-index: 1000;
}

.sticky-bg {
    width: 100%;
    height: auto;
}

.sticky-btns {
    position: absolute;
    top: 50%;
    right: 5px; /* Increased right spacing */
    transform: translateY(-50%);
    display: flex;
    gap: 12px; /* Increased gap between header buttons */
    height: 55%; /* Slightly adjusted height ratio */
    padding: 5px; /* Add some padding area */
}

.sticky-btns a {
    display: block;
    height: 100%;
    transition: opacity 0.2s; /* Add hover effect */
}

.sticky-btns a:active {
    opacity: 0.8;
}

.sticky-btns img {
    height: 100%;
    width: auto;
}

/* Main Content Sections */
.section {
    width: 100%;
    position: relative;
}

/* Add some vertical rhythm if needed, though images are usually seamless. 
   User asked for margins/padding. */
.phone-section {
    margin-top: 15px; /* Fix potential sub-pixel rendering gaps between images */
    margin-bottom: 15px; /* Space before buttons */
    display: flex;
    justify-content: center;
    padding: 0 10px;
}

.phone-section img {
    width: auto;
    max-width: 100%;
}

/* Main Buttons Section */
.buttons-section {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 25px; /* Increased gap */
    padding: 0 20px 20px 20px; /* Increased vertical and horizontal padding */
}

.buttons-section a {
    display: block;
    width: 45%; /* Slightly wider buttons */
    max-width: 220px;
    transition: transform 0.1s;
}

.buttons-section a:active {
    transform: scale(0.98);
}

.buttons-section img {
    width: 100%;
    height: auto;
    /* Add shadow or border radius if images don't have them? 
       Usually images already contain the design. 
       Let's stick to layout spacing. */
}

/* Bottom Section */
.bottom-section {
    padding: 0 20px; /* Add side padding for text image if it's text */
    margin-top: 10px;
    margin-bottom: 30px; /* Bottom spacing */
}