/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: #f0f2f5;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.5;
}

/* Container */
.container {
    max-width: 600px; /* Mobile-first optimization */
    margin: 0 auto;
    /* background-color: #fff; Removed to allow body background to show */
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0,0,0,0.05);
}

/* Images */
.image-block {
    width: 100%;
    font-size: 0; /* Remove gap between images */
}

.img-fluid {
    width: 100%;
    height: auto;
    display: block;
}

/* Lazy Loading Transition */
img.lazy {
    opacity: 0;
    transition: opacity 0.3s ease-in;
}

img:not(.lazy) {
    opacity: 1;
}

/* Utilities */
.hidden { display: none; }