* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
}

body {
    background-color: #f7f8fa;
    color: #333;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    height: 60px;
    display: flex;
    align-items: center;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}

body {
    padding-top: 60px; /* Prevent content from being hidden behind fixed header */
}

.header .container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 20px;
    font-weight: bold;
    color: #333;
}

.logo img {
    height: 32px;
    margin-right: 10px;
}

.nav a {
    margin-left: 20px;
    color: #666;
    transition: color 0.3s;
}

.nav a:hover {
    color: #007bff;
}

.btn-download-nav {
    padding: 8px 16px;
    background-color: #007bff;
    color: #fff !important;
    border-radius: 4px;
}

.btn-download-nav:hover {
    background-color: #0056b3;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%); /* Deep tech gradient */
    color: #fff;
    text-align: center;
    padding: 100px 20px;
    position: relative;
    overflow: hidden;
}

.hero h1 {
    font-size: 56px;
    margin-bottom: 10px;
    font-weight: 800;
    letter-spacing: 2px;
}

.main-tagline {
    font-size: 28px;
    font-weight: 300;
    margin-bottom: 20px;
    color: #00d2ff;
    text-transform: uppercase;
    letter-spacing: 5px;
}

.sub-desc {
    font-size: 16px;
    opacity: 0.8;
    margin-bottom: 50px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.download-area {
    margin-top: 30px;
}

.btn-download-main {
    display: inline-block;
    padding: 15px 50px;
    font-size: 20px;
    background: linear-gradient(to right, #00c6ff, #0072ff);
    color: #fff;
    border-radius: 50px;
    box-shadow: 0 4px 25px rgba(0, 198, 255, 0.4);
    font-weight: bold;
    transition: all 0.3s ease;
    border: none;
}

.btn-download-main:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0, 198, 255, 0.6);
    color: #fff;
}

.version-info {
    margin-top: 15px;
    font-size: 14px;
    opacity: 0.8;
}

.merged-features {
    margin-top: 80px;
    text-align: left; /* Optional: reset text alignment if needed, or keep center */
}

/* Categories */
.categories {
    background: #fff;
    padding: 20px 0;
    border-bottom: 1px solid #eee;
}

.cat-list {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
}

.cat-list li {
    padding: 8px 20px;
    cursor: pointer;
    border-radius: 20px;
    color: #666;
    transition: all 0.3s;
}

.cat-list li:hover {
    background-color: #f0f0f0;
    color: #333;
}

.cat-list li.active {
    background-color: #007bff;
    color: #fff;
}

/* Wallpaper Grid */
.wallpaper-grid {
    padding: 40px 0;
    background-color: #f7f8fa;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    transition: transform 0.3s;
    position: relative;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.card-img {
    height: 180px;
    background-color: #eee;
    position: relative;
}

.card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.3);
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 0.3s;
}

.card:hover .overlay {
    opacity: 1;
}

.overlay button {
    padding: 8px 20px;
    border: 1px solid #fff;
    background: transparent;
    color: #fff;
    border-radius: 20px;
    cursor: pointer;
}

.overlay button:hover {
    background: #fff;
    color: #333;
}

.more-btn-area {
    text-align: center;
    margin-top: 40px;
}

.btn-more {
    padding: 10px 30px;
    border: 1px solid #ddd;
    background: #fff;
    color: #666;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s;
}
.btn-more:hover {
    border-color: #007bff;
    color: #007bff;
}

/* Feature Items (merged into Hero) */
.feature-list {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 30px;
}

.feature-item {
    flex: 1;
    min-width: 250px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    transition: transform 0.3s, box-shadow 0.3s;
    text-align: left; /* Align text inside cards to left for better readability */
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 198, 255, 0.2);
    border-color: rgba(0, 198, 255, 0.3);
}

.feature-item h3 {
    margin-bottom: 15px;
    color: #00d2ff;
    font-size: 20px; /* Reduced slightly for hero context */
    letter-spacing: 1px;
    font-weight: 600;
}

.feature-item p {
    color: #dfdfdf;
    line-height: 1.6;
    font-size: 14px;
}

/* Footer */
.footer {
    background: #333;
    color: #999;
    padding: 40px 0;
    text-align: center;
    font-size: 14px;
}

.footer p {
    margin-bottom: 10px;
}