/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: url('https://images.gptkong.com/article/b/967_0.png') no-repeat center center fixed;
    background-size: cover;
    position: relative;
    overflow-x: hidden;
}
header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 0, 0, 0.8);
    color: #fff;
    padding: 20px 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
}
header nav {
    width: 90%;
    margin: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header nav a {
    color: #fff;
    text-decoration: none;
    margin: 0 15px;
    font-size: 16px;
    transition: color 0.3s ease;
}
header nav a:hover {
    color: #ffd700;
}
section {
    padding: 100px 20px 60px 20px;
    max-width: 1200px;
    margin: auto;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    margin-top: 80px;
}
section h2, section h3 {
    color: #b22222;
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}
section h2::after, section h3::after {
    content: '';
    width: 50px;
    height: 3px;
    background: #ffd700;
    position: absolute;
    left: 0;
    bottom: -10px;
    border-radius: 2px;
}
section p {
    margin-bottom: 20px;
    font-size: 17px;
    color: #555;
}
section img {
    display: block;
    max-width: 900px;
    width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    margin: 20px auto;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
section img:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}
.article-navigation {
    position: fixed;
    top: 80px;
    left: 20px;
    background: rgba(255, 255, 255, 0.9);
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    max-height: 80vh;
    overflow-y: auto;
}
.article-navigation a {
    display: block;
    color: #b22222;
    text-decoration: none;
    margin-bottom: 10px;
    font-size: 16px;
    transition: color 0.3s ease;
}
.article-navigation a:hover {
    color: #ffd700;
}
@media (max-width: 768px) {
    .article-navigation {
        position: static;
        max-height: none;
        width: 100%;
        margin-bottom: 20px;
    }
    header nav {
        flex-direction: column;
    }
    header nav a {
        margin: 10px 0;
    }
    section {
        padding: 80px 15px 40px 15px;
    }
}
@media (max-width: 480px) {
    section h2, section h3 {
        font-size: 18px;
    }
    section p {
        font-size: 15px;
    }
}
@keyframes fall {
    0% { transform: translateY(-10px) rotate(0deg); opacity: 1; }
    100% { transform: translateY(100vh) rotate(360deg); opacity: 0; }
}
.flower-petal {
    position: fixed;
    top: -50px;
    width: 30px;
    height: 30px;
    background: url('https://images.gptkong.com/article/b/967_3.png') no-repeat center center / cover;
    opacity: 0.8;
    animation: fall linear infinite;
}
.flower-petal:nth-child(1) {
    left: 10%;
    animation-duration: 10s;
    animation-delay: 0s;
}
.flower-petal:nth-child(2) {
    left: 30%;
    animation-duration: 12s;
    animation-delay: 2s;
}
.flower-petal:nth-child(3) {
    left: 50%;
    animation-duration: 14s;
    animation-delay: 4s;
}
.flower-petal:nth-child(4) {
    left: 70%;
    animation-duration: 11s;
    animation-delay: 1s;
}
.flower-petal:nth-child(5) {
    left: 90%;
    animation-duration: 13s;
    animation-delay: 3s;
}