/* RESET */
* { 
    margin:0; 
    padding:0; 
    box-sizing:border-box; 
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color:#1a1a1a;
    color:rgba(255, 255, 255, 0.54);
    min-height:100vh;
    line-height:1.7;
}

/* HEADER */
header {
    position:fixed;
    top:0; left:0; right:0;
    z-index:1000;
    background: rgba(26, 26, 26, 0);
    backdrop-filter: blur(20px);
    border-bottom:1px solid rgba(255, 255, 255, 0.121);
}

nav {
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:1rem 2rem;
    max-width:1200px;
    margin:0 auto;
}

.logo {
    font-size:1.5rem;
    font-weight:700;
    color:#ff6b9d;
    text-decoration:none;
}

.nav-center {
    position:absolute;
    left:50%;
    transform:translateX(-50%);
    color:#ccc;
    font-weight:500;
    font-size:1rem;
    max-width:400px;
    text-align:center;
}

.back-btn {
    color:#ff6b9d;
    text-decoration:none;
    padding:0.5rem 1rem;
    border:1px solid #ff6b9d;
    border-radius:8px;
    transition:all 0.3s ease;
}

.back-btn:hover {
    background:#ff6b9d;
    color:white;
}

.mobile-menu-btn { 
    display:none; 
    background:none; 
    border:none; 
    color:white; 
    font-size:1.5rem; 
    cursor:pointer; 
}

/* BACKGROUND */
.background {
    position:fixed;
    top:0; left:0; width:100%; height:100%;
    background: radial-gradient(circle at 20% 80%, rgba(120,119,198,0.3) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(255,119,198,0.15) 0%, transparent 50%);
    z-index:0;
}

/* SCROLL INDICATOR */
.scroll-indicator {
    position:fixed;
    top:0;
    left:0;
    width:100%;
    height:3px;
    background: rgba(255,107,157,0.2);
    z-index:1001;
}

.scroll-progress {
    height:100%;
    background: linear-gradient(90deg, #ff6b9d, #7877c6);
    width:0%;
    transition:width 0.1s ease;
}

/* MAIN CONTAINER */
.main-container {
    margin-top:80px;
    max-width:1200px;
    margin-left:auto;
    margin-right:auto;
    padding:2rem;
    display:flex;
    gap:2rem;
    position:relative;
    z-index:10;
}

/* SIDEBAR */
.sidebar {
    width:280px;
    flex-shrink:0;
}

/* META BOX */
.meta-box {
    background: rgba(255,107,157,0.08);
    border: 1px solid rgba(255,107,157,0.2);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.meta-box h3 {
    color:#ff6b9d;
    font-size:1rem;
    margin-bottom:1rem;
    text-align:center;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #ccc;
    margin-bottom: 0.5rem;
}

/* TABLE OF CONTENTS */
.toc {
    background: rgba(255,255,255,0.03);
    border:1px solid rgba(255,255,255,0.1);
    border-radius:12px;
    padding:1.5rem;
    position:sticky;
    top:100px;
}

.toc h3 {
    color:#ff6b9d;
    font-size:1.1rem;
    margin-bottom:1rem;
    text-align:center;
}

.toc ul {
    list-style:none;
}

.toc > ul > li {
    margin-bottom:0.8rem;
}

.toc a {
    color:#ccc;
    text-decoration:none;
    display:block;
    padding:0.3rem 0;
    border-left:2px solid transparent;
    padding-left:0.5rem;
    transition:all 0.3s ease;
    font-size:0.9rem;
}

.toc a:hover, .toc a.active {
    color:#ff6b9d;
    border-left-color:#ff6b9d;
}

.toc ul ul {
    margin-left:1rem;
    margin-top:0.5rem;
}

.toc ul ul a {
    font-size:0.85rem;
    opacity:0.8;
}

/* ARTICLE CONTENT */
.article {
    flex:1;
    background: rgba(255,255,255,0.02);
    border:1px solid rgba(255,255,255,0.1);
    border-radius:12px;
    padding:3rem;
    min-height:80vh;
}

.article-title {
    font-size:2.5rem;
    font-weight:700;
    color:#ff6b9d;
    margin-bottom:2rem;
    line-height:1.2;
}

/* TYPOGRAPHY */
h2 {
    color:#ff6b9d;
    font-size:1.8rem;
    margin:2.5rem 0 1rem 0;
    font-weight:600;
}

h3 {
    color:#ffb3d1;
    font-size:1.4rem;
    margin:2rem 0 1rem 0;
    font-weight:600;
}

p {
    margin-bottom:1.2rem;
    color:#ddd;
    font-size:1.05rem;
}

/* CODE BLOCKS */
.code-block {
    background: rgba(0,0,0,0.4);
    border:1px solid rgba(255,255,255,0.1);
    border-radius:8px;
    padding:1.5rem;
    margin:1.5rem 0;
    overflow-x:auto;
}

.code-header {
    color:#ff6b9d;
    font-size:0.85rem;
    font-weight:600;
    margin-bottom:1rem;
    text-transform:uppercase;
}

.code-block code {
    color:#fff;
    font-family: 'Monaco', 'Consolas', monospace;
    font-size:0.9rem;
    line-height:1.5;
    white-space:pre;
}

/* DEMO BOXES */
.demo-box {
    background: rgba(255,107,157,0.1);
    border:1px solid rgba(255,107,157,0.3);
    border-radius:12px;
    padding:2rem;
    margin:2rem 0;
    text-align:center;
}

.demo-element {
    width:80px;
    height:80px;
    background: linear-gradient(45deg, #ff6b9d, #7877c6);
    border-radius:12px;
    margin:0 auto 1rem;
    transition: all 0.3s ease;
    cursor:pointer;
}

.demo-element:hover {
    transform: scale(1.1) rotate(5deg);
}

.demo-element.bounce {
    animation: bounce 1s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* HIGHLIGHT BOXES */
.highlight-box {
    background: rgba(255,107,157,0.05);
    border-left:4px solid #ff6b9d;
    padding:1.5rem;
    margin:1.5rem 0;
    border-radius:0 8px 8px 0;
}

.highlight-box.tip {
    background: rgba(120,119,198,0.05);
    border-left-color:#7877c6;
}

.highlight-box h4 {
    color:#ff6b9d;
    margin-bottom:0.5rem;
    font-size:1.1rem;
}

.highlight-box.tip h4 {
    color:#7877c6;
}

.highlight-box ul {
    margin-left: 1.5rem;
    color: #ddd;
}

.highlight-box li {
    margin-bottom: 0.5rem;
}

/* FOOTER */
footer {
    text-align:center;
    padding:2rem;
    color:#666;
    position:relative;
    z-index:10;
}

/* RESPONSIVE */
@media(max-width:768px){
    .nav-center {
        display:none;
    }
    
    .mobile-menu-btn {
        display:block;
    }
    
    .main-container {
        flex-direction:column;
        padding:1rem;
        gap:1rem;
    }
    
    .sidebar {
        width:100%;
        order:2;
    }
    
    .article {
        order:1;
        padding:2rem 1.5rem;
    }
    
    .toc {
        position:relative;
        top:0;
    }
    
    .article-title {
        font-size:2rem;
    }
}