/* ===== VARIABLES & RESET ===== */
:root {
    --red:        #e53b3b;
    --red-dark:   #b32424;
    --accent:     #ffce54;
    --bg-light:   #f9f9f9;
    --text-dark:  #333;
    --text-light: #fff;
    --muted:      rgba(0,0,0,.6);
    --radius:     12px;
    --shadow:     0 8px 24px rgba(0,0,0,.12);
    --transition: .25s ease;
    font-size:    16px;
  }
  *,
  *::before,
  *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: var(--bg-light);
    color: var(--text-dark);
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
  }
  a {
    text-decoration: none;
    color: var(--red-dark);
  }
  
  /* ===== FLEX & GRID HELPERS ===== */
  .flex { display: flex; }
  .wrap { flex-wrap: wrap; }
  .center { justify-content: center; }
  .center-v { align-items: center; }
  .between { justify-content: space-between; }
  
  /* ===== CONTAINER ===== */
  .container {
    width: 90%;
    max-width: 960px;
    margin: 0 auto;
  }
  
  /* ===== HEADER ===== */
  .site-header {
    background: linear-gradient(135deg, var(--red-dark), var(--red));
    color: var(--text-light);
  }
  .header-container {
    padding: 1rem 0;
  }
  .main-nav ul {
    list-style: none;
    gap: 1rem;
  }
  .main-nav ul li {
    display: inline-block;
  }
  .main-nav a {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    padding: .5rem .8rem;
    border-radius: var(--radius);
    transition: background var(--transition);
    color: var(--text-light);
  }
  .main-nav a:hover {
    background: rgba(255,255,255,.1);
  }
  .main-nav i {
    font-size: 1.2rem;
  }
  
  /* ===== ARTICLE SECTION ===== */
  .article-section {
    flex: 1;
    padding: 2rem 0;
  }
  .article-container {
    gap: 2rem;
  }
  /* main content */
  .article-content {
    flex: 2;
    min-width: 300px;
  }
  .article-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow);
  }
  .breadcrumb {
    font-size: .9rem;
    margin-bottom: 1rem;
  }
  .breadcrumb a {
    color: var(--red-dark);
  }
  .breadcrumb .sep {
    margin: 0 .5rem;
  }
  .article-title {
    font-size: 2rem;
    margin-bottom: .5rem;
    color: var(--red-dark);
  }
  .article-meta {
    font-size: .85rem;
    color: var(--muted);
    margin-bottom: 1.5rem;
  }
  .article-body {
    color: var(--text-dark);
  }
  .article-body img {
    max-width: 100%;
    margin: 1rem 0;
  }
  .article-body p {
    margin-bottom: 1rem;
  }
  .article-body h2,
  .article-body h3 {
    margin-top: 1.5rem;
    margin-bottom: .5rem;
    color: var(--red-dark);
  }
  .article-body ul,
  .article-body ol {
    padding-left: 1.2rem;
    margin-bottom: 1rem;
  }
  .article-body li {
    margin-bottom: .5rem;
  }
  
  /* ===== SIDEBAR ===== */
  .sidebar {
    flex: 1;
    min-width: 260px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }
  .banner-slot {
    background: #fff;
    border: 1px dashed var(--muted);
    border-radius: var(--radius);
    width: 300px;
    height: 250px;
    box-shadow: var(--shadow);
    overflow: hidden;
  }
  
  /* ===== FOOTER ===== */
  .site-footer {
    background: var(--red-dark);
    color: var(--text-light);
    text-align: center;
    padding: 1rem 0;
    font-size: .9rem;
  }
  .site-footer a {
    color: var(--accent);
  }
  .site-footer a:hover {
    text-decoration: underline;
  }
  
  /* ===== RESPONSIVE ===== */
  @media (max-width: 900px) {
    .article-container { flex-direction: column; }
    .sidebar { align-items: center; }
    .banner-slot { width: 100%; max-width: 300px; }
  }