* {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      line-height: 1.5;
      background: #f7f7f7;
      color: #111;
    }

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

    /* NAVBAR */
    .top-nav {
      width: 100%;
      background: #ffffff;
      border-bottom: 1px solid #e3e3e3;
      padding: 10px 0;
      margin-bottom: 12px;
    }

    .nav-inner {
      width: 90%;
      max-width: 1180px;
      margin: 0 auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
    }

    .nav-logo {
      font-size: 1.2rem;
      font-weight: 700;
      color: #222;
      text-decoration: none;
    }

    .nav-links {
      display: flex;
      gap: 18px;
    }

    .nav-links a {
      color: #333;
      font-size: 0.95rem;
      text-decoration: none;
      padding: 6px 0;
      transition: color .15s ease;
    }

    .nav-links a:hover {
      color: #d91928;
    }

    @media (max-width: 768px) {
      .nav-inner {
        flex-direction: column;
        align-items: flex-start;
      }
      .nav-links {
        gap: 12px;
        flex-wrap: wrap;
      }
    }

    .page-shell {
      width: 90%;
      max-width: 1180px;
      margin: 0 auto;
      padding: 12px 10px 32px;
    }

    header {
      margin-bottom: 16px;
    }

    .brand-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      margin-bottom: 12px;
    }

    .brand-title {
      font-size: 1.4rem;
      font-weight: 600;
    }

    .brand-sub {
      font-size: 0.9rem;
      color: #555;
    }

    .banner-970x250 {
      width: 100%;
      max-width: 970px;
      height: 250px;
      min-height: 120px;
      margin: 0 auto;
      border-radius: 6px;
      background: #ddd;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.9rem;
      color: #555;
      text-align: center;
    }

    main {
      margin-top: 18px;
    }

    #intro {
      background: #fff;
      padding: 16px 14px;
      border-radius: 8px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.06);
      margin-bottom: 20px;
    }

    #intro h1 {
      font-size: 1.4rem;
      margin: 0 0 8px;
    }

    #intro p {
      margin: 6px 0;
      font-size: 0.96rem;
      color: #333;
    }

    #grid-section {
      margin-top: 6px;
    }

    #grid-section h2 {
      font-size: 1.1rem;
      margin: 0 0 10px;
    }

    .hint-text {
      font-size: 0.9rem;
      color: #666;
      margin-bottom: 8px;
    }

    .search-row {
      margin-bottom: 10px;
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      align-items: center;
    }

    #lesson-search {
      flex: 1;
      min-width: 200px;
      max-width: 380px;
      padding: 8px 10px;
      border-radius: 999px;
      border: 1px solid #cccccc;
      font-size: 0.9rem;
      outline: none;
      transition: border-color .15s ease, box-shadow .15s ease;
      background: #fff;
    }

    #lesson-search:focus {
      border-color: #d91928;
      box-shadow: 0 0 0 2px rgba(217,25,40,0.15);
    }

    .search-hint {
      font-size: 0.8rem;
      color: #777;
    }

    .load-banner {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 18px;
      border-radius: 999px;
      border: none;
      background: #d91928;
      font-size: 1rem;
      cursor: pointer;
      gap: 8px;
      color: #fff;
      font-weight: 600;
      animation: heartbeat 1.4s ease-in-out infinite;
      transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.2s ease;
      margin-bottom: 14px;
    }

    .load-banner:hover {
      background: #ff2839;
      transform: scale(1.06);
      box-shadow: 0 1px 8px rgba(255,45,72,0.6);
    }

    .load-banner:disabled {
      background: #999;
      animation: none;
      cursor: default;
      box-shadow: none;
      opacity: 0.7;
    }

    @keyframes heartbeat {
      0% { transform: scale(1); }
      15% { transform: scale(1.08); }
      30% { transform: scale(1); }
      45% { transform: scale(1.08); }
      70% { transform: scale(1); }
      100% { transform: scale(1); }
    }

    .lesson-grid {
	  display: grid;
	  grid-template-columns: repeat(auto-fill, minmax(140px, 180px)); /* kart max ~180px */
	  gap: 10px;
	  justify-content: flex-start; /* sola dizilsin */
	}


    .lesson-card {
      background: #fff;
      border-radius: 8px;
      padding: 8px;
      display: flex;
      flex-direction: column;
      gap: 6px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.06);
      transition: transform 0.08s ease, box-shadow 0.08s ease;
	  max-width: 180px;    
	  margin: 0 auto;     
    }

    .lesson-card:hover {
      transform: translateY(-1px);
      box-shadow: 0 2px 6px rgba(0,0,0,0.08);
    }

    .lesson-thumb-wrap {
      position: relative;
      width: 100%;
      aspect-ratio: 4 / 3;
      overflow: hidden;
      border-radius: 6px;
      background: #eee;
    }

    .lesson-thumb-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .lesson-label {
      font-size: 0.95rem;
      font-weight: 600;
      margin-top: 2px;
      word-break: break-word;
    }

    .lesson-meta {
      font-size: 0.78rem;
      color: #666;
    }

    .empty-note {
      font-size: 0.9rem;
      color: #777;
      margin-top: 6px;
    }

    footer {
      margin-top: 28px;
      font-size: 0.85rem;
      color: #777;
      text-align: center;
    }

    @media (max-width: 768px) {
      .page-shell {
        width: 100%;
        padding: 8px 8px 24px;
      }

      .banner-970x250 {
        height: 160px;
        min-height: 120px;
      }

      #intro {
        padding: 14px 12px;
      }
    }
	.search-row {
	display: none;  
	}