* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: #e0e0e0;
            background-color: #1a1a2e;
            overflow-x: hidden;
        }
        a {
            color: #00b4d8;
            text-decoration: none;
            transition: color 0.3s ease;
        }
        a:hover {
            color: #90e0ef;
            text-decoration: underline;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        .site-header {
            background: linear-gradient(135deg, #16213e 0%, #0f3460 100%);
            padding: 1rem 0;
            border-bottom: 3px solid #00b4d8;
            position: sticky;
            top: 0;
            z-index: 1000;
        }
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .my-logo {
            font-size: 2.2rem;
            font-weight: 800;
            color: #00b4d8;
            text-shadow: 0 2px 5px rgba(0, 180, 216, 0.5);
            font-family: 'Arial Black', sans-serif;
            letter-spacing: 1px;
        }
        .my-logo:hover {
            color: #90e0ef;
            text-decoration: none;
        }
        .main-nav ul {
            display: flex;
            list-style: none;
        }
        .main-nav li {
            margin-left: 1.8rem;
        }
        .main-nav a {
            color: #e0e0e0;
            font-weight: 600;
            font-size: 1.1rem;
            padding: 0.5rem 0.8rem;
            border-radius: 4px;
        }
        .main-nav a:hover {
            background-color: rgba(0, 180, 216, 0.2);
            text-decoration: none;
        }
        .hamburger {
            display: none;
            font-size: 1.8rem;
            background: none;
            border: none;
            color: #00b4d8;
            cursor: pointer;
        }
        .breadcrumb {
            padding: 1rem 0;
            background-color: #16213e;
            font-size: 0.9rem;
        }
        .breadcrumb a {
            color: #8d99ae;
        }
        .breadcrumb span {
            color: #e0e0e0;
        }
        .hero {
            padding: 3rem 0;
            background: radial-gradient(circle at top right, #0f3460, transparent 50%);
        }
        h1 {
            font-size: 3.2rem;
            color: #00b4d8;
            margin-bottom: 1.5rem;
            line-height: 1.2;
            text-shadow: 0 2px 4px rgba(0,0,0,0.5);
        }
        .lead {
            font-size: 1.3rem;
            color: #8d99ae;
            max-width: 900px;
            margin-bottom: 2rem;
        }
        .user-interaction {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
            padding: 2rem;
            background-color: rgba(22, 33, 62, 0.8);
            border-radius: 10px;
            border: 1px solid #00b4d8;
        }
        .interaction-box h3 {
            color: #00b4d8;
            margin-bottom: 1rem;
            font-size: 1.5rem;
        }
        .interaction-box form {
            display: flex;
            flex-direction: column;
        }
        .interaction-box input,
        .interaction-box textarea,
        .interaction-box select {
            padding: 0.8rem;
            margin-bottom: 1rem;
            border: 1px solid #0f3460;
            border-radius: 5px;
            background-color: #1a1a2e;
            color: #e0e0e0;
            font-size: 1rem;
        }
        .interaction-box button {
            padding: 0.8rem 1.5rem;
            background: linear-gradient(to right, #00b4d8, #0077b6);
            color: white;
            border: none;
            border-radius: 5px;
            font-weight: bold;
            cursor: pointer;
            transition: transform 0.2s ease;
        }
        .interaction-box button:hover {
            transform: translateY(-2px);
            background: linear-gradient(to right, #0077b6, #00b4d8);
        }
        .stars {
            display: flex;
            gap: 0.5rem;
            margin-bottom: 1rem;
        }
        .stars label {
            font-size: 1.8rem;
            color: #8d99ae;
            cursor: pointer;
        }
        .stars input {
            display: none;
        }
        .stars input:checked ~ label {
            color: gold;
        }
        .content-section {
            margin: 3rem 0;
            padding: 2rem;
            background-color: rgba(22, 33, 62, 0.6);
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.3);
        }
        h2 {
            font-size: 2.5rem;
            color: #00b4d8;
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid #0f3460;
        }
        h3 {
            font-size: 1.8rem;
            color: #90e0ef;
            margin: 1.8rem 0 1rem 0;
        }
        h4 {
            font-size: 1.4rem;
            color: #8d99ae;
            margin: 1.5rem 0 0.8rem 0;
        }
        p {
            margin-bottom: 1.2rem;
            font-size: 1.1rem;
            text-align: justify;
        }
        .highlight {
            background-color: rgba(0, 180, 216, 0.1);
            border-left: 4px solid #00b4d8;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-radius: 0 8px 8px 0;
        }
        .hero-img {
            width: 100%;
            max-width: 800px;
            margin: 2rem auto;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0,0,0,0.5);
        }
        .hero-img img {
            width: 100%;
            transition: transform 0.5s ease;
        }
        .hero-img img:hover {
            transform: scale(1.03);
        }
        .tier-list-table {
            width: 100%;
            border-collapse: collapse;
            margin: 2rem 0;
            background-color: #1a1a2e;
            border-radius: 10px;
            overflow: hidden;
        }
        .tier-list-table th,
        .tier-list-table td {
            padding: 1rem;
            text-align: left;
            border-bottom: 1px solid #0f3460;
        }
        .tier-list-table th {
            background-color: #0f3460;
            color: #00b4d8;
            font-size: 1.2rem;
        }
        .tier-list-table tr:hover {
            background-color: rgba(0, 180, 216, 0.1);
        }
        .tier-S { color: #ff6b6b; font-weight: bold; }
        .tier-A { color: #ffa726; font-weight: bold; }
        .tier-B { color: #66bb6a; font-weight: bold; }
        .tier-C { color: #42a5f5; font-weight: bold; }
        .tier-D { color: #ab47bc; font-weight: bold; }
        .related-links {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
            margin: 2rem 0;
            padding: 1.5rem;
            background-color: rgba(15, 52, 96, 0.5);
            border-radius: 10px;
        }
        .related-links a {
            display: inline-block;
            padding: 0.7rem 1.2rem;
            background-color: #16213e;
            border-radius: 5px;
            color: #8d99ae;
            border: 1px solid #0f3460;
            transition: all 0.3s ease;
        }
        .related-links a:hover {
            background-color: #00b4d8;
            color: #1a1a2e;
            border-color: #00b4d8;
            text-decoration: none;
        }
        .site-footer {
            background: #0f3460;
            padding: 3rem 0 1.5rem;
            margin-top: 4rem;
            border-top: 3px solid #00b4d8;
        }
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin-bottom: 2rem;
        }
        .footer-section h4 {
            color: #00b4d8;
            font-size: 1.3rem;
            margin-bottom: 1.2rem;
        }
        friend-link {
            display: block;
            margin-bottom: 0.5rem;
        }
        .copyright {
            text-align: center;
            padding-top: 1.5rem;
            border-top: 1px solid #16213e;
            color: #8d99ae;
            font-size: 0.9rem;
        }
        @media (max-width: 768px) {
            .header-content {
                flex-wrap: wrap;
            }
            .hamburger {
                display: block;
                order: 1;
            }
            .my-logo {
                order: 0;
                font-size: 1.8rem;
            }
            .main-nav {
                display: none;
                width: 100%;
                order: 2;
                margin-top: 1rem;
            }
            .main-nav.active {
                display: block;
            }
            .main-nav ul {
                flex-direction: column;
            }
            .main-nav li {
                margin: 0.5rem 0;
            }
            h1 {
                font-size: 2.5rem;
            }
            h2 {
                font-size: 2rem;
            }
            .user-interaction {
                grid-template-columns: 1fr;
            }
        }