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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #ffffff;
    color: #374151;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 30px 0;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.2);
}

header .container {
    text-align: center;
}

.logo h1 {
    font-size: 36px;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 6px;
    letter-spacing: 2px;
}

.logo span {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
}

main {
    padding: 45px 0;
}

section {
    margin-bottom: 20px;
    background: #ffffff;
    padding: 16px;
    border-radius: 10px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    border: 1px solid #f0f0f0;
}

section h2 {
    font-size: 18px;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid #e5e7eb;
    position: relative;
}

section h2::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 40px;
    height: 2px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.tool-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.tool-list li {
    padding: 5px 12px;
    background: linear-gradient(135deg, #f0f4ff 0%, #e8edff 100%);
    border-radius: 20px;
    transition: all 0.3s ease;
    border: 1px solid #e0e7ff;
}

.tool-list li:hover {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
    border-color: #3b82f6;
}

.tool-list a {
    text-decoration: none;
    color: #1e40af;
    font-weight: 500;
    font-size: 14px;
    transition: color 0.3s ease;
}

.tool-list li:hover a {
    color: #ffffff;
}

footer {
    background: #f8fafc;
    padding: 30px 0;
    text-align: center;
    border-top: 1px solid #e5e7eb;
    margin-top: 30px;
}

.friend-links {
    margin-bottom: 15px;
    font-size: 14px;
    color: #6b7280;
}

.friend-links span {
    margin-right: 10px;
}

.friend-links a {
    color: #667eea;
    text-decoration: none;
    margin: 0 8px;
    transition: color 0.3s ease;
}

.friend-links a:hover {
    color: #764ba2;
    text-decoration: underline;
}

footer p {
    font-size: 14px;
    color: #6b7280;
}

@media (max-width: 768px) {
    header {
        padding: 25px 0;
    }

    .logo h1 {
        font-size: 30px;
    }

    main {
        padding: 35px 0;
    }

    section {
        margin-bottom: 28px;
        padding: 20px;
    }

    section h2 {
        font-size: 18px;
    }

    .tool-list {
        gap: 8px;
    }

    .tool-list li {
        padding: 7px 14px;
    }

    .tool-list a {
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    header {
        padding: 20px 0;
    }

    .logo h1 {
        font-size: 26px;
    }

    .logo span {
        font-size: 13px;
    }

    main {
        padding: 25px 0;
    }

    section {
        margin-bottom: 22px;
        padding: 16px;
    }

    section h2 {
        font-size: 17px;
    }

    .tool-list {
        gap: 8px;
    }

    .tool-list li {
        padding: 6px 12px;
    }

    .tool-list a {
        font-size: 13px;
    }

    footer {
        padding: 22px 0;
    }

    footer p {
        font-size: 13px;
    }
}