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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #FFFFFF;
    color: #17191b;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem 0;
    border-bottom: 2px solid #313c48;
    flex-wrap: wrap;
}

.logo-container {
    flex-shrink: 0;
}

.logo {
    filter: contrast(1.2);
}

.main-nav {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.main-nav a {
    text-decoration: none;
    color: #17191b;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.main-nav a:hover {
    background-color: #313c48;
    color: #FFFFFF;
}

.hero {
    text-align: center;
    padding: 4rem 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 20px;
    margin: 2rem 0;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, #17191b, #313c48);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.3rem;
    color: #313c48;
    font-weight: 500;
    margin-bottom: 2rem;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.hero-features span {
    background: #17191b;
    color: #FFFFFF;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.links-section, .validator-section, .content-section {
    margin: 3rem 0;
    padding: 2.5rem;
    background: #f8f9fa;
    border-radius: 15px;
    border: 1px solid #e9ecef;
}

.links-section h2, .validator-section h2, .content-section h2 {
    margin-bottom: 1.5rem;
    color: #17191b;
    font-size: 1.8rem;
    border-bottom: 2px solid #313c48;
    padding-bottom: 0.5rem;
}

.section-description {
    color: #313c48;
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.7;
}

.link-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    margin: 0.5rem 0;
    background: #FFFFFF;
    border: 1px solid #dee2e6;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.link-item:hover {
    border-color: #313c48;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(49, 60, 72, 0.1);
}

.link-text {
    word-break: break-all;
    font-family: monospace;
    color: #17191b;
    font-size: 0.9rem;
}

.copy-btn {
    background: #17191b;
    color: #FFFFFF;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.3s ease;
    margin-left: 1rem;
    flex-shrink: 0;
    font-size: 0.9rem;
}

.copy-btn:hover {
    background: #313c48;
}

.validator-container {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

#linkInput {
    flex: 1;
    min-width: 300px;
    padding: 0.75rem;
    border: 2px solid #dee2e6;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

#linkInput:focus {
    outline: none;
    border-color: #313c48;
}

.validator-container button {
    background: #17191b;
    color: #FFFFFF;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.3s ease;
}

.validator-container button:hover {
    background: #313c48;
}

#validationResult {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 8px;
    font-weight: 600;
    width: 100%;
}

.validation-valid {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.validation-invalid {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.content-block h3, .feature-item h3, .security-item h3, .guide-category h3 {
    color: #17191b;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    border-left: 4px solid #313c48;
    padding-left: 1rem;
}

.content-block p, .feature-item p, .security-item p, .guide-category p {
    color: #313c48;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.features-detail, .security-grid, .guides-container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.feature-item, .security-item, .guide-category {
    background: #FFFFFF;
    padding: 2rem;
    border-radius: 10px;
    border: 1px solid #e9ecef;
    transition: all 0.3s ease;
}

.feature-item:hover, .security-item:hover, .guide-category:hover {
    border-color: #313c48;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(49, 60, 72, 0.1);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 3rem 0;
}

.info-card {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid #e9ecef;
    transition: all 0.3s ease;
    text-align: center;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(49, 60, 72, 0.15);
    border-color: #313c48;
}

.info-card h3 {
    color: #17191b;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.info-card p {
    color: #313c48;
    line-height: 1.5;
}

.support-content p {
    color: #313c48;
    line-height: 1.7;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
    border-top: 2px solid #313c48;
    color: #313c48;
}

.footer-content p {
    margin-bottom: 0.5rem;
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .main-nav {
        justify-content: center;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-features {
        gap: 1rem;
    }
    
    .hero-features span {
        font-size: 0.8rem;
    }
    
    .validator-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    #linkInput {
        min-width: auto;
    }
    
    .content-grid {
        grid-template-columns: 1fr;
    }
    
    .links-section, .validator-section, .content-section {
        padding: 1.5rem;
    }
}