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

:root {
    --primary-color: #4a4a4a;
    --primary-dark: #2a2a2a;
    --secondary-color: #333333;
    --text-color: #333333;
    --text-light: #666666;
    --text-disabled: #999999;
    --border-color: #d0d0d0;
    --bg-light: #f5f5f5;
    --bg-white: #ffffff;
    --bg-disabled: #f9f9f9;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.12);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--bg-light);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.site-header {
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    padding: 0.5rem 0 0;
    box-shadow: var(--shadow);
}

.header-content {
    width: 80%;
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 2rem;
}

.header-main {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-bottom: 0.5rem;
    gap: 2rem;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-color);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--text-color);
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 600;
}

.primary-nav {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
}

.primary-nav-link {
    color: var(--text-light);
    text-decoration: none;
}

.primary-nav-link:hover {
    color: var(--text-color);
}

.secondary-nav {
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-light);
    padding: 0.35rem 0;
    font-size: 0.8rem;
}

.section-nav-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
    justify-content: center;
}

.section-nav-link {
    color: var(--text-light);
    text-decoration: none;
    padding: 0.1rem 0.25rem;
}

.section-nav-link:hover {
    color: var(--text-color);
}

.section-nav-separator {
    color: var(--border-color);
}

/* Main Content */
.container {
    width: 80%;
    max-width: 1600px;
    margin: 0 auto;
    padding: 1rem 2rem;
    flex: 1;
}

.hero-section {
    text-align: center;
    margin-bottom: 1.5rem;
    padding: 1rem 0;
}

.hero-section h1 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.description {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 1rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Subdomain Input */
.subdomain-input-section {
    max-width: 500px;
    margin: 0 auto;
}

.input-group {
    display: flex;
    align-items: center;
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 0.5rem;
    box-shadow: var(--shadow);
    transition: border-color 0.3s;
}

.input-group:focus-within {
    border-color: var(--text-color);
}

.subdomain-input {
    flex: 1;
    border: none;
    outline: none;
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    background: transparent;
}

.subdomain-suffix {
    color: var(--text-light);
    padding: 0 0.5rem;
    font-size: 0.85rem;
}

.submit-btn {
    background-color: var(--text-color);
    color: white;
    border: none;
    padding: 0.5rem 1.25rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-btn:hover {
    background-color: var(--primary-dark);
}

.submit-btn:active {
    transform: scale(0.98);
}

.error-message {
    color: #d32f2f;
    font-size: 0.9rem;
    margin-top: 0.5rem;
    text-align: left;
    min-height: 1.5rem;
}

.bookmark-hint {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-top: 0.25rem;
    min-height: 1.2rem;
}

/* Quick Links Section */
.quick-links-section {
    display: none;
}

.quick-links-section.active {
    display: block;
}

.section-header-row {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 0.75rem;
    margin-top: 2.25rem;
    margin-bottom: 0.75rem;
    padding-bottom: 0.35rem;
    border-bottom: 2px solid var(--text-color);
}

.section-header-row:first-of-type {
    margin-top: 1.5rem;
}

.section-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin: 0;
    padding: 0;
    border: none;
}

.section-title a {
    text-decoration: none;
    color: inherit;
}

.section-header-back-link {
    font-size: 0.75rem;
    color: var(--text-light);
    text-decoration: none;
    white-space: nowrap;
    padding-bottom: 0.35rem;
    margin-bottom: -2px;
    border-bottom: 2px solid var(--text-color);
}

.section-header-back-link:hover {
    color: var(--text-color);
}

.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.quick-link-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.6rem 0.6rem 0.55rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

.quick-link-card:hover:not(.disabled) {
    transform: translateY(-1px);
    box-shadow: var(--shadow-hover);
    background-color: #f2f1ff;
    border-color: #8e5cff;
}

.quick-link-card:hover:not(.disabled) .action-btn.open-link {
    background-color: #8e5cff;
    color: white;
    border-color: #8e5cff;
}

.quick-link-card.disabled {
    background: var(--bg-disabled);
    opacity: 0.6;
    cursor: not-allowed;
}

.quick-link-card.disabled .quick-link-name,
.quick-link-card.disabled .quick-link-description {
    color: var(--text-disabled);
}

.quick-link-card.disabled .quick-link-icon {
    color: var(--text-disabled);
}

.quick-link-header {
    display: flex;
    align-items: center;
    margin-bottom: 0.4rem;
}

.quick-link-icon {
    width: 24px;
    height: 24px;
    margin-right: 0.5rem;
    color: var(--text-color);
    flex-shrink: 0;
}

.quick-link-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-color);
    line-height: 1.3;
}

.quick-link-description {
    color: var(--text-light);
    font-size: 0.75rem;
    margin-bottom: 0.6rem;
    min-height: 1.6rem;
    line-height: 1.4;
}

.quick-link-actions {
    display: flex;
    gap: 0.5rem;
}

.action-btn {
    flex: 1;
    padding: 0.5rem 0.4rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--bg-white);
    color: var(--text-color);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
}

.action-btn:hover:not(:disabled) {
    background: var(--bg-light);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.action-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.action-btn.open-link {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.action-btn.open-link:hover:not(:disabled) {
    background: var(--primary-dark);
}

.action-btn.copied {
    background: #666666;
    color: white;
    border-color: #666666;
}

.action-btn svg {
    width: 14px;
    height: 14px;
}

/* Footer */
.site-footer {
    background-color: var(--bg-white);
    border-top: 1px solid var(--border-color);
    padding: 1rem 0;
    margin-top: 2rem;
    text-align: center;
}

.footer-content {
    width: 80%;
    max-width: 1600px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0.5rem 0;
}

.footer-note {
    font-size: 0.85rem;
    color: var(--text-light);
    font-style: italic;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background-color: var(--text-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease;
    z-index: 1000;
    opacity: 0;
    transform: translateY(20px);
}

.back-to-top.visible {
    display: flex;
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    background-color: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

/* Responsive */
@media (max-width: 1024px) {
    .container,
    .header-content,
    .footer-content {
        width: 90%;
    }
    
    .quick-links-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .container,
    .header-content,
    .footer-content {
        width: 95%;
        padding: 1rem;
    }
    
    .hero-section h1 {
        font-size: 1.5rem;
    }

    .quick-links-grid {
        grid-template-columns: 1fr;
    }

    .input-group {
        flex-wrap: wrap;
    }

    .subdomain-suffix {
        width: 100%;
        padding: 0.5rem 1rem;
        order: 3;
    }

    .submit-btn {
        width: 100%;
        margin-top: 0.5rem;
    }

    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 44px;
        height: 44px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1rem;
    }

    .hero-section {
        padding: 1rem 0;
    }

    .hero-section h1 {
        font-size: 1.75rem;
    }

    .description {
        font-size: 1rem;
    }
}