:root {
    --bg-color: #0d0d11;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --primary: #D4566C;
    --primary-hover: #B8485D;
    --text-main: #ffffff;
    --text-secondary: #a1a1aa;
    --card-bg: rgba(255, 255, 255, 0.03);

    --sidebar-width: 280px;
    --radius-lg: 24px;
    --radius-md: 12px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 100px;
}

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    background-image:
        radial-gradient(circle at 10% 20%, rgba(212, 86, 108, 0.15) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(255, 101, 135, 0.12) 0%, transparent 20%);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

ul {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
}

.layout-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem 4rem;
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 3rem;
    position: relative;
}

.site-header {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.app-icon {
    width: 48px;
    height: 48px;
    background: rgba(212, 86, 108, 0.2);
    border: 1px solid rgba(212, 86, 108, 0.3);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #F5A0B3;
}

.brand-info h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #ffffff;
}

.platform-badge {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    font-weight: 500;
    margin-left: 0.5rem;
    display: inline-block;
    vertical-align: middle;
}

.lang-container {
    position: relative;
}

.lang-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-main);
    padding: 0.6rem 1rem;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s;
    backdrop-filter: blur(10px);
}

.lang-btn:hover {
    border-color: var(--primary);
    background: rgba(255, 255, 255, 0.1);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    width: 200px;
    background: rgba(13, 13, 17, 0.95);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(20px);
    overflow: hidden;
    opacity: 0;
    transform: translateY(-10px);
    pointer-events: none;
    transition: all 0.2s ease;
    z-index: 50;
    max-height: 300px;
    overflow-y: auto;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.lang-dropdown.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.lang-option {
    padding: 0.75rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: background 0.2s;
    cursor: pointer;
    color: var(--text-secondary);
}

.lang-option:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
}

.sidebar-sticky {
    position: sticky;
    top: 2rem;
    align-self: start;
    z-index: 40;
}

.contents-box {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    backdrop-filter: blur(20px);
    transition: all 0.3s ease;
}

.app-icon {
    padding: 0;
    background: transparent;
    border: none;
}

.app-icon img {
    width: 48px;
    height: 48px;
    border-radius: 16px;
    object-fit: cover;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.contents-header {
    padding: 1.25rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.contents-header h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-main);
}

.contents-toggle-icon {
    display: none;
}

.contents-list {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 0;
}

.contents-box.open .contents-list {
    max-height: 2000px;
    opacity: 1;
    padding: 0.5rem 0 1.5rem;
}

.contents-box.open .contents-toggle-icon {
    transform: rotate(180deg);
}

.toc-link {
    display: block;
    padding: 0.6rem 1.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: all 0.2s;
    border-left: 2px solid transparent;
}

.toc-link:hover {
    color: var(--text-main);
    background: rgba(255, 255, 255, 0.03);
}

.toc-link.active {
    color: var(--primary);
    border-left-color: var(--primary);
    background: rgba(212, 86, 108, 0.1);
    font-weight: 600;
}

.main-content {
    min-width: 0;
}

.hero-text {
    margin-bottom: 3rem;
}

.hero-text h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

.hero-sub {
    color: var(--text-secondary);
    font-size: 1rem;
}

.policy-section {
    margin-bottom: 3rem;
    scroll-margin-top: 100px;
    animation: fadeIn 0.6s ease-out;
}

.policy-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.policy-section p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1rem;
    line-height: 1.7;
}

.info-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1.5rem;
    margin-top: 1.5rem;
}

.info-card h4 {
    font-size: 1.1rem;
    color: #F5A0B3;
    margin-bottom: 0.5rem;
}

.footer-note {
    margin-top: 5rem;
    padding-top: 2rem;
    border-top: 1px solid var(--glass-border);
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-align: center;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: rgba(13, 13, 17, 0.8);
    border: 1px solid var(--glass-border);
    color: var(--primary);
    padding: 0.75rem 1.25rem;
    border-radius: 50px;
    font-weight: 600;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
    transition: all 0.3s;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    z-index: 40;
    backdrop-filter: blur(10px);
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

@media (max-width: 900px) {
    .layout-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}