:root {
    --color-black: #141414;
    --color-dark-brown: #403020;
    --color-mid-gray: #605850;
    --color-dark-purple: #802850;
    --color-dark-blue: #184480;
    --color-light-blue: #20B0E8;
    --color-dark-green: #108050;
    --color-light-green: #40C840;
    --color-yellow: #E8E040;
    --color-orange: #E89810;
    --color-red: #C82040;
    --color-copper: #A85038;
    --color-peach: #E0C0A0;
    --color-skin: #F8D0A8;
    --color-light-gray: #C0C8C8;
    --color-white: #F4F4F4;

    --bg-color: var(--color-black);
    --text-color: var(--color-white);
    --primary: var(--color-yellow);
    --secondary: var(--color-dark-brown);
    --accent: var(--color-orange);
    --glass-bg: rgba(96, 88, 80, 0.15);
    /* mid-gray with opacity */
    --glass-border: rgba(244, 244, 244, 0.08);
    /* white with low opacity */
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* Background Effects */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -2;
    overflow: hidden;
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(25px);
    z-index: -1;
    opacity: 0.85;
    background: radial-gradient(circle, var(--color-yellow) 30%, var(--color-orange) 65%, transparent 100%);
    box-shadow: inset 0 0 30px 15px var(--color-orange), 0 0 40px 10px var(--color-orange);
    animation: riseUp 25s infinite linear;
    bottom: -200px;
}

.orb-1 {
    width: 150px;
    height: 150px;
    left: 10%;
    animation-duration: 20s;
}

.orb-2 {
    width: 250px;
    height: 250px;
    left: 40%;
    animation-duration: 35s;
    animation-delay: -5s;
    opacity: 0.4;
}

.orb-3 {
    width: 100px;
    height: 100px;
    left: 70%;
    animation-duration: 15s;
    animation-delay: -12s;
}

.orb-4 {
    width: 200px;
    height: 200px;
    left: 85%;
    animation-duration: 28s;
    animation-delay: -18s;
    opacity: 0.5;
}

@keyframes riseUp {
    0% {
        transform: translateY(0) scale(0.8);
        opacity: 0;
    }

    20% {
        opacity: 0.6;
    }

    80% {
        opacity: 0.6;
    }

    100% {
        transform: translateY(-120vh) scale(1.2);
        opacity: 0;
    }
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 5%;
    background: rgba(20, 20, 20, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--glass-border);
    transition: all 0.3s ease;
}

header.scrolled {
    padding: 1rem 5%;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

.logo {
    font-size: 1.8rem;
    font-weight: 900;
    color: var(--color-white);
    letter-spacing: 2px;
    transition: color 0.3s ease;
}

.logo-link:hover .logo {
    color: var(--color-orange);
}

.header-nav {
    display: flex;
    align-items: center;
}

.btn-nav {
    display: inline-block;
    padding: 0.6rem 1.5rem;
    font-size: 0.9rem;
    background: transparent;
    color: var(--color-white);
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: all 0.3s ease;
    border: 1px solid var(--color-orange);
}

.btn-nav:hover {
    background: var(--color-orange);
    color: var(--color-white);
    box-shadow: 0 0 15px rgba(232, 152, 16, 0.4);
}

/* Main Content */
main {
    padding-top: 120px;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-bottom: 4rem;
}

.hero {
    text-align: center;
    padding: 8rem 2rem 5rem;
    max-width: 900px;
    animation: fadeInDown 1s ease-out;
}

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

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

.main-title {
    font-size: 4.5rem;
    font-weight: 900;
    margin-bottom: 1.5rem;
    color: var(--color-white);
    line-height: 1.2;
    letter-spacing: 2px;
    display: inline-block;
    text-align: left;
}

.accent-text {
    color: var(--accent);
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--color-light-gray);
    margin-bottom: 3rem;
    line-height: 1.8;
}

.btn-primary {
    display: inline-block;
    padding: 1.2rem 3rem;
    font-size: 1.1rem;
    background: linear-gradient(135deg, var(--color-orange), var(--color-copper));
    color: var(--color-white);
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: all 0.3s ease;
    border: 1px solid rgba(244, 244, 244, 0.1);
}

.btn-primary:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 10px 25px rgba(232, 152, 16, 0.5);
    border-color: rgba(244, 244, 244, 0.3);
}

/* Glass Panels */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 4rem;
    margin: 2rem 1rem;
    max-width: 1000px;
    width: calc(100% - 2rem);
    text-align: center;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.fade-in-section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in-section.visible {
    opacity: 1;
    transform: translateY(0);
}

.glass-panel h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    letter-spacing: 1px;
}

.about-text {
    font-size: 1.1rem;
    color: var(--color-light-gray);
    line-height: 2;
}

#about {
    position: relative;
    z-index: 10;
    background-color: var(--bg-color);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--color-mid-gray);
    border-top: 1px solid var(--glass-border);
    margin-top: auto;
    font-size: 0.9rem;
}

/* --- Manual Page Styles --- */
.manual-page {
    background-color: var(--color-black);
}

.logo-link {
    text-decoration: none;
}

.manual-container {
    display: flex;
    gap: 3rem;
    padding: 120px 5% 4rem;
    max-width: 1200px;
    margin: 0 auto;
    align-items: flex-start;
}

/* Sidebar / Table of Contents */
.sidebar {
    width: 250px;
    flex-shrink: 0;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 2rem 1.5rem;
    backdrop-filter: blur(10px);
}

.toc h3 {
    color: var(--color-white);
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 0.5rem;
}

.toc ul {
    list-style: none;
}

.toc li {
    margin-bottom: 1rem;
}

.toc a {
    color: var(--color-light-gray);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
    display: block;
}

.toc a:hover {
    color: var(--color-light-gray); /* ホバー時の色変化を無効化 */
}

.toc ol {
    padding-left: 1.5rem; /* 番号の表示スペース */
    list-style-type: decimal;
}

.toc ol li {
    margin-bottom: 1rem;
}

.toc ol li a {
    display: block;
}

/* Manual Content Area */
.content {
    flex: 1;
    min-width: 0;
}

.page-title {
    font-size: 2.8rem;
    font-weight: 900;
    color: var(--color-white);
    margin-bottom: 3rem;
    letter-spacing: 1px;
}

.manual-section {
    padding: 3rem;
    margin: 0 0 2rem 0;
    text-align: left;
    max-width: 100%;
    width: 100%;
    scroll-margin-top: 100px;
}

.manual-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid rgba(232, 152, 16, 0.3);
    padding-bottom: 0.8rem;
}

.manual-section p {
    color: var(--color-light-gray);
    font-size: 1.1rem;
    line-height: 1.9;
    margin-bottom: 1rem;
}

.manual-section strong {
    color: var(--color-white);
    background: rgba(232, 152, 16, 0.15);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
}

.manual-section ul,
.manual-section ol {
    margin: 1.5rem 0 1.5rem 1.5rem;
    color: var(--color-light-gray);
}

.manual-section li {
    margin-bottom: 0.8rem;
    line-height: 1.7;
}

.manual-section h3 {
    font-size: 1.4rem;
    color: var(--color-white);
    margin: 2rem 0 1rem;
}

/* FAQ specifics */
.faq-item {
    margin-bottom: 2rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 1.5rem;
    border-radius: 12px;
    border-left: 4px solid var(--color-orange);
}

.faq-item h3 {
    color: var(--color-yellow);
    font-size: 1.2rem;
    margin-bottom: 0.8rem;
}

.faq-item p {
    margin-bottom: 0;
}

.inline-link {
    color: var(--color-light-blue);
    text-decoration: none;
    font-weight: bold;
    border-bottom: 1px solid transparent;
    transition: all 0.3s ease;
}

.inline-link:hover {
    border-bottom-color: var(--color-light-blue);
    color: var(--color-white);
}

.invite-link {
    color: var(--color-light-blue);
    text-decoration: none;
    font-weight: bold;
    border-bottom: 1px solid transparent;
    transition: all 0.3s ease;
}

.invite-link:hover {
    border-bottom-color: var(--color-light-blue);
    color: #fff;
}

.manual-img-container {
    margin: 2rem 0;
    text-align: center;
}

.step-img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    border: 1px solid var(--glass-border);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.manual-page footer {
    width: 100%;
}

/* Media Queries */
@media (max-width: 900px) {
    .manual-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: static;
        margin-bottom: 2rem;
    }
}

@media (max-width: 768px) {
    .main-title {
        font-size: 3rem;
    }

    .hero {
        padding: 6rem 1rem 3rem;
    }

    .glass-panel {
        padding: 2rem 1.5rem;
    }
}