/* --- 全般のリセットと共通変数 --- */
:root {
    --bg-color: #0a0a0c;
    --card-bg: #16161a;
    --text-color: #f5f5f7;
    --text-muted: #86868b;
    --accent-color: #0071e3;
    --gradient-start: #ff45fa;
    --gradient-end: #0071e3;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* --- ヘッダー --- */
header {
    background-color: rgba(10, 10, 12, 0.8);
    backdrop-filter: blur(20px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 100;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.logo {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

nav a {
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 20px;
    font-size: 0.9rem;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--text-color);
}

/* --- メインビジュアル (ヒーロー) --- */
.hero {
    padding-top: 140px;
    padding-bottom: 80px;
}

.hero-container {
    display: flex;
    align-items: center;
    gap: 40px;
}

.hero-text {
    flex: 1;
}

.badge {
    background-color: rgba(0, 113, 227, 0.15);
    color: #2997ff;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 20px;
}

.hero-text h1 {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-text p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 35px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #fff;
}

.btn-primary:hover {
    background-color: #0077ed;
    box-shadow: 0 0 20px rgba(0, 113, 227, 0.4);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.08);
    color: var(--text-color);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.15);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
}

.mockup-placeholder {
    width: 100%;
    max-width: 450px;
    height: 300px;
    background: linear-gradient(135deg, rgba(255, 69, 250, 0.1), rgba(0, 113, 227, 0.1));
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}

/* --- セクション共通 --- */
.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 50px;
    letter-spacing: -0.5px;
}

/* --- 機能特徴セクション --- */
.features {
    padding: 80px 0;
    background-color: rgba(255,255,255,0.01);
    border-top: 1px solid rgba(255, 255, 255, 0.02);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--card-bg);
    padding: 35px;
    border-radius: 14px;
    border: 1px solid rgba(255, 255, 255, 0.03);
    transition: transform 0.3s, border-color 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 113, 227, 0.3);
}

.feature-card .icon {
    font-size: 2rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* --- 使い方セクション --- */
.setup {
    padding: 80px 0 120px 0;
}

.setup-steps {
    display: flex;
    gap: 30px;
    position: relative;
}

.step {
    flex: 1;
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 14px;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.03);
}

.step-number {
    position: absolute;
    top: -20px;
    left: 30px;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

.step h3 {
    margin-top: 10px;
    margin-bottom: 12px;
    font-size: 1.15rem;
}

.step p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* --- ユースケースセクション --- */
.usecases {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.usecase-container {
    display: flex;
    flex-direction: column;
    gap: 80px; /* 各ケースの間の余白 */
}

.usecase-item {
    display: flex;
    align-items: center;
    gap: 50px;
}

/* 2番目の項目など、左右を反転させるためのクラス */
.usecase-item.reverse {
    flex-direction: row-reverse;
}

.usecase-image {
    flex: 1;
}

.usecase-img-placeholder {
    width: 100%;
    height: 280px;
    border-radius: 14px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    font-weight: 600;
    font-size: 1.1rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

/* 各ユースケースの雰囲気に合わせたグラデーション背景（仮） */
.youtube-ambient {
    background: linear-gradient(135deg, rgba(255, 0, 0, 0.15), rgba(0, 113, 227, 0.1));
}
.game-ambient {
    background: linear-gradient(135deg, rgba(0, 255, 135, 0.15), rgba(0, 113, 227, 0.1));
}
.work-ambient {
    background: linear-gradient(135deg, rgba(142, 68, 173, 0.15), rgba(0, 113, 227, 0.1));
}

.usecase-text {
    flex: 1;
}

.usecase-tag {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    border: 1px solid rgba(255, 255, 255, 0.15);
    padding: 4px 10px;
    border-radius: 4px;
    display: inline-block;
    margin-bottom: 15px;
}

.usecase-text h3 {
    font-size: 1.6rem;
    line-height: 1.3;
    margin-bottom: 15px;
    letter-spacing: -0.5px;
}

.usecase-text p {
    color: var(--text-muted);
    font-size: 0.98rem;
    text-align: justify;
}

/* スマホ対応の調整（既存の @media 内に追加するか、ここに単体で置く） */
@media (max-width: 768px) {
    .usecase-item, .usecase-item.reverse {
        flex-direction: column;
        gap: 25px;
        text-align: center;
    }
    .usecase-text h3 {
        font-size: 1.3rem;
    }
    .usecase-img-placeholder {
        height: 200px;
    }
}

/* --- フッター --- */
footer {
    background-color: #050507;
    padding: 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 20px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--text-color);
}

/* --- レスポンシブ (スマホ対応) --- */
@media (max-width: 768px) {
    .hero-container {
        flex-direction: column;
        text-align: center;
    }
    .hero-text h1 {
        font-size: 2.2rem;
    }
    .hero-buttons {
        justify-content: center;
    }
    .setup-steps {
        flex-direction: column;
        gap: 40px;
    }
    .step-number {
        top: -20px;
    }
    .footer-container {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
}