:root {
    --primary-color: #7C3AED;
    --primary-dark: #5B21B6;
    --primary-light: #A78BFA;
    --secondary-color: #06B6D4;
    --accent-color: #F59E0B;
    --text-dark: #1F1F2E;
    --text-gray: #6B7280;
    --bg-light: #F5F3FF;
    --bg-dark: #1F1F2E;
    --white: #FFFFFF;
    --border-color: #DDD6FE;
    --shadow: 0 2px 8px rgba(124,58,237,0.10);
    --shadow-hover: 0 8px 24px rgba(124,58,237,0.18);
    --gradient: linear-gradient(135deg, #7C3AED 0%, #06B6D4 100%);
    --gradient-hero: linear-gradient(135deg, #2D1B69 0%, #1F1F2E 60%, #0C4A6E 100%);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Yu Gothic', 'Hiragino Sans', sans-serif;
    color: var(--text-dark);
    line-height: 1.7;
    background-color: var(--white);
}

/* ヘッダーナビゲーション */
header {
    background: var(--bg-dark);
    box-shadow: 0 2px 16px rgba(124,58,237,0.3);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    font-size: 1.4rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 1.8rem;
    flex-wrap: wrap;
}

.nav-links a {
    color: #C4B5FD;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
    font-size: 0.95rem;
}

.nav-links a:hover {
    color: var(--white);
}

.nav-links a.active {
    color: var(--white);
}

.download-btn {
    background: var(--gradient) !important;
    color: var(--white) !important;
    padding: 0.55rem 1.4rem;
    border-radius: 8px;
    transition: opacity 0.2s, transform 0.2s !important;
    font-weight: 700 !important;
}

.download-btn:hover {
    opacity: 0.88;
    transform: translateY(-2px);
}

/* ハンバーガーメニュー */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 24px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 10;
}

.menu-toggle span {
    width: 100%;
    height: 3px;
    background: #C4B5FD;
    border-radius: 2px;
    transition: all 0.3s ease;
    transform-origin: center;
}

.menu-toggle.active span:nth-child(1) { transform: translateY(10px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-10px) rotate(-45deg); }

@media (max-width: 768px) {
    .menu-toggle { display: flex; }
    .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        gap: 0;
        background: var(--bg-dark);
        padding: 0.5rem 0;
    }
    .nav-links.active { display: flex; }
    .nav-links li a {
        display: block;
        padding: 0.8rem 1rem;
        border-top: 1px solid rgba(255,255,255,0.06);
    }
}

/* メインコンテンツ */
main {
    min-height: calc(100vh - 200px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.container.narrow {
    max-width: 860px;
}

/* ヒーローセクション */
.hero {
    background: var(--gradient-hero);
    color: var(--white);
    text-align: center;
    padding: 5rem 2rem 4rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 40%, rgba(124,58,237,0.35) 0%, transparent 50%),
                radial-gradient(circle at 70% 60%, rgba(6,182,212,0.25) 0%, transparent 50%);
    pointer-events: none;
}

.hero h1 {
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 900;
    margin-bottom: 1.2rem;
    line-height: 1.25;
    letter-spacing: -0.02em;
    position: relative;
}

.hero h1 .highlight {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: #C4B5FD;
    margin-bottom: 2rem;
    position: relative;
}

.hero-badges {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2.5rem;
    position: relative;
}

.badge {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    color: var(--white);
    padding: 0.4rem 1rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
    backdrop-filter: blur(8px);
}

.badge.highlight {
    background: rgba(124,58,237,0.4);
    border-color: var(--primary-light);
    color: #DDD6FE;
}

.cta-button {
    display: inline-block;
    background: var(--gradient);
    color: var(--white);
    padding: 1rem 2.5rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 800;
    font-size: 1.1rem;
    transition: opacity 0.2s, transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 20px rgba(124,58,237,0.4);
    position: relative;
    letter-spacing: 0.02em;
}

.cta-button:hover {
    opacity: 0.88;
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(124,58,237,0.5);
}

/* セクション */
section {
    margin-bottom: 3.5rem;
}

section h2 {
    font-size: 1.7rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
    letter-spacing: -0.01em;
}

section h2::after {
    content: '';
    display: block;
    width: 40px;
    height: 4px;
    background: var(--gradient);
    border-radius: 2px;
    margin-top: 0.5rem;
}

/* カードグリッド */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.8rem;
    box-shadow: var(--shadow);
    transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-3px);
}

.card-icon {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.6rem;
    color: var(--text-dark);
}

.card p {
    color: var(--text-gray);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* 比較カード */
.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 640px) {
    .comparison-grid { grid-template-columns: 1fr; }
}

.comparison-card {
    border-radius: 16px;
    padding: 1.8rem;
    border: 2px solid var(--border-color);
}

.comparison-card.premium {
    border-color: var(--primary-color);
    background: var(--bg-light);
    position: relative;
}

.comparison-card.premium::before {
    content: '✨ 超高速監視くん';
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--gradient);
    color: white;
    padding: 0.3rem 1.2rem;
    border-radius: 999px;
    font-size: 0.82rem;
    font-weight: 700;
    white-space: nowrap;
}

.comparison-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.comparison-card ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.comparison-card ul li {
    font-size: 0.93rem;
    color: var(--text-gray);
    padding: 0.3rem 0;
    border-bottom: 1px solid rgba(0,0,0,0.06);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.comparison-card.premium ul li {
    color: var(--text-dark);
    font-weight: 500;
}

/* フィーチャーリスト */
.feature-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.feature-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-dark);
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    font-size: 0.95rem;
}

.feature-list li::before {
    content: '✓';
    color: var(--primary-color);
    font-weight: 800;
    flex-shrink: 0;
    margin-top: 0.05rem;
}

.feature-list li:last-child {
    border-bottom: none;
}

.feature-list li ul {
    list-style: disc;
    padding-left: 1.2rem;
    margin-top: 0.3rem;
}

.feature-list li ul li::before {
    display: none;
}

/* ステップリスト */
.step-list {
    list-style: none;
    counter-reset: step-counter;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.step-list li {
    counter-increment: step-counter;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-light);
    border-radius: 10px;
    border-left: 4px solid var(--primary-color);
    font-size: 0.95rem;
}

.step-list li::before {
    content: counter(step-counter);
    background: var(--gradient);
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    flex-shrink: 0;
    font-size: 0.85rem;
}

/* 警告ボックス */
.warning-box {
    background: #FFFBEB;
    border: 1px solid #F59E0B;
    border-radius: 10px;
    padding: 1.2rem 1.5rem;
    margin-bottom: 1.5rem;
    color: #92400E;
    font-size: 0.93rem;
    line-height: 1.7;
}

.info-box {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.2rem 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
    font-size: 0.93rem;
    line-height: 1.7;
}

/* FAQアイテム */
.faq-item {
    border: 1px solid var(--border-color);
    border-radius: 10px;
    margin-bottom: 1rem;
    overflow: hidden;
    transition: box-shadow 0.2s;
}

.faq-item:hover {
    box-shadow: var(--shadow);
}

.faq-question {
    padding: 1.1rem 1.5rem;
    font-weight: 700;
    cursor: pointer;
    background: var(--bg-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.95rem;
}

.faq-question::after {
    content: '▼';
    color: var(--primary-color);
    font-size: 0.8rem;
    transition: transform 0.2s;
}

.faq-item.open .faq-question::after {
    transform: rotate(180deg);
}

.faq-answer {
    display: none;
    padding: 1.2rem 1.5rem;
    background: var(--white);
    color: var(--text-gray);
    font-size: 0.93rem;
    line-height: 1.8;
    border-top: 1px solid var(--border-color);
}

.faq-item.open .faq-answer {
    display: block;
}

/* 料金カード */
.pricing-card {
    border: 2px solid var(--primary-color);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(124,58,237,0.15);
    max-width: 560px;
    margin: 0 auto;
}

.pricing-header {
    background: var(--gradient);
    color: var(--white);
    padding: 1.8rem;
    text-align: center;
}

.pricing-header h3 {
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: 0.3rem;
}

.pricing-body {
    padding: 2rem;
}

.pricing-price {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.price-amount {
    font-size: 3.2rem;
    font-weight: 900;
    color: var(--primary-color);
    line-height: 1;
}

.price-period {
    font-size: 1rem;
    color: var(--text-gray);
}

/* バージョン履歴 */
.version-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.version-item {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 1.5rem;
}

.version-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.version-title {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.version-number {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--primary-color);
}

.version-badge {
    background: var(--gradient);
    color: white;
    padding: 0.2rem 0.7rem;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 700;
}

.version-date {
    color: var(--text-gray);
    font-size: 0.9rem;
}

.download-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient);
    color: white;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 0.9rem;
    transition: opacity 0.2s, transform 0.2s;
    margin-bottom: 1rem;
}

.download-link:hover {
    opacity: 0.88;
    transform: translateY(-2px);
}

.changelog {
    background: var(--white);
    border-radius: 10px;
    padding: 1.2rem;
    border: 1px solid var(--border-color);
}

.changelog h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.8rem;
    color: var(--text-dark);
}

.changelog ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.changelog ul li {
    font-size: 0.88rem;
    color: var(--text-gray);
    padding-left: 1rem;
    position: relative;
}

.changelog ul li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* スクリーンショット画像 */
.screenshot-img {
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(124,58,237,0.15);
    border: 2px solid var(--border-color);
}

/* フッター */
footer {
    background: var(--bg-dark);
    color: #C4B5FD;
    text-align: center;
    padding: 3rem 2rem;
    margin-top: 4rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    list-style: none;
    margin-bottom: 1.5rem;
}

.footer-links a {
    color: #A78BFA;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

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

.copyright {
    font-size: 0.85rem;
    color: #6D5FA6;
}

/* スペーシングユーティリティ */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

/* レスポンシブ */
@media (max-width: 640px) {
    .card-grid { grid-template-columns: 1fr; }
    .hero { padding: 3rem 1.5rem 2.5rem; }
    .container { padding: 2rem 1.2rem; }
    section h2 { font-size: 1.4rem; }
}