:root {
  --primary-color: #d32f2f;
  --primary-hover: #b71c1c;
  --secondary-color: #343a40;
  --bg-color: #f8f9fa;
  --text-color: #212529;
  --text-muted: #6c757d;
  --white: #ffffff;
  --border-radius: clamp(8px, 2vw, 16px);
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 16px 32px rgba(0, 0, 0, 0.16);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --font-size-sm: clamp(0.875rem, 2vw, 1rem);
  --font-size-base: clamp(1rem, 2.5vw, 1.125rem);
  --font-size-lg: clamp(1.25rem, 3vw, 1.5rem);
  --font-size-xl: clamp(1.5rem, 4vw, 2rem);
  --font-size-2xl: clamp(1.875rem, 5vw, 2.5rem);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
    font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    margin: 0;
    background: linear-gradient(135deg, var(--bg-color) 0%, #e9ecef 100%);
    color: var(--text-color);
    line-height: 1.6;
    font-size: var(--font-size-base);
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: var(--spacing-md);
}

.container {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    max-width: min(90vw, 900px);
    width: 100%;
    display: grid;
    grid-template-rows: auto 1fr auto;
    min-height: 80vh;
    transition: var(--transition);
}

.container:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    transform: translateY(-2px);
}

.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #c62828 100%);
    color: var(--white);
    padding: var(--spacing-lg);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% { transform: translate(-50%, -50%) rotate(0deg); }
    50% { transform: translate(-50%, -50%) rotate(180deg); }
}

.header__title {
    margin: 0;
    font-size: var(--font-size-xl);
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    position: relative;
    z-index: 1;
}

.header__badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 20px;
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    font-weight: 500;
    position: relative;
    z-index: 1;
}

.main {
    padding: var(--spacing-xl);
    display: grid;
    gap: var(--spacing-xl);
}

.hero {
    display: grid;
    gap: var(--spacing-lg);
    align-items: center;
}

.hero__image-container {
    position: relative;
    overflow: hidden;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.hero__image {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    transition: var(--transition);
}

.hero__image:hover {
    transform: scale(1.02);
}

.hero__content {
    text-align: center;
}

.hero__title {
    color: var(--primary-color);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin: 0 0 var(--spacing-md) 0;
    line-height: 1.3;
}

.hero__description {
    margin-bottom: var(--spacing-lg);
}

.hero__text {
    font-size: var(--font-size-base);
    line-height: 1.8;
    color: var(--text-color);
    margin: 0 0 var(--spacing-md) 0;
}

.hero__cta {
    margin-top: var(--spacing-lg);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    text-decoration: none;
    border: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: var(--font-size-base);
    padding: var(--spacing-md) var(--spacing-xl);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn--primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, #b71c1c 100%);
    color: var(--white);
}

.btn--primary:hover {
    background: linear-gradient(135deg, var(--primary-hover) 0%, #8e0000 100%);
    box-shadow: 0 8px 25px rgba(211, 47, 47, 0.4);
    transform: translateY(-2px);
}

.btn__icon {
    font-size: 1.2em;
}

.btn__text {
    font-weight: 600;
}

.features {
    margin-top: var(--spacing-xl);
}

.features__title {
    text-align: center;
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-color);
    margin: 0 0 var(--spacing-lg) 0;
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.feature {
    text-align: center;
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature__icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.feature__title {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin: 0 0 var(--spacing-xs) 0;
    color: var(--text-color);
}

.feature__text {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin: 0;
    line-height: 1.6;
}

.footer {
    background: var(--secondary-color);
    color: var(--white);
    text-align: center;
    padding: var(--spacing-md);
}

.footer__text {
    margin: 0;
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.8);
}

@media (max-width: 768px) {
    body {
        padding: var(--spacing-sm);
    }

    .main {
        padding: var(--spacing-md);
        gap: var(--spacing-lg);
    }

    .hero {
        gap: var(--spacing-md);
    }

    .hero__image {
        aspect-ratio: 4 / 3;
    }

    .features__grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }

    .btn {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-sm);
    }
}

@media (min-width: 768px) {
    .hero {
        grid-template-columns: 1fr 1.2fr;
        text-align: left;
    }

    .hero__content {
        text-align: left;
    }

    .hero__cta {
        text-align: left;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #e9ecef;
        --text-muted: #adb5bd;
        --white: #2d3436;
        --secondary-color: #495057;
    }

    .feature {
        background: linear-gradient(135deg, #2d3436 0%, #495057 100%);
        border-color: rgba(255, 255, 255, 0.1);
    }
}