/* Reset & Base */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #1a56db;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary: #0f172a;
    --accent: #06b6d4;
    --text: #1e293b;
    --text-light: #64748b;
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gradient: linear-gradient(135deg, #1a56db 0%, #06b6d4 100%);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text);
    line-height: 1.7;
    background: var(--white);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    z-index: 1000;
}

.header-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    text-decoration: none;
    display: flex;
    flex-direction: column;
}

.logo-main {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-light);
}

.nav {
    display: flex;
    gap: 32px;
}

.nav-link {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(26, 86, 219, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(26, 86, 219, 0.4);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background: var(--gray-50);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-outline:hover {
    background: var(--white);
    color: var(--primary);
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.1rem;
}

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(180deg, var(--gray-50) 0%, var(--white) 100%);
    text-align: center;
}

.hero-title {
    font-size: 2.75rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 24px;
    color: var(--secondary);
}

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

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Problem Section */
.problem {
    padding: 100px 0;
    background: var(--white);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
    color: var(--secondary);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.problem-card {
    padding: 32px;
    background: var(--gray-50);
    border-radius: 16px;
    text-align: center;
}

.problem-icon {
    font-size: 3rem;
    margin-bottom: 16px;
}

.problem-card h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--secondary);
}

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

/* Solution Section */
.solution {
    padding: 100px 0;
    background: var(--gray-50);
}

.solution-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.solution-item {
    margin-bottom: 32px;
}

.solution-item:last-child {
    margin-bottom: 0;
}

.solution-item h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
    color: var(--secondary);
    position: relative;
    padding-left: 20px;
}

.solution-item h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
}

.solution-item p {
    color: var(--text-light);
    padding-left: 20px;
}

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

.image-placeholder {
    width: 100%;
    aspect-ratio: 4 / 3;
    background: var(--gray-200);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 0.9rem;
    border: 2px dashed var(--gray-200);
}

/* How to Use Section */
.how-to-use {
    padding: 100px 0;
    background: var(--white);
}

.steps {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 24px;
    margin-bottom: 60px;
}

.step {
    flex: 1;
    max-width: 280px;
    text-align: center;
    padding: 32px 24px;
    background: var(--gray-50);
    border-radius: 16px;
}

.step-number {
    width: 56px;
    height: 56px;
    background: var(--gradient);
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 700;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--secondary);
}

.step p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.step-arrow {
    color: var(--primary);
    font-size: 2rem;
    font-weight: 700;
    padding-top: 48px;
}

.steps-cta {
    text-align: center;
}

/* CTA Section */
.cta {
    padding: 100px 0;
    background: var(--secondary);
    text-align: center;
}

.cta-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 20px;
}

.cta-text {
    color: var(--gray-200);
    font-size: 1.1rem;
    margin-bottom: 40px;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Footer */
.footer {
    padding: 60px 0 30px;
    background: #0c1222;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 30px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 30px;
}

.footer-logo {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--white);
}

.footer-tagline {
    color: var(--text-light);
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: var(--gray-200);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
}

.footer-bottom p {
    color: var(--text-light);
    font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 900px) {
    .problem-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }

    .solution-content {
        grid-template-columns: 1fr;
    }

    .solution-image {
        order: -1;
    }

    .steps {
        flex-direction: column;
        align-items: center;
    }

    .step-arrow {
        transform: rotate(90deg);
        padding: 0;
    }
}

@media (max-width: 600px) {
    .header-container {
        height: 64px;
    }

    .nav {
        display: none;
    }

    .hero {
        padding: 120px 0 80px;
    }

    .hero-title {
        font-size: 1.85rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        gap: 16px;
    }
}