/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #1d1d1f;
    background-color: #ffffff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 22px;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 80px 0 100px;
    background-color: #fbfbfd;
}

.logo {
    width: 280px;
    max-width: 90%;
    height: auto;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 56px;
    font-weight: 600;
    line-height: 1.07;
    letter-spacing: -0.005em;
    margin-bottom: 20px;
    color: #1d1d1f;
}

.hero-description {
    font-size: 21px;
    line-height: 1.47;
    font-weight: 400;
    letter-spacing: 0.012em;
    color: #6e6e73;
    margin-bottom: 30px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.download-button {
    display: inline-block;
    background-color: #0071e3;
    color: #ffffff;
    padding: 14px 28px;
    border-radius: 980px;
    text-decoration: none;
    font-size: 17px;
    font-weight: 400;
    transition: background-color 0.2s ease;
}

.download-button:hover {
    background-color: #0077ed;
}

/* Problem Section */
.problem {
    padding: 80px 0;
    text-align: center;
    background-color: #ffffff;
}

.problem h2 {
    font-size: 40px;
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.003em;
    margin-bottom: 20px;
}

.problem p {
    font-size: 21px;
    line-height: 1.47;
    color: #6e6e73;
    max-width: 700px;
    margin: 0 auto;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: #fbfbfd;
}

.features h2 {
    font-size: 40px;
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.003em;
    text-align: center;
    margin-bottom: 60px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 50px;
    max-width: 980px;
    margin: 0 auto;
}

.feature {
    text-align: center;
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.feature h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 12px;
    color: #1d1d1f;
}

.feature p {
    font-size: 17px;
    line-height: 1.47;
    color: #6e6e73;
}

/* Privacy Section */
.privacy {
    padding: 80px 0;
    background-color: #ffffff;
}

.privacy h2 {
    font-size: 40px;
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.003em;
    text-align: center;
    margin-bottom: 60px;
}

.privacy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 40px;
    max-width: 980px;
    margin: 0 auto;
}

.privacy-item h3 {
    font-size: 21px;
    font-weight: 600;
    margin-bottom: 12px;
    color: #1d1d1f;
}

.privacy-item p {
    font-size: 17px;
    line-height: 1.47;
    color: #6e6e73;
}

/* Philosophy Section */
.philosophy {
    padding: 80px 0;
    background-color: #fbfbfd;
    text-align: center;
}

.philosophy h2 {
    font-size: 40px;
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.003em;
    margin-bottom: 30px;
}

.philosophy-text {
    font-size: 21px;
    line-height: 1.47;
    color: #6e6e73;
    max-width: 700px;
    margin: 0 auto 24px;
}

/* CTA Section */
.cta {
    padding: 80px 0;
    text-align: center;
    background-color: #ffffff;
}

.cta h2 {
    font-size: 40px;
    font-weight: 600;
    line-height: 1.1;
    margin-bottom: 30px;
}

.cta-note {
    margin-top: 20px;
    font-size: 14px;
    color: #6e6e73;
}

/* Footer */
footer {
    padding: 40px 0;
    text-align: center;
    background-color: #f5f5f7;
    border-top: 1px solid #d2d2d7;
}

footer p {
    font-size: 14px;
    color: #6e6e73;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 40px;
    }

    .hero-description {
        font-size: 19px;
    }

    .problem h2,
    .features h2,
    .privacy h2,
    .philosophy h2,
    .cta h2 {
        font-size: 32px;
    }

    .problem p,
    .philosophy-text {
        font-size: 19px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .privacy-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .hero {
        padding: 60px 0 80px;
    }

    .problem,
    .features,
    .privacy,
    .philosophy,
    .cta {
        padding: 60px 0;
    }

    .logo {
        width: 220px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 32px;
    }

    .hero-description {
        font-size: 17px;
    }

    .problem h2,
    .features h2,
    .privacy h2,
    .philosophy h2,
    .cta h2 {
        font-size: 28px;
    }

    .logo {
        width: 180px;
    }
}