```css
body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #f4f6f9;
    color: #222;
}


/* HERO */

.hero {
    background-color: #232f3e;
    color: white;
    text-align: center;
    padding: 70px 20px;
}

.profile-photo {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid #ff9900;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 48px;
    margin: 0 0 12px;
}

.hero-title {
    font-size: 22px;
    font-weight: bold;
    margin: 0 0 10px;
}

.hero-subtitle {
    font-size: 16px;
    margin: 0 0 30px;
    opacity: 0.9;
}

.button {
    display: inline-block;
    background-color: #ff9900;
    color: #232f3e;
    padding: 12px 22px;
    text-decoration: none;
    font-weight: bold;
    border-radius: 6px;
    transition:
        background-color 0.2s ease,
        transform 0.2s ease;
}

.button:hover {
    background-color: #e88b00;
    transform: translateY(-2px);
}


/* MAIN SECTIONS */

section {
    max-width: 1000px;
    margin: 30px auto;
    background-color: white;
    padding: 30px;
    border-radius: 12px;
    box-sizing: border-box;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.06);
}

h2 {
    color: #232f3e;
    margin-top: 0;
    padding-bottom: 8px;
    border-bottom: 2px solid #f0f4f8;
}

p {
    line-height: 1.6;
}


/* SKILLS */

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.skill-list span {
    background-color: #e8f0fe;
    padding: 10px 14px;
    border-radius: 20px;
    font-weight: bold;
}

.next-focus .skill-list span {
    background-color: #fff3df;
    color: #232f3e;
}

.next-focus p {
    margin-top: 20px;
}


/* ARCHITECTURE */

.architecture-diagram {
    text-align: center;
    margin-top: 30px;
    margin-bottom: 25px;
}

.architecture-box {
    background-color: #232f3e;
    color: white;
    padding: 15px;
    margin: 10px auto;
    max-width: 250px;
    border-radius: 8px;
    font-weight: bold;
}

.architecture-arrow {
    font-size: 28px;
    font-weight: bold;
    color: #ff9900;
}


/* PROJECTS + ARTICLES */

.project-card,
.article-card {
    background-color: #f0f4f8;
    border-left: 5px solid #ff9900;
    padding: 20px;
    margin: 18px 0;
    border-radius: 8px;
    transition:
        transform 0.2s ease,
        box-shadow 0.2s ease;
}

.article-card {
    border-left-color: #232f3e;
}

.project-card:hover,
.article-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08);
}

.project-card h3,
.article-card h3 {
    margin-top: 0;
    margin-bottom: 10px;
    color: #232f3e;
}

.project-button {
    display: inline-block;
    background-color: #232f3e;
    color: white;
    padding: 10px 14px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: bold;
    margin-top: 10px;
    transition:
        background-color 0.2s ease,
        color 0.2s ease,
        transform 0.2s ease;
}

.project-button + .project-button {
    margin-left: 10px;
}

.project-button:hover {
    background-color: #ff9900;
    color: #232f3e;
    transform: translateY(-2px);
}


/* FOOTER */

footer {
    text-align: center;
    background-color: #232f3e;
    color: white;
    padding: 25px 20px;
    margin-top: 40px;
}

footer p {
    margin: 8px 0;
}

footer a {
    color: #ff9900;
    text-decoration: none;
    font-weight: bold;
}

footer a:hover {
    text-decoration: underline;
}


/* MOBILE RESPONSIVENESS */

@media (max-width: 768px) {

    .hero {
        padding: 50px 20px;
    }

    .profile-photo {
        width: 150px;
        height: 150px;
    }

    .hero h1 {
        font-size: 38px;
    }

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

    .hero-subtitle {
        font-size: 15px;
        line-height: 1.5;
    }

    section {
        margin: 20px 15px;
        padding: 24px 20px;
    }

    .skill-list {
        gap: 10px;
    }

    .skill-list span {
        font-size: 14px;
    }

    .architecture-box {
        max-width: 220px;
    }
}


@media (max-width: 480px) {

    .hero h1 {
        font-size: 32px;
    }

    .hero-title {
        font-size: 18px;
    }

    .profile-photo {
        width: 135px;
        height: 135px;
    }

    .button {
        padding: 11px 18px;
    }

    section {
        margin: 15px 10px;
        padding: 22px 18px;
    }

    .project-card,
    .article-card {
        padding: 16px;
    }

    .project-button {
        display: block;
        width: fit-content;
    }

    .project-button + .project-button {
        margin-left: 0;
    }
}
```