body {
    background: linear-gradient(135deg, #e8e8e8 0%, #d4e7f5 100%);
    color: #1a2e2e;
    min-height: 100vh;
}

.top-nav {
    position: fixed;
    top: 24px;
    left: 50%;
    transform: translateX(-50%);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 0.75rem 1.5rem;
    background: #0d4d4d;
    border-radius: 50px;
    box-shadow: 0 10px 24px rgba(13, 77, 77, 0.2);
    z-index: 100;
}

.back-link {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 999px;
    transition: all 0.2s ease;
}

.back-link:hover {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.1);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 120px 24px 48px;
}

.page-header {
    text-align: center;
    margin-bottom: 2rem;
}

.page-header h1 {
    font-size: 2rem;
    color: #0d4d4d;
    margin-bottom: 0.5rem;
}

.page-header p {
    color: #4a5e5e;
}

.page-header a {
    color: #0d4d4d;
    font-weight: 600;
}

/* Section Titles */
.section-title {
    font-size: 1.5rem;
    color: #0d4d4d;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid rgba(13, 77, 77, 0.1);
}

/* Projects Section */
.projects-section {
    margin-bottom: 3rem;
}

/* Projects Grid */
#projects-grid,
#challenges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

/* Project Card */
.project-card {
    background: #ffffff;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 12px rgba(13, 77, 77, 0.1);
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(13, 77, 77, 0.15);
}

.project-card h3 {
    color: #0d4d4d;
    margin-bottom: 0.5rem;
}

.project-card .description {
    color: #4a5e5e;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

/* Highlights List */
.highlights {
    list-style: disc;
    padding-left: 1.25rem;
}

.highlights li {
    color: #4a5e5e;
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 0.4rem;
}

.highlights li:last-child {
    margin-bottom: 0;
}

/* Category Badges */
.badges {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.badge {
    padding: 0.35rem 0.75rem;
    background: rgba(13, 77, 77, 0.08);
    color: #0d4d4d;
    border-radius: 999px;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

/* Tech Stack */
.tech-stack {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tech-stack span {
    padding: 0.35rem 0.6rem;
    background: #f1f6f8;
    color: #4a5e5e;
    border-radius: 8px;
    font-size: 0.75rem;
}

/* GitHub Link */
.btn-github {
    display: inline-block;
    padding: 0.75rem 1.25rem;
    background: #0d4d4d;
    color: white;
    text-decoration: none;
    border-radius: 999px;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    text-align: center;
}

.btn-github:hover {
    background: #0a3d3d;
    transform: translateY(-2px);
}

/* Loading State */
.loading {
    grid-column: 1 / -1;
    text-align: center;
    color: #4a5e5e;
    padding: 3rem 1.5rem;
}

/* Achievements Section */
.achievements-section {
    margin-top: 2rem;
}

.achievements-grid-wrapper {
    padding: 2rem;
    background: #ffffff;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(13, 77, 77, 0.1);
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    justify-items: center;
}

.achievement-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: #1a2e2e;
    background: #f5f7f7;
    border-radius: 12px;
    padding: 1.25rem;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    max-width: 280px;
    width: 100%;
}

.achievement-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(13, 77, 77, 0.15);
}

.achievement-image {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

.achievement-image.badge-image {
    max-width: 180px;
}

.achievement-image.cert-image {
    max-width: 220px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.achievement-label {
    margin-top: 0.75rem;
    font-size: 0.9rem;
    font-weight: 600;
    color: #0d4d4d;
    text-align: center;
}

/* Focus States */
.btn-github:focus-visible,
.back-link:focus-visible,
.achievement-card:focus-visible {
    outline: 2px solid #0d4d4d;
    outline-offset: 2px;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 100px 16px 40px;
    }

    .top-nav {
        top: 16px;
    }

    .achievements-grid-wrapper {
        padding: 1.5rem;
    }

    .achievement-image.badge-image {
        max-width: 150px;
    }

    .achievement-image.cert-image {
        max-width: 180px;
    }
}