* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --text: #1f2937;
    --text-light: #6b7280;
    --background: #ffffff;
    --surface: #f9fafb;
    --border: #e5e7eb;
}

/* Dark Mode */
body.dark-mode {
    --primary: #60a5fa;
    --primary-dark: #3b82f6;
    --text: #f3f4f6;
    --text-light: #9ca3af;
    --background: #111827;
    --surface: #1f2937;
    --border: #374151;
}

body.dark-mode .banner {
    background: linear-gradient(135deg, #065f46 0%, #047857 100%);
}

body.dark-mode .hero {
    background-color: #1f2937;
    background-image:
        linear-gradient(30deg, #374151 12%, transparent 12.5%, transparent 87%, #374151 87.5%, #374151),
        linear-gradient(150deg, #374151 12%, transparent 12.5%, transparent 87%, #374151 87.5%, #374151),
        linear-gradient(30deg, #374151 12%, transparent 12.5%, transparent 87%, #374151 87.5%, #374151),
        linear-gradient(150deg, #374151 12%, transparent 12.5%, transparent 87%, #374151 87.5%, #374151),
        linear-gradient(60deg, #4b556377 25%, transparent 25.5%, transparent 75%, #4b556377 75%, #4b556377),
        linear-gradient(60deg, #4b556377 25%, transparent 25.5%, transparent 75%, #4b556377 75%, #4b556377);
}

body.dark-mode .cert-thumbnail img {
    border-color: var(--border);
}

/* Dark Mode Toggle */
.theme-toggle {
    position: absolute;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 6px;
    padding: 6px 10px;
    cursor: pointer;
    font-size: 1.1rem;
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    color: var(--text);
    line-height: 1.6;
}

/* Banner */
.banner {
    background: linear-gradient(135deg, #059669 0%, #10b981 100%);
    color: white;
    padding: 12px 0;
    text-align: center;
    position: relative;
}

.banner-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.banner span {
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.5px;
}

/* Navbar */
.navbar {
    background: var(--background);
    border-bottom: 1px solid var(--border);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 25px;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Hero Section */
.hero {
    background-color: #f0fdf4;
    background-image:
        linear-gradient(30deg, #d1fae5 12%, transparent 12.5%, transparent 87%, #d1fae5 87.5%, #d1fae5),
        linear-gradient(150deg, #d1fae5 12%, transparent 12.5%, transparent 87%, #d1fae5 87.5%, #d1fae5),
        linear-gradient(30deg, #d1fae5 12%, transparent 12.5%, transparent 87%, #d1fae5 87.5%, #d1fae5),
        linear-gradient(150deg, #d1fae5 12%, transparent 12.5%, transparent 87%, #d1fae5 87.5%, #d1fae5),
        linear-gradient(60deg, #a7f3d077 25%, transparent 25.5%, transparent 75%, #a7f3d077 75%, #a7f3d077),
        linear-gradient(60deg, #a7f3d077 25%, transparent 25.5%, transparent 75%, #a7f3d077 75%, #a7f3d077);
    background-size: 80px 140px;
    background-position: 0 0, 0 0, 40px 70px, 40px 70px, 0 0, 40px 70px;
    border-bottom: 1px solid var(--border);
    padding: 100px 0;
    text-align: center;
    position: relative;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text);
}

.tagline {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 25px;
}

.social-links {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.social-links a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border: 1px solid var(--primary);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.social-links a:hover {
    background: var(--primary);
    color: white;
}

/* Main Content */
main {
    padding: 60px 0;
}

section {
    margin-bottom: 60px;
}

h2 {
    font-size: 1.75rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border);
}

/* About Section */
.about p {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 700px;
}

/* Projects Grid */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
}

.project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 25px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.project-card h3 {
    font-size: 1.25rem;
    margin-bottom: 10px;
}

.project-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 15px;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 15px;
}

.tag {
    background: var(--border);
    color: var(--text-light);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
}

.project-links {
    display: flex;
    gap: 15px;
}

.project-links a {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.project-links a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 30px 0;
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Certifications Section */
.certifications {
    margin-top: 40px;
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.cert-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    gap: 15px;
    align-items: flex-start;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cert-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.cert-icon {
    font-size: 2rem;
    line-height: 1;
}

.cert-thumbnail {
    flex-shrink: 0;
}

.cert-thumbnail img {
    width: 80px;
    height: auto;
    border-radius: 6px;
    border: 1px solid var(--border);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.cert-info {
    flex: 1;
}

.cert-info h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: var(--text);
}

.cert-issuer {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 3px;
}

.cert-date {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.cert-info a {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.cert-info a:hover {
    text-decoration: underline;
}

/* Education Section */
.education {
    margin-top: 40px;
}

.education-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.edu-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 25px;
    display: flex;
    gap: 20px;
    align-items: flex-start;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.edu-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.edu-icon {
    font-size: 2.5rem;
    line-height: 1;
    flex-shrink: 0;
}

.edu-icon img {
    width: 60px;
    height: 60px;
    border-radius: 8px;
    object-fit: cover;
}

.edu-info {
    flex: 1;
}

.edu-info h3 {
    font-size: 1.25rem;
    margin-bottom: 5px;
    color: var(--text);
}

.edu-degree {
    font-size: 1.05rem;
    color: var(--text);
    margin-bottom: 3px;
}

.edu-field {
    color: var(--primary);
    font-size: 0.95rem;
    margin-bottom: 3px;
}

.edu-years {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.edu-description {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Blog Page */
.blog-page {
    padding: 40px 0;
}

.blog-page h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.blog-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.blog-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 30px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.blog-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.blog-date {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.blog-card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    border-bottom: none;
    padding-bottom: 0;
}

.blog-summary {
    color: var(--text-light);
    font-size: 1rem;
    margin-bottom: 15px;
}

.blog-tags {
    margin-bottom: 20px;
}

.blog-content {
    color: var(--text);
    line-height: 1.8;
    border-top: 1px solid var(--border);
    padding-top: 20px;
}

.blog-content p {
    margin-bottom: 15px;
}

/* Comments Section */
.comments-section {
    margin-top: 50px;
    padding-top: 30px;
    border-top: 2px solid var(--border);
}

.comments-section h2 {
    margin-bottom: 20px;
}

#giscus-container {
    background: var(--surface);
    border-radius: 12px;
    padding: 20px;
}

/* Projects Page */
.projects-page {
    padding: 40px 0;
}

.projects-page h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.projects-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.projects-page .project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.project-screenshot {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.project-screenshot img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-screenshot.placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder-icon {
    font-size: 4rem;
    opacity: 0.8;
}

.projects-page .project-info {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.projects-page .project-info h2 {
    font-size: 1.4rem;
    margin-bottom: 10px;
    border-bottom: none;
    padding-bottom: 0;
}

.projects-page .project-info > p {
    color: var(--text-light);
    margin-bottom: 15px;
    flex: 1;
}

.projects-page .project-tags {
    margin-bottom: 20px;
}

.projects-page .project-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn-primary {
    background: var(--primary);
    color: white !important;
    padding: 10px 20px;
    border-radius: 8px;
    text-decoration: none !important;
    font-weight: 500;
    transition: background 0.2s ease;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--surface);
    color: var(--text) !important;
    padding: 10px 20px;
    border-radius: 8px;
    border: 1px solid var(--border);
    text-decoration: none !important;
    font-weight: 500;
    transition: all 0.2s ease;
}

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

/* Testimonials Page */
.testimonials-page {
    padding: 40px 0;
}

.testimonials-page h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.section-intro {
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 40px;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 25px;
}

.testimonial-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 30px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.testimonial-content {
    margin-bottom: 20px;
}

.testimonial-content p {
    font-size: 1.05rem;
    color: var(--text);
    line-height: 1.7;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 15px;
    padding-top: 15px;
    border-top: 1px solid var(--border);
}

.author-info {
    display: flex;
    flex-direction: column;
}

.author-info strong {
    color: var(--text);
    font-size: 1rem;
}

.author-info span {
    color: var(--text-light);
    font-size: 0.9rem;
}

.author-info .company {
    color: var(--primary);
    font-size: 0.85rem;
}

.no-content {
    color: var(--text-light);
    text-align: center;
    padding: 40px;
}

/* Responsive */
@media (max-width: 600px) {
    .hero {
        padding: 50px 0;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

    .project-grid {
        grid-template-columns: 1fr;
    }

    .testimonials-grid {
        grid-template-columns: 1fr;
    }

    .nav-brand {
        font-size: 1rem;
    }

    .nav-links {
        gap: 15px;
    }
}