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

:root {
    --header-height: 64px;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    --color-blue-50: #eff6ff;
    --color-blue-500: #3b82f6;
    --color-blue-600: #2563eb;
    --color-blue-700: #1d4ed8;
    --color-sky-50: #f0f9ff;
    --color-sky-700: #0369a1;
    --color-indigo-50: #eef2ff;
    --color-indigo-600: #4f46e5;
    --color-indigo-700: #4338ca;
    --color-indigo-900: #312e81;
    --color-green-50: #f0fdf4;
    --color-green-400: #4ade80;
    --color-green-600: #16a34a;
    --color-green-700: #15803d;
    --color-yellow-50: #fefce8;
    --color-yellow-600: #ca8a04;
    --color-purple-50: #faf5ff;
    --color-purple-700: #7e22ce;
    --color-white: #ffffff;
}

body {
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
    background-color: var(--color-gray-50);
    color: var(--color-gray-800);
    -webkit-font-smoothing: antialiased;
    line-height: 1.5;
}

section {
    scroll-margin-top: calc(var(--header-height) + 12px);
}

.container {
    max-width: 80rem;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) {
    .container {
        padding: 0 1.5rem;
    }
}

header {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 40;
}

.header-content {
    max-width: 80rem;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

@media (min-width: 640px) {
    .header-content {
        padding: 0 1.5rem;
    }
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

.logo-circle {
    width: 2.5rem;
    height: 2.5rem;
    background: linear-gradient(to top right, var(--color-blue-500), var(--color-indigo-600));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
    font-weight: 700;
}

.logo-text {
    display: none;
}

@media (min-width: 640px) {
    .logo-text {
        display: block;
    }
}

.logo-name {
    font-size: 1.125rem;
    font-weight: 600;
}

.logo-subtitle {
    font-size: 0.75rem;
    color: var(--color-gray-500);
    margin-top: -0.125rem;
}

.nav-desktop {
    display: none;
    align-items: center;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .nav-desktop {
        display: flex;
    }
}

.nav-link {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    text-decoration: none;
}

.nav-link:hover {
    color: var(--color-gray-900);
}

.mobile-menu {
    display: block;
}

@media (min-width: 640px) {
    .mobile-menu {
        display: none;
    }
}

.mobile-menu-btn {
    padding: 0.5rem;
    border-radius: 0.375rem;
    border: none;
    background: none;
    cursor: pointer;
}

.mobile-menu-btn:focus {
    outline: 2px solid var(--color-indigo-600);
}

.mobile-menu-icon {
    width: 1.5rem;
    height: 1.5rem;
    color: var(--color-gray-700);
}

.mobile-menu-dropdown {
    position: absolute;
    right: 1rem;
    top: 4rem;
    width: 12rem;
    background: var(--color-white);
    border-radius: 0.5rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.mobile-menu-nav {
    display: flex;
    flex-direction: column;
    padding: 0.5rem;
}

.mobile-menu-link {
    padding: 0.5rem 0.75rem;
    border-radius: 0.375rem;
    color: var(--color-gray-700);
    text-decoration: none;
}

.mobile-menu-link:hover {
    background-color: var(--color-gray-50);
}

main {
    max-width: 80rem;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) {
    main {
        padding: 0 1.5rem;
    }
}

.hero-section {
    margin-top: 2rem;
    background: linear-gradient(to right, var(--color-indigo-700), var(--color-blue-600), var(--color-indigo-700));
    color: var(--color-white);
    border-radius: 1rem;
    overflow: hidden;
}

.hero-content {
    display: flex;
    flex-direction: column-reverse;
    align-items: center;
    gap: 2rem;
    padding: 1.5rem;
}

@media (min-width: 640px) {
    .hero-content {
        padding: 2rem;
    }
}

@media (min-width: 1024px) {
    .hero-content {
        flex-direction: row;
        padding: 3rem;
    }
}

.hero-text {
    width: 100%;
    text-align: center;
}

@media (min-width: 1024px) {
    .hero-text {
        width: 50%;
        text-align: left;
    }
}

.hero-title {
    font-size: 1.875rem;
    font-weight: 800;
    line-height: 1.2;
}

@media (min-width: 640px) {
    .hero-title {
        font-size: 2.25rem;
    }
}

.hero-description {
    margin-top: 0.75rem;
    color: rgba(238, 242, 255, 0.9);
    max-width: 42rem;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 1024px) {
    .hero-description {
        margin-left: 0;
        margin-right: 0;
    }
}

.hero-buttons {
    margin-top: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

@media (min-width: 640px) {
    .hero-buttons {
        flex-direction: row;
        align-items: center;
    }
}

@media (min-width: 1024px) {
    .hero-buttons {
        justify-content: flex-start;
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border-radius: 0.375rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--color-white);
    color: var(--color-indigo-700);
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.btn-secondary {
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: var(--color-white);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

.hero-tags {
    margin-top: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem;
}

@media (min-width: 1024px) {
    .hero-tags {
        justify-content: flex-start;
    }
}

.tag {
    font-size: 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
}

.hero-image {
    width: 100%;
    display: flex;
    justify-content: center;
}

@media (min-width: 1024px) {
    .hero-image {
        width: 50%;
    }
}

.hero-circle {
    width: 10rem;
    height: 10rem;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
}

@media (min-width: 640px) {
    .hero-circle {
        width: 12rem;
        height: 12rem;
    }
}

.hero-icon {
    color: rgba(255, 255, 255, 0.9);
}

.section-card {
    margin-top: 2rem;
    background: var(--color-white);
    border-radius: 1rem;
    padding: 1.5rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
}

@media (min-width: 640px) {
    .section-card {
        padding: 2rem;
    }
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-gray-800);
}

.section-text {
    margin-top: 0.75rem;
    color: var(--color-gray-600);
    line-height: 1.625;
}

.about-grid {
    margin-top: 1rem;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

@media (min-width: 640px) {
    .about-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.about-card {
    padding: 0.75rem;
    background: var(--color-gray-50);
    border-radius: 0.5rem;
    text-align: center;
}

.about-card-title {
    font-size: 0.875rem;
    font-weight: 600;
}

.about-card-subtitle {
    font-size: 0.75rem;
    color: var(--color-gray-500);
}

.experience-section {
    margin-top: 2rem;
    display: grid;
    gap: 1.5rem;
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .experience-section {
        grid-template-columns: repeat(2, 1fr);
    }
}

.experience-card {
    background: var(--color-white);
    border-radius: 1rem;
    padding: 1.25rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
}

.experience-card.full-width {
    grid-column: 1 / -1;
}

.experience-content {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.experience-icon {
    flex-shrink: 0;
    width: 3rem;
    height: 3rem;
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.experience-icon.blue {
    background: var(--color-blue-50);
    color: var(--color-blue-600);
}

.experience-icon.green {
    background: var(--color-green-50);
    color: var(--color-green-600);
}

.experience-icon.yellow {
    background: var(--color-yellow-50);
    color: var(--color-yellow-600);
}

.experience-details {
    flex: 1;
}

.experience-title {
    font-size: 1.125rem;
    font-weight: 600;
}

.experience-subtitle {
    font-size: 0.875rem;
    color: var(--color-gray-500);
}

.experience-list {
    margin-top: 0.75rem;
    color: var(--color-gray-600);
    list-style: disc;
    padding-left: 1.5rem;
}

.experience-list li {
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.skills-tags {
    margin-top: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.875rem;
}

.skill-tag.blue {
    background: var(--color-blue-50);
    color: var(--color-blue-700);
}

.skill-tag.sky {
    background: var(--color-sky-50);
    color: var(--color-sky-700);
}

.skill-tag.indigo {
    background: var(--color-indigo-50);
    color: var(--color-indigo-700);
}

.skill-tag.gray {
    background: var(--color-gray-100);
    color: var(--color-gray-700);
}

.skill-tag.green {
    background: var(--color-green-50);
    color: var(--color-green-700);
}

.skill-tag.purple {
    background: var(--color-purple-50);
    color: var(--color-purple-700);
}

.skills-bars {
    margin-top: 1.5rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 640px) {
    .skills-bars {
        grid-template-columns: repeat(2, 1fr);
    }
}

.skill-bar-label {
    font-size: 0.875rem;
    color: var(--color-gray-500);
}

.skill-bar-container {
    width: 100%;
    background: var(--color-gray-100);
    border-radius: 9999px;
    height: 0.75rem;
    margin-top: 0.5rem;
    overflow: hidden;
}

.skill-bar {
    height: 0.75rem;
    border-radius: 9999px;
}

.skill-bar-frontend {
    background: linear-gradient(to right, var(--color-blue-500), var(--color-indigo-600));
    width: 78%;
}

.skill-bar-backend {
    background: linear-gradient(to right, var(--color-green-400), var(--color-green-600));
    width: 64%;
}

.contact-section {
    margin-top: 2rem;
    margin-bottom: 3rem;
    background: linear-gradient(to right, var(--color-gray-900), var(--color-indigo-900));
    color: var(--color-white);
    border-radius: 1rem;
    padding: 1.5rem;
}

@media (min-width: 640px) {
    .contact-section {
        padding: 2rem;
    }
}

.contact-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

@media (min-width: 640px) {
    .contact-content {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
}

.contact-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.contact-buttons {
    display: flex;
    gap: 0.75rem;
}

.btn-white {
    background: var(--color-white);
    color: var(--color-indigo-900);
    font-weight: 500;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
}

.btn-white:hover {
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.btn-outline-white {
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: var(--color-white);
}

.btn-outline-white:hover {
    background: rgba(255, 255, 255, 0.1);
}

footer {
    background: var(--color-white);
    margin-top: 1.5rem;
}

.footer-content {
    max-width: 80rem;
    margin: 0 auto;
    padding: 1.5rem 1rem;
    text-align: center;
    color: var(--color-gray-500);
    font-size: 0.875rem;
}

@media (min-width: 640px) {
    .footer-content {
        padding: 1.5rem 1.5rem;
    }
}

.scroll-top-btn {
    display: none;
    position: fixed;
    right: 1.5rem;
    bottom: 1.5rem;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    background: var(--color-indigo-600);
    color: var(--color-white);
    border-radius: 50%;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    text-decoration: none;
}

@media (min-width: 768px) {
    .scroll-top-btn {
        display: flex;
    }
}

.scroll-top-btn:hover {
    transform: scale(1.05);
}

.scroll-top-icon {
    width: 1.25rem;
    height: 1.25rem;
}

.floating-hidden {
    opacity: 0;
    transform: translateY(8px);
    pointer-events: none;
    transition: opacity .18s, transform .18s;
}

.floating-visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
    transition: opacity .18s, transform .18s;
}