:root {
    --primary-color: #3b82f6;
    --secondary-color: #1d4ed8;
    --accent-color: #06b6d4;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --light-bg: #f8fafc;
    --white: #ffffff;
    --gradient-start: #3b82f6;
    --gradient-end: #06b6d4;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --nav-bg: rgba(255, 255, 255, 0.8);
    --nav-border: rgba(229, 231, 235, 1);
    --nav-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --hover-bg: rgba(243, 244, 246, 1);
    --focus-ring: rgba(59, 130, 246, 0.5);
    --card-hover-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* Navigation Styles */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background-color: var(--nav-bg);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--nav-border);
    box-shadow: var(--nav-shadow);
    transition: all 0.3s ease-in-out;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Language Switcher */
.language-switcher {
    margin-left: 1.5rem;
    position: relative;
}

.switcher-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.switcher-wrapper i {
    position: absolute;
    right: 0.75rem;
    color: var(--text-light);
    pointer-events: none;
    font-size: 0.9rem;
}

.language-switcher select {
    padding: 0.5rem 2.5rem 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: inherit;
    color: var(--text-color);
    cursor: pointer;
    font-size: 0.9rem;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    transition: all 0.2s ease;
}

.language-switcher select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(var(--primary-rgb), 0.1);
}



.language-switcher select:hover {
    transform: translateY(-1px);
    box-shadow: var(--card-shadow);
}

.nav-content {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.nav-brand a {
    display: flex;
    align-items: center;
    text-decoration: none;
    padding: 0.75rem 0;
    color: var(--text-color);
}

.nav-brand .nav-logo {
    width: 36px;
    height: 36px;
    transition: transform 0.2s ease;
}

@media (max-width: 768px) {
    .nav-brand .nav-logo {
        width: 28px;
        height: 28px;
    }
}

.nav-brand a:hover .nav-logo {
    transform: scale(1.1);
}

.nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    border-radius: 0.375rem;
    color: var(--text-light);
    background: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.nav-toggle:hover {
    color: var(--text-color);
    background-color: var(--hover-bg);
}

.nav-toggle:focus {
    outline: none;
    box-shadow: 0 0 0 2px var(--focus-ring);
}

.nav-toggle svg {
    width: 1.5rem;
    height: 1.5rem;
}

.nav-menu {
    overflow: hidden;
    transition: all 0.3s ease-in-out;
}

.nav-menu-items {
    display: flex;
    flex-direction: column;
    width: 100%;
    transition: opacity 0.2s ease-in-out;
}

/* Base styles for navigation links */
.nav-link {
    text-decoration: none;          /* Remove default underline */
    color: var(--text-color);       /* Use theme text color */
    font-weight: 500;               /* Medium font weight for better readability */
    transition: color 0.3s ease;    /* Smooth transition for text color only */
    padding: 0.5rem 1rem;           /* Comfortable padding for clickable area */
    border-radius: 6px;             /* Slightly rounded corners */
    position: relative;             /* Enable positioning for the underline effect */
}

/* Desktop: Gradient underline effect using pseudo-element */
@media (min-width: 768px) {
    .nav-link::after {
        content: '';
        position: absolute;
        bottom: 0;
        left: 50%;
        transform: translateX(-50%);
        width: 0;
        height: 2px;
        background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
        transition: width 0.3s ease;
    }

    .nav-link:hover::after {
        width: 80%;
    }
}

/* Mobile: Simple background effect on hover */
@media (max-width: 768px) {
    .nav-link {
        transition: background-color 0.2s ease;
    }

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

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

/* Desktop styles */
@media (min-width: 768px) {
    .nav-container {
        padding: 0 1.5rem;
    }

    .nav-content {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        height: 4rem;
    }

    .nav-toggle {
        display: none;
    }

    .nav-menu {
        height: auto !important;
        overflow: visible;
        margin-left: auto;
    }

    .nav-menu-items {
        flex-direction: row;
        align-items: center;
        gap: 1rem;
        padding: 0;
    }

    .nav-link {
        margin: 0;
        font-size: 0.875rem;
        padding: 0.5rem 0.75rem;
    }

    .nav-brand a {
        padding: 0;
    }
}

@media (min-width: 1024px) {
    .nav-container {
        padding: 0 2rem;
    }
}

@media (max-width: 768px) {
    .nav-content {
        flex-direction: row;
        align-items: center;
    }

    .nav-content.mobile-menu-open {
        flex-direction: column;
        align-items: flex-start;
        height: auto;
    }

    .mobile-menu-open .nav-toggle {
        display: none;
    }

    .nav-menu {
        width: 100%;
    }

    .nav-menu-items {
        flex-direction: column;
        width: 100%;
        padding: 0.5rem 0;
    }

    .nav-menu-items .nav-link {
        padding: 0.75rem 0;
        width: 100%;
        border-radius: 0;
    }

    .language-switcher {
        display: none;
    }

    .nav-menu .language-switcher {
        display: block;
        margin: 0.5rem 0;
        width: 100%;
        order: 1;
    }

    .switcher-wrapper {
        width: 100%;
    }

    .language-switcher select {
        width: 100%;
        padding: 0.75rem 2.5rem 0.75rem 1rem;
        font-size: 1rem;
        background: inherit;
        border-radius: 8px;
    }

    .switcher-wrapper i {
        font-size: 1rem;
    }

    .mobile-hidden {
        display: none !important;
    }

    .mobile-visible {
        display: block !important;
    }
}

/* Mobile utility classes */
@media (max-width: 768px) {
    .mobile-hidden {
        display: none;
    }
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-bg);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Navigation */
header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: flex-end;
    padding: 1rem 0;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    position: relative;
}

nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    transition: width 0.3s ease;
}

nav ul li a:hover::after {
    width: 80%;
}

nav ul li a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: var(--white);
    padding: 10rem 0 6rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 60%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    letter-spacing: -0.025em;
    position: relative;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.tech-stack {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
}

.tech-stack i, .tech-stack .icon-text {
    font-size: 2.5rem;
    color: rgba(255, 255, 255, 0.9);
    transition: all 0.3s ease;
}

.tech-stack .icon-text {
    font-weight: bold;
    font-family: monospace;
}

.tech-stack i:hover,
.tech-stack .icon-text:hover {
    transform: scale(1.2);
    color: white;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

/* Skills Section */
.skills {
    padding: 4rem 0;
    background-color: var(--light-bg);
}

.skill-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.skill-card {
    background: var(--white);
    padding: 2.5rem 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.skill-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.skill-card:hover::before {
    opacity: 1;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-hover-shadow);
}

.skill-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Projects Section */
.projects {
    padding: 4rem 0;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
    position: relative;
    border: 1px solid rgba(0,0,0,0.05);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-hover-shadow);
}

.project-content {
    padding: 1.5rem;
}

.preview-container {
    margin: 1.5rem 0;
}

.preview-toggle {
    width: 100%;
    padding: 0.75rem;
    background: var(--light-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.preview-toggle:hover {
    background: var(--border-color);
}

.preview-toggle i {
    font-size: 1rem;
}

.codepen-preview {
    margin-top: 1rem;
    background: #1d1d1d;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.project-content h3 {
    margin-bottom: 0.5rem;
}

.project-links {
    margin-top: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.project-links a {
    position: relative;
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    background: var(--white);
    border: 1px solid var(--nav-border);
    transition: transform 0.2s ease, border-color 0.2s ease;
    overflow: hidden;
}

.project-links a::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    opacity: 0;
    transition: opacity 0.2s ease;
    z-index: 1;
}

.project-links a span {
    position: relative;
    z-index: 2;
    transition: color 0.2s ease;
}

.project-links a:hover {
    transform: translateY(-1px);
    border-color: transparent;
    box-shadow: var(--card-shadow);
}

.project-links a:hover::before {
    opacity: 1;
}

.project-links a:hover span {
    color: var(--white);
}

/* Contact Section */
.contact {
    padding: 4rem 0;
    background-color: var(--light-bg);
    text-align: center;
}

.contact-links {
    margin-top: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 8px;
    margin: 0.5rem;
    background: var(--white);
    border: 1px solid var(--nav-border);
}

.contact-link img,
.contact-link .contact-icon {
    display: inline-block;
}

.contact-link.x {
    background-color: var(--text-color);
    padding: 0;
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s ease;
    box-shadow: var(--card-shadow);
}

.contact-link.wechat {
    background: none;
    padding: 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
}

.contact-link.x:hover,
.contact-link.wechat:hover {
    transform: translateY(-2px);
    box-shadow: var(--card-hover-shadow);
}

.contact-link.wechat img {
    width: 120px;
    height: 120px;
    object-fit: contain;
    display: block;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    z-index: 1100;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.show {
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 1;
}

.modal-content {
    position: relative;
    background-color: var(--white);
    padding: 1.5rem;
    border-radius: 12px;
    max-width: 90%;
    max-height: 90vh;
    box-shadow: var(--card-shadow);
    transform: scale(0.7);
    transition: transform 0.3s ease;
}

.modal.show .modal-content {
    transform: scale(1);
}

.modal-image {
    display: block;
    max-width: 100%;
    max-height: 80vh;
    width: auto;
    height: auto;
}

.close-modal {
    position: absolute;
    top: -1.5rem;
    right: -1.5rem;
    width: 2rem;
    height: 2rem;
    background-color: var(--white);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    font-size: 1.5rem;
    box-shadow: var(--card-shadow);
    transition: all 0.2s ease;
}

.close-modal:hover {
    background-color: var(--light-bg);
    transform: scale(1.1);
}

/* Footer */
/* Resume Link Styles */
.resume {
    padding: 4rem 0;
    background: var(--light-bg);
    text-align: center;
}

.resume-link {
    display: inline-flex;
    align-items: center;
    padding: 1rem 2rem;
    margin-top: 1rem;
    color: var(--text-color);
    text-decoration: none;
    border-radius: 8px;
    background: var(--white);
    border: 1px solid var(--nav-border);
    transition: all 0.3s ease;
}

.resume-link i {
    margin-right: 0.75rem;
    font-size: 1.25rem;
}

.resume-link:hover {
    transform: translateY(-2px);
    box-shadow: var(--card-shadow);
}



footer {
    background-color: var(--text-color);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    nav ul {
        justify-content: center;
    }
    
    nav ul li {
        margin: 0 1rem;
    }
}

/* Section Headers */
section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-color);
    font-size: 2.5rem;
    font-weight: 700;
    position: relative;
    padding-bottom: 1rem;
}

section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    border-radius: 2px;
}