/* styles.css */
:root {
    /* Light theme variables */
    --light-bg: #f8f9fa;
    --light-text: #212529;
    --light-card: #ffffff;
    --light-nav: #ffffff;
    --light-primary: #333333;
    --light-secondary: #6c757d;
    --light-accent: #6c757d;
    --light-shadow: rgba(0, 0, 0, 0.1);
    --light-border: #e9ecef;
    --light-hero-bg: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    
    /* Dark theme variables */
    --dark-bg: #121212;
    --dark-text: #e0e0e0;
    --dark-card: #1e1e1e;
    --dark-nav: #1a1a1a;
    --dark-primary: #cccccc;
    --dark-secondary: #a0a0a0;
    --dark-shadow: rgba(0, 0, 0, 0.3);
    --dark-border: #2d2d2d;
    --dark-hero-bg: linear-gradient(135deg, #0f0f0f 0%, #2a2a2a 100%);
    
    /* Common variables */
    --transition: all 0.3s ease;
    --border-radius: 12px;
    --section-padding: 80px 20px;
    --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --hover-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
}

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

body {
    font-family: 'Roboto', sans-serif;
    background: var(--light-bg);
    color: var(--light-text);
    font-size: 18px;
    line-height: 1.6;
    transition: var(--transition);
}

body.dark-theme {
    background: var(--dark-bg);
    color: var(--dark-text);
}

/* Theme toggle button */
.theme-toggle {
    position: fixed;
    top: 10px;
    right: 20px;
    z-index: 1000;
}

#theme-btn {
    background: var(--light-primary);
    color: white;
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
}

#theme-btn .fa-sun,
#theme-btn .fa-moon {
    position: absolute;
    transition: var(--transition);
}

#theme-btn .fa-moon {
    opacity: 0;
    transform: translateY(20px);
}

body.dark-theme #theme-btn {
    background: var(--dark-primary);
}

body.dark-theme #theme-btn .fa-sun {
    opacity: 0;
    transform: translateY(-20px);
}

body.dark-theme #theme-btn .fa-moon {
    opacity: 1;
    transform: translateY(0);
}

/* Topbar styles */
.topbar {
    background: var(--light-nav);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px var(--light-shadow);
    transition: var(--transition);
}

body.dark-theme .topbar {
    background: var(--dark-nav);
    box-shadow: 0 2px 10px var(--dark-shadow);
}

.logo {
    font-family: 'Poppins', sans-serif;
    font-weight: 700;
    font-size: 24px;
    color: var(--light-primary);
}

body.dark-theme .logo {
    color: var(--dark-primary);
}

.nav-links a {
    color: var(--light-text);
    text-decoration: none;
    margin: 0 15px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 5px 0;
}

body.dark-theme .nav-links a {
    color: var(--dark-text);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--light-primary);
    transition: var(--transition);
}

body.dark-theme .nav-links a::after {
    background: var(--dark-primary);
}

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

body.dark-theme .nav-links a:hover {
    color: var(--dark-primary);
}

.nav-links a:hover::after {
    width: 100%;
}

/* Hero section */
.hero {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 100px 5% 50px;
    background: var(--light-hero-bg);
    transition: var(--transition);
}

body.dark-theme .hero {
    background: var(--dark-hero-bg);
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-image {
    flex: 1;
    position: relative;
    display: flex;
    justify-content: center;
}

.circle {
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: var(--light-primary);
    opacity: 0.1;
    position: absolute;
    z-index: 0;
    animation: pulse 8s infinite ease-in-out;
}

.pattern {
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, transparent 20%, var(--light-bg) 70%);
    z-index: 1;
}

body.dark-theme .pattern {
    background: radial-gradient(circle, transparent 20%, var(--dark-bg) 70%);
}

.code-snippet {
    position: relative;
    z-index: 2;
    background: var(--light-card);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    width: 90%;
    max-width: 500px;
    margin-top: 50px;
    transition: var(--transition);
}

body.dark-theme .code-snippet {
    background: var(--dark-card);
    box-shadow: 0 10px 30px var(--dark-shadow);
}

.code-snippet pre {
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 16px;
    color: var(--light-text);
    line-height: 1.5;
}

body.dark-theme .code-snippet pre {
    color: var(--dark-text);
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero h2 {
    font-size: 2rem;
    margin-bottom: 25px;
    font-weight: 400;
    color: var(--light-secondary);
}

body.dark-theme .hero h2 {
    color: var(--dark-secondary);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 35px;
    max-width: 500px;
}

.highlight {
    color: var(--light-primary);
    position: relative;
}

body.dark-theme .highlight {
    color: var(--dark-primary);
}

.hero-btns {
    display: flex;
    gap: 20px;
}

.btn {
    padding: 14px 32px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-block;
    border: 2px solid transparent;
}

.btn.primary {
    background: var(--light-primary);
    color: white;
    box-shadow: 0 5px 15px rgba(78, 84, 200, 0.3);
}

.btn.primary:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(78, 84, 200, 0.4);
}

.btn.secondary {
    background: transparent;
    color: var(--light-primary);
    border-color: var(--light-primary);
}

.btn.secondary:hover {
    background: rgba(78, 84, 200, 0.1);
    transform: translateY(-5px);
}

body.dark-theme .btn.secondary {
    color: var(--dark-primary);
    border-color: var(--dark-primary);
}

body.dark-theme .btn.secondary:hover {
    background: rgba(106, 125, 224, 0.1);
}

/* Skills section */
.skills-section {
    padding: var(--section-padding);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
    position: relative;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.section-title.visible {
    opacity: 1;
    transform: translateY(0);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--light-primary);
    border-radius: 2px;
}

body.dark-theme .section-title::after {
    background: var(--dark-primary);
}

.skills-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.skill-card {
    background: var(--light-card);
    border-radius: var(--border-radius);
    padding: 40px 30px;
    text-align: center;
    flex: 1;
    min-width: 300px;
    max-width: 350px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
}

body.dark-theme .skill-card {
    background: var(--dark-card);
    box-shadow: 0 10px 30px var(--dark-shadow);
}

.skill-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.skill-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--hover-shadow);
}

.skill-icon {
    width: 80px;
    height: 80px;
    background: rgba(78, 84, 200, 0.1);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 auto 25px;
    font-size: 32px;
    color: var(--light-primary);
    transition: var(--transition);
}

body.dark-theme .skill-icon {
    background: rgba(106, 125, 224, 0.1);
    color: var(--dark-primary);
}

.skill-card:hover .skill-icon {
    background: var(--light-primary);
    color: white;
    transform: scale(1.1);
}

body.dark-theme .skill-card:hover .skill-icon {
    background: var(--dark-primary);
}

.skill-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--light-text);
}

body.dark-theme .skill-card h3 {
    color: var(--dark-text);
}

.skill-card p {
    color: var(--light-secondary);
}

body.dark-theme .skill-card p {
    color: var(--dark-secondary);
}

/* Projects section */
.projects-section {
    padding: var(--section-padding);
    background: rgba(248, 249, 250, 0.5);
    transition: var(--transition);
}

body.dark-theme .projects-section {
    background: rgba(18, 18, 18, 0.5);
}

.projects-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
}

.project-card {
    background: var(--light-card);
    border-radius: var(--border-radius);
    overflow: hidden;
    flex: 1;
    min-width: 300px;
    max-width: 380px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
}

body.dark-theme .project-card {
    background: var(--dark-card);
    box-shadow: 0 10px 30px var(--dark-shadow);
}

.project-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--hover-shadow);
}

.project-image {
    height: 220px;
    position: relative;
    display: flex;
    align-items: flex-end;
    padding: 20px;
    color: white;
}

.project-tech {
    background: rgba(0, 0, 0, 0.7);
    padding: 8px 15px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
}

.project-content {
    padding: 30px;
}

.project-content h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--light-text);
}

body.dark-theme .project-content h3 {
    color: var(--dark-text);
}

.project-content p {
    color: var(--light-secondary);
    margin-bottom: 25px;
}

body.dark-theme .project-content p {
    color: var(--dark-secondary);
}

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

.project-link {
    color: var(--light-primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding-bottom: 2px;
    border-bottom: 2px solid transparent;
}

body.dark-theme .project-link {
    color: var(--dark-primary);
}

.project-link:hover {
    border-bottom: 2px solid var(--light-primary);
}

body.dark-theme .project-link:hover {
    border-bottom: 2px solid var(--dark-primary);
}

/* Contact section */
.contact-section {
    padding: var(--section-padding);
    transition: var(--transition);
}

.contact-container {
    display: flex;
    flex-wrap: wrap;
    gap: 50px;
    max-width: 1200px;
    margin: 0 auto;
    justify-content: center;
}

.contact-info {
    flex: 1;
    min-width: 300px;
    max-width: 500px;
}

.contact-info p {
    margin-bottom: 30px;
    font-size: 1.1rem;
    line-height: 1.8;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.contact-link {
    display: flex;
    align-items: center;
    color: var(--light-text);
    text-decoration: none;
    transition: var(--transition);
    font-size: 1.1rem;
}

body.dark-theme .contact-link {
    color: var(--dark-text);
}

.contact-link i {
    font-size: 1.5rem;
    margin-right: 15px;
    color: var(--light-primary);
    transition: var(--transition);
}

body.dark-theme .contact-link i {
    color: var(--dark-primary);
}

.contact-link:hover {
    color: var(--light-primary);
    transform: translateX(10px);
}

body.dark-theme .contact-link:hover {
    color: var(--dark-primary);
}

.contact-link:hover i {
    transform: scale(1.2);
}

.contact-form {
    flex: 1;
    min-width: 300px;
    max-width: 500px;
    background: var(--light-card);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    transition: var(--transition);
}

body.dark-theme .contact-form {
    background: var(--dark-card);
    box-shadow: 0 10px 30px var(--dark-shadow);
}

.form-group {
    margin-bottom: 25px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 1px solid var(--light-border);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--light-card);
    color: var(--light-text);
    transition: var(--transition);
}

body.dark-theme .form-group input,
body.dark-theme .form-group textarea {
    border-color: var(--dark-border);
    background: var(--dark-card);
    color: var(--dark-text);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--light-primary);
    box-shadow: 0 0 0 3px rgba(78, 84, 200, 0.2);
}

body.dark-theme .form-group input:focus,
body.dark-theme .form-group textarea:focus {
    border-color: var(--dark-primary);
    box-shadow: 0 0 0 3px rgba(106, 125, 224, 0.2);
}

/* Footer */
footer {
    background: var(--light-nav);
    padding: 60px 5% 30px;
    transition: var(--transition);
}

body.dark-theme footer {
    background: var(--dark-nav);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto 40px;
    display: flex;
    flex-wrap: wrap;
    gap: 50px;
    justify-content: space-between;
}

.footer-logo {
    font-family: 'Poppins', sans-serif;
    font-weight: 700;
    font-size: 28px;
    color: var(--light-primary);
    margin-bottom: 20px;
}

body.dark-theme .footer-logo {
    color: var(--dark-primary);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-links a {
    color: var(--light-text);
    text-decoration: none;
    transition: var(--transition);
}

body.dark-theme .footer-links a {
    color: var(--dark-text);
}

.footer-links a:hover {
    color: var(--light-primary);
}

body.dark-theme .footer-links a:hover {
    color: var(--dark-primary);
}

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

.social-links a {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background: var(--light-card);
    color: var(--light-text);
    transition: var(--transition);
    text-decoration: none;
    font-size: 1.2rem;
}

body.dark-theme .social-links a {
    background: var(--dark-card);
    color: var(--dark-text);
}

.social-links a:hover {
    background: var(--light-primary);
    color: white;
    transform: translateY(-5px);
}

body.dark-theme .social-links a:hover {
    background: var(--dark-primary);
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--light-border);
    color: var(--light-secondary);
    font-size: 0.9rem;
}

body.dark-theme .copyright {
    border-color: var(--dark-border);
    color: var(--dark-secondary);
}

/* Animations */
@keyframes pulse {
    0% { transform: scale(0.95); opacity: 0.1; }
    50% { transform: scale(1); opacity: 0.15; }
    100% { transform: scale(0.95); opacity: 0.1; }
}

.fadeIn {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fadeIn.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive design */
@media (max-width: 992px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding: 120px 5% 80px;
    }
    
    .hero-content {
        margin-bottom: 60px;
    }
    
    .hero-btns {
        justify-content: center;
    }
    
    .hero-image {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .topbar {
        flex-direction: column;
        gap: 20px;
    }
    
    .nav-links {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero h1 {
        font-size: 2.8rem;
    }
    
    .hero h2 {
        font-size: 1.6rem;
    }
    
    .contact-container {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 40px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2.3rem;
    }
    
    .hero-btns {
        flex-direction: column;
        gap: 15px;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
}

/* About section */
.about-section {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--section-padding);
}

.about-container {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

/* Profile container */
.profile-container {
    display: flex;
    align-items: center;
    gap: 40px;
    margin-bottom: 40px;
}

/* Paragraph cards */
.about-paragraphs {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.paragraph-card {
    background: var(--light-card);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
}

body.dark-theme .paragraph-card {
    background: var(--dark-card);
    box-shadow: 0 10px 30px var(--dark-shadow);
}

.paragraph-card.visible {
    opacity: 1;
    transform: translateY(0);
}

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

.paragraph-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--light-primary);
}

body.dark-theme .paragraph-card h3 {
    color: var(--dark-primary);
}

.paragraph-card h3 i {
    font-size: 1.2rem;
}

.paragraph-card p {
    color: var(--light-secondary);
    line-height: 1.8;
    margin-bottom: 15px;
}

body.dark-theme .paragraph-card p {
    color: var(--dark-secondary);
}

/* Back button */
.back-btn {
    display: inline-flex;
    align-items: center;
    color: var(--light-text);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 4px;
    transition: var(--transition);
    background: rgba(0, 0, 0, 0.05);
}

body.dark-theme .back-btn {
    color: var(--dark-text);
    background: rgba(255, 255, 255, 0.05);
}

.back-btn i {
    margin-right: 8px;
    transition: var(--transition);
}

.back-btn:hover {
    background: rgba(0, 0, 0, 0.1);
    color: var(--light-primary);
}

body.dark-theme .back-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--dark-primary);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .profile-container {
        flex-direction: column;
        text-align: center;
    }
    
    .about-header h1 {
        font-size: 2.3rem;
    }
    
    .profile-content h2 {
        font-size: 1.5rem;
    }
    
    .profile-content p {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .about-header h1 {
        font-size: 2rem;
    }
    
    .profile-image {
        width: 150px;
        height: 150px;
    }
    
    .profile-image .initials {
        font-size: 3.5rem;
    }
    
    .about-section {
        padding: 60px 15px;
    }
}