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

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --accent: #2563eb;
    --border: #e5e7eb;
}

body.dark-mode {
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --border: #374151;
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

/* Navigation */
nav {
    position: sticky;
    top: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    z-index: 100;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

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

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

.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    width: 36px;
    height: 36px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle svg {
    width: 18px;
    height: 18px;
    fill: var(--text-primary);
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-toggle svg {
    width: 24px;
    height: 24px;
    fill: var(--text-primary);
}

/* Container */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 4rem 0;
}

/* Hero */
.hero {
    padding: 6rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.hero .subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.hero .description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    opacity: 0.9;
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.social-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.social-link {
    width: 40px;
    height: 40px;
    border: 1px solid var(--border);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.2s;
}

.social-link:hover {
    border-color: var(--accent);
}

.social-link svg {
    width: 20px;
    height: 20px;
    fill: var(--text-primary);
}

/* Section Title */
.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    text-align: center;
}

/* About */
.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
}

.stat-label {
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
}

.skill-card h3 {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    padding: 0.4rem 0.8rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Experience */
.timeline {
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    border-left: 2px solid var(--border);
    padding-left: 2rem;
    padding-bottom: 2rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 0;
    width: 10px;
    height: 10px;
    background: var(--accent);
    border-radius: 50%;
}

.timeline-date {
    color: var(--accent);
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.timeline-item h3 {
    margin-bottom: 0.25rem;
}

.timeline-company {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.timeline-item ul {
    list-style: none;
    padding: 0;
}

.timeline-item li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
}

.timeline-item li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* Projects */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
}

.project-card h3 {
    margin-bottom: 1rem;
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    padding: 0.3rem 0.7rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Education */
.education-card {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2rem;
}

.education-card h3 {
    margin-bottom: 0.5rem;
}

.education-degree {
    color: var(--accent);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.education-date {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.education-card ul {
    list-style: none;
    padding: 0;
}

.education-card li {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    padding-left: 1.5rem;
    position: relative;
}

.education-card li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* Contact */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 900px;
    margin: 0 auto;
}

.contact-info p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-item svg {
    width: 24px;
    height: 24px;
    fill: var(--accent);
    flex-shrink: 0;
}

.contact-details h4 {
    margin-bottom: 0.25rem;
    font-size: 0.95rem;
}

.contact-details a {
    color: var(--accent);
    text-decoration: none;
}

.contact-details span {
    color: var(--text-secondary);
}

/* Form */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
}

.form-group input,
.form-group textarea {
    padding: 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.contact-form button[type="submit"] {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border: none;
    font-size: 1rem;
    padding: 0.85rem 1.75rem;
    transition: transform 0.2s, box-shadow 0.2s, opacity 0.2s;
}

.contact-form button[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.contact-form button[type="submit"]:active {
    transform: translateY(0);
}

#form-status {
    padding: 0.75rem;
    border-radius: 6px;
    text-align: center;
}

#form-status.success {
    background: #d1fae5;
    color: #065f46;
}

body.dark-mode #form-status.success {
    background: #064e3b;
    color: #6ee7b7;
}

#form-status.error {
    background: #fee2e2;
    color: #991b1b;
}

body.dark-mode #form-status.error {
    background: #7f1d1d;
    color: #fca5a5;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: 2rem;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: transform 0.3s, opacity 0.3s, visibility 0.3s;
        z-index: 99;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .mobile-toggle {
        display: block;
    }

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

    .hero .subtitle {
        font-size: 1.25rem;
    }

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

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