/* ===========================
   Apple-inspired Design System
   =========================== */

:root {
    --primary-color: #000;
    --secondary-color: #f5f5f7;
    --text-primary: #1d1d1d;
    --text-secondary: #6f6f77;
    --accent-color: #0071e3;
    --accent-light: #f0f0f0;
    --border-color: #e5e5e7;
    --white: #ffffff;
    --spacing-unit: 1rem;
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', sans-serif;
    color: var(--text-primary);
    line-height: 1.6;
    background-color: var(--white);
    font-size: 16px;
    font-weight: 400;
    letter-spacing: -0.3px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===========================
   Navigation
   =========================== */

.navbar {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.5rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
    letter-spacing: -0.2px;
}

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

.nav-link.active {
    color: var(--accent-color);
}

.nav-link::after {
    display: none;
}

/* ===========================
   Hero Section
   =========================== */

.hero {
    background-color: var(--white);
    padding: 140px 20px;
    text-align: center;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-content {
    max-width: 900px;
}

.hero-title {
    font-size: 5.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    animation: fadeInUp 0.8s ease-out;
    letter-spacing: -1px;
    line-height: 1.05;
}

.hero-subtitle {
    font-size: 2rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    animation: fadeInUp 0.8s ease-out 0.1s both;
    letter-spacing: -0.5px;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 3rem;
    color: var(--text-secondary);
    animation: fadeInUp 0.8s ease-out 0.2s both;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-button {
    display: inline-block;
    padding: 12px 28px;
    background-color: var(--accent-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 980px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
    animation: fadeInUp 0.8s ease-out 0.3s both;
    border: none;
    cursor: pointer;
    letter-spacing: -0.2px;
}

.cta-button:hover {
    background-color: #0077ed;
    transform: scale(1.02);
    box-shadow: 0 8px 20px rgba(0, 113, 227, 0.3);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===========================
   Section Styles
   =========================== */

section {
    padding: 100px 20px;
}

.section-title {
    font-size: 3.5rem;
    margin-bottom: 4rem;
    text-align: center;
    color: var(--text-primary);
    position: relative;
    font-weight: 700;
    letter-spacing: -0.8px;
    line-height: 1.1;
}

.section-title::after {
    display: none;
}

/* ===========================
   About Section
   =========================== */

.about {
    background-color: var(--white);
}

.about-content {
    max-width: 850px;
    margin: 0 auto;
    line-height: 1.8;
    font-size: 1.05rem;
    color: var(--text-secondary);
}

.about-content p {
    margin-bottom: 2rem;
    letter-spacing: -0.3px;
}

.skills {
    margin-top: 3rem;
}

.skills h3 {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    font-weight: 600;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
}

.skill-tag {
    background-color: var(--accent-light);
    color: var(--text-primary);
    padding: 12px 16px;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
    font-size: 0.95rem;
    border: 1px solid var(--border-color);
    letter-spacing: -0.2px;
}

.skill-tag:hover {
    background-color: var(--accent-color);
    color: var(--white);
    border-color: var(--accent-color);
    transform: translateY(-2px);
}

/* ===========================
   Experience Section
   =========================== */

.experience {
    background-color: var(--secondary-color);
}

.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 100%;
    background-color: var(--border-color);
}

.timeline-item {
    margin-bottom: 4rem;
    position: relative;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-left: 0;
    margin-right: auto;
    padding-right: 50px;
    width: 48%;
    text-align: right;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: auto;
    margin-right: 0;
    padding-left: 50px;
    width: 48%;
    text-align: left;
}

.timeline-marker {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 12px;
    height: 12px;
    background-color: var(--accent-color);
    border-radius: 50%;
    border: 3px solid var(--white);
    box-shadow: 0 0 0 1px var(--border-color);
    top: 0;
    transition: var(--transition);
}

.timeline-item:hover .timeline-marker {
    width: 16px;
    height: 16px;
    transform: translateX(-50%) scale(1.2);
}

.timeline-content h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.timeline-content .company {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.timeline-content .date {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.timeline-content .description {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
    letter-spacing: -0.2px;
}

/* Responsive timeline */
@media (max-width: 768px) {
    .timeline::before {
        left: 0;
    }

    .timeline-marker {
        left: 0;
    }

    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        width: 100%;
        padding-left: 50px;
        padding-right: 0;
        text-align: left;
    }
}

/* ===========================
   Projects Section
   =========================== */

.projects {
    background-color: var(--white);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

.project-card {
    background-color: var(--secondary-color);
    padding: 2.5rem;
    border-radius: 18px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    text-align: center;
}

.project-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-color);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.project-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: inline-block;
}

.project-card h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
    letter-spacing: -0.2px;
}

/* ===========================
   Education Section
   =========================== */

.education {
    background-color: var(--secondary-color);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

.education-card {
    background-color: var(--white);
    padding: 2.5rem;
    border-radius: 18px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.education-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-color);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.education-card h3 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.education-card .institution {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.education-card .graduation {
    display: none;
}

.education-card .details {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 0.95rem;
    letter-spacing: -0.2px;
}

/* ===========================
   Contact Section
   =========================== */

.contact {
    background: linear-gradient(135deg, var(--primary-color) 0%, #1d1d1d 100%);
    color: var(--white);
}

.contact .section-title {
    color: var(--white);
}

.contact .section-title::after {
    display: none;
}

.contact-intro {
    text-align: center;
    font-size: 1.05rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    color: rgba(255, 255, 255, 0.8);
    letter-spacing: -0.2px;
}

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

.contact-info {
    display: grid;
    gap: 2rem;
}

.contact-item h4 {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    letter-spacing: -0.2px;
}

.contact-item p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.contact-item a {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    transition: var(--transition);
    letter-spacing: -0.2px;
}

.contact-item a:hover {
    color: var(--accent-color);
}

.social-links h4 {
    font-size: 0.95rem;
    margin-bottom: 1rem;
    font-weight: 600;
    letter-spacing: -0.2px;
}

.social-icons {
    display: flex;
    gap: 1rem;
}

.social-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--white);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.social-icon:hover {
    background-color: rgba(255, 255, 255, 0.2);
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

/* ===========================
   Footer
   =========================== */

.footer {
    background-color: var(--secondary-color);
    color: var(--text-secondary);
    text-align: center;
    padding: 2.5rem 20px;
    border-top: 1px solid var(--border-color);
}

.footer p {
    margin: 0;
    font-size: 0.9rem;
    letter-spacing: -0.2px;
}

@media (max-width: 768px) {
    .hero {
        padding: 80px 20px;
        min-height: auto;
    }

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

    .hero-subtitle {
        font-size: 1.3rem;
        margin-bottom: 0.8rem;
    }

    .hero-description {
        font-size: 1rem;
        margin-bottom: 2rem;
    }

    .section-title {
        font-size: 2.5rem;
        margin-bottom: 2.5rem;
    }

    .nav-menu {
        gap: 1.5rem;
        font-size: 0.85rem;
    }

    .about-content {
        font-size: 1rem;
    }

    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    section {
        padding: 60px 20px;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        width: 100%;
        padding-left: 40px;
        padding-right: 0;
        text-align: left;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .cta-button {
        padding: 10px 24px;
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .nav-menu {
        gap: 0.8rem;
        font-size: 0.75rem;
    }

    .logo {
        font-size: 0.95rem;
    }

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

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

    section {
        padding: 50px 20px;
    }
}