:root {
    /* Dark Theme (Default) */
    --bg-color: #0f172a;
    --text-color: #e2e8f0;
    --accent-color: #38bdf8;
    --secondary-bg: #1e293b;
    --card-bg: rgba(30, 41, 59, 0.7);
    --glass-border: 1px solid rgba(255, 255, 255, 0.1);
    --font-main: 'Inter', sans-serif;
    --transition: all 0.3s ease;
}

[data-theme="light"] {
    --bg-color: #f8fafc;
    --text-color: #1e293b;
    --accent-color: #0284c7;
    --secondary-bg: #e2e8f0;
    --card-bg: rgba(255, 255, 255, 0.7);
    --glass-border: 1px solid rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
}

h2 {
    font-size: 2.5rem;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 3rem;
    text-align: center;
}

h3 {
    font-size: 1.75rem;
}

.text-accent {
    color: var(--accent-color);
}

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

section {
    padding: 5rem 0;
}

/* Header */
header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: var(--glass-border);
    transition: background 0.3s ease;
}

[data-theme="light"] header {
    background: rgba(248, 250, 252, 0.8);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

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

/* Theme Toggle */
#theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
}

#theme-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--accent-color);
}

[data-theme="light"] #theme-toggle:hover {
    background: rgba(0, 0, 0, 0.05);
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

.hero-content h1 {
    margin-bottom: 1rem;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

[data-theme="light"] .hero-content h1 {
    background: linear-gradient(to right, #1e293b, #64748b);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-content p {
    font-size: 1.25rem;
    color: #94a3b8;
    margin-bottom: 2rem;
}

[data-theme="light"] .hero-content p {
    color: #475569;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    background: var(--accent-color);
    color: #fff;
    border-radius: 50px;
    font-weight: 600;
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(56, 189, 248, 0.2);
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-img {
    width: 100%;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.skill-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 15px;
    border: var(--glass-border);
    text-align: center;
    transition: var(--transition);
}

.skill-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
}

.skill-icon {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

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

.timeline-item {
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 15px;
    border: var(--glass-border);
    margin-bottom: 2rem;
    position: relative;
}

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

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

.project-card {
    background: var(--card-bg);
    border-radius: 15px;
    overflow: hidden;
    border: var(--glass-border);
    transition: var(--transition);
}

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

.project-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.project-info {
    padding: 1.5rem;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.tag {
    font-size: 0.8rem;
    padding: 0.2rem 0.8rem;
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-color);
    border-radius: 20px;
}

/* Contact */
.contact-container {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

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

.social-icon {
    font-size: 2rem;
    color: var(--text-color);
}

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

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0;
    color: #94a3b8;
    border-top: var(--glass-border);
    margin-top: 4rem;
}

[data-theme="light"] footer {
    color: #64748b;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 2.2rem;
    }

    .hero-content h1 {
        font-size: 2.5rem;
        margin-bottom: 0.5rem;
    }

    .hero-content .role-description {
        font-size: 0.8rem;
        margin-bottom: 1rem;
        padding: 0 0.5rem;
        white-space: nowrap;
    }

    .hero-content .tagline {
        font-size: 0.9rem;
        padding: 0 1rem;
    }

    .mobile-menu-btn {
        display: block;
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: var(--bg-color);
        flex-direction: column;
        padding: 2rem;
        border-bottom: var(--glass-border);
        transform: translateY(-150%);
        transition: transform 0.3s ease;
    }

    .nav-links.active {
        transform: translateY(0);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    }

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