/* --- Variables & Color System --- */
:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-blue: #38bdf8;
    --accent-blue-hover: #0284c7;
    --accent-green: #10b981;
    --border-color: #334155;
    --error-color: #ef4444;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-card: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-blue: #0284c7;
    --accent-blue-hover: #0369a1;
    --accent-green: #059669;
    --border-color: #cbd5e1;
}

/* --- Global Resets & Scrollbar --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-blue);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: 5rem 0;
}

.section-alt {
    background-color: var(--bg-secondary);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2.5rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 40%;
    height: 3px;
    background-color: var(--accent-blue);
    border-radius: 2px;
}

/* --- Navbar --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(8px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

[data-theme="light"] .navbar {
    background-color: rgba(248, 250, 252, 0.85);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

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

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-item {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

/* --- Hero --- */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.25rem 0.75rem;
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--accent-green);
    color: var(--accent-green);
    border-radius: 20px;
    font-size: 0.85rem;
    margin-bottom: 1.5rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: var(--accent-green);
    border-radius: 50%;
    box-shadow: 0 0 8px var(--accent-green);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.75rem;
    color: var(--accent-blue);
    margin-bottom: 1rem;
    font-weight: 600;
}

.hero-description {
    max-width: 600px;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--accent-blue);
    color: #0f172a;
}

.btn-primary:hover {
    background-color: var(--accent-blue-hover);
    color: #ffffff;
}

.btn-outlined {
    border-color: var(--border-color);
    color: var(--text-primary);
}

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

.social-links {
    display: flex;
    gap: 1.25rem;
}

.social-links a {
    color: var(--text-secondary);
    font-size: 1.5rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--accent-blue);
    transform: translateY(-2px);
}

/* --- About & Stats --- */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

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

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.stat-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
}

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

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* --- Skills --- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

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

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

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

.badge {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 0.35rem 0.75rem;
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* --- Projects --- */
.filter-bar {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.filter-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--accent-blue);
    color: #0f172a;
    border-color: var(--accent-blue);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

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

.project-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-blue);
    box-shadow: 0 10px 20px -10px rgba(56, 189, 248, 0.15);
}

.project-title {
    margin-bottom: 0.5rem;
}

.project-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.25rem;
}

.tag {
    font-size: 0.75rem;
    color: var(--accent-blue);
    background-color: rgba(56, 189, 248, 0.1);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
}

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

/* --- Timeline --- */
.timeline {
    border-left: 2px solid var(--border-color);
    margin-left: 0.5rem;
    padding-left: 1.5rem;
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-dot {
    position: absolute;
    left: -1.9rem;
    top: 5px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--accent-blue);
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--accent-blue);
}

.timeline-company {
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.timeline-content ul {
    list-style-position: inside;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* --- Contact Section --- */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.contact-card i {
    font-size: 1.25rem;
    color: var(--accent-blue);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

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

.form-group input, .form-group textarea {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.75rem;
    border-radius: 6px;
    outline: none;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus, .form-group textarea:focus {
    border-color: var(--accent-blue);
}

.error-msg {
    color: var(--error-color);
    font-size: 0.75rem;
    display: none;
    margin-top: 0.25rem;
}

.invalid input, .invalid textarea {
    border-color: var(--error-color);
}

.invalid .error-msg {
    display: block;
}

.form-feedback {
    margin-top: 0.5rem;
    font-size: 0.9rem;
    display: none;
}

.form-feedback.success {
    display: block;
    color: var(--accent-green);
}

/* --- Footer --- */
.footer {
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.back-to-top {
    color: var(--text-primary);
    text-decoration: none;
}

/* --- Mobile Responsiveness --- */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }
    .nav-links {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background-color: var(--bg-primary);
        flex-direction: column;
        justify-content: center;
        transition: var(--transition);
    }
    .nav-links.active {
        right: 0;
    }
    .hero-title {
        font-size: 2.5rem;
    }
    .about-grid, .contact-grid {
        grid-template-columns: 1fr;
    }
}