/* ===========================
   GLOBAL STYLES & VARIABLES
   =========================== */

:root {
    /* Colors - bold multi-color gradient theme over a deep navy base */
    --color-bg: #0a0e27;
    --color-bg-secondary: #141a3d;
    --color-bg-tertiary: #1f2757;
    --color-text: #f1f3fb;
    --color-text-secondary: #aab4de;
    --color-text-muted: #7680ab;
    --color-primary: #00d4ff;
    --color-primary-dark: #00a8cc;
    --color-secondary: #ff2e93;
    --color-accent: #8b5cf6;
    --color-gradient-1: #00d4ff;
    --color-gradient-2: #8b5cf6;
    --color-gradient-3: #ff2e93;
    --color-success: #3fe0a5;
    --color-error: #ff4d6d;

    /* Surfaces & borders - translucent so the star field shows through */
    --surface: rgba(31, 39, 87, 0.4);
    --surface-hover: rgba(31, 39, 87, 0.65);
    --border: rgba(0, 212, 255, 0.18);
    --border-hover: rgba(139, 92, 246, 0.55);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;

    /* Typography */
    --font-primary: 'Poppins', sans-serif;
    --font-secondary: 'Inter', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.375rem;
    --font-size-2xl: clamp(1.375rem, 1.15rem + 1vw, 1.75rem);
    --font-size-3xl: clamp(1.75rem, 1.4rem + 1.5vw, 2.5rem);
    --font-size-4xl: clamp(2rem, 1.4rem + 2.6vw, 3.25rem);

    /* Radius */
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-pill: 50px;

    /* Effects - colorful glow shadows */
    --shadow-sm: 0 4px 16px rgba(0, 212, 255, 0.15);
    --shadow-md: 0 12px 32px rgba(139, 92, 246, 0.28);
    --shadow-lg: 0 24px 60px rgba(255, 46, 147, 0.3);

    /* Transitions */
    --transition-fast: 0.18s ease;
    --transition-base: 0.25s ease;
    --transition-slow: 0.55s ease;

    /* Layout */
    --container-width: 1200px;
}

/* ===========================
   RESET & BASE STYLES
   =========================== */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

body {
    font-family: var(--font-secondary);
    background: linear-gradient(160deg, var(--color-bg) 0%, var(--color-bg-secondary) 100%);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: inherit;
}

/* Focus visibility for keyboard users */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
}

/* ===========================
   STAR FIELD BACKGROUND
   =========================== */

#starfield {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
    display: block;
}

/* ===========================
   SCROLL PROGRESS BAR
   =========================== */

.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-gradient-1), var(--color-gradient-2), var(--color-gradient-3));
    width: 0%;
    z-index: 9999;
    box-shadow: 0 0 12px rgba(0, 212, 255, 0.6);
    transition: width 0.1s ease;
}

/* ===========================
   NAVIGATION BAR
   =========================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background: rgba(10, 14, 39, 0.75);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.navbar.scrolled {
    background: rgba(10, 14, 39, 0.92);
    border-bottom-color: var(--border-hover);
    box-shadow: var(--shadow-sm);
}

.navbar-container {
    max-width: var(--container-width);
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-logo a {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    text-decoration: none;
    background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: filter var(--transition-base);
}

.navbar-logo a:hover {
    filter: brightness(1.25);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-base);
    position: relative;
    font-size: var(--font-size-sm);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-gradient-1), var(--color-gradient-2));
    transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
    background: none;
    border: none;
    padding: 8px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 3px;
    transition: var(--transition-base);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(10px, 10px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* ===========================
   HERO SECTION
   =========================== */

.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 100px var(--spacing-lg) var(--spacing-xxl);
    margin-top: 70px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 550px;
    height: 550px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.16) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 9s ease-in-out infinite;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 450px;
    height: 450px;
    background: radial-gradient(circle, rgba(255, 46, 147, 0.14) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 7s ease-in-out infinite reverse;
}

.hero-content {
    max-width: var(--container-width);
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xxl);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text);
    font-family: var(--font-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2), var(--color-gradient-3));
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradient-shift 4s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
}

.hero-subtitle {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--color-primary);
    min-height: 1.6em;
    font-family: var(--font-primary);
}

.typing-text {
    display: inline-block;
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 500px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-pill);
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base), color var(--transition-base);
    font-family: var(--font-primary);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
    color: #050714;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    background: rgba(0, 212, 255, 0.12);
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
}

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

.profile-card {
    width: 280px;
    height: 280px;
    position: relative;
    animation: float-profile 4s ease-in-out infinite;
}

.profile-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.18), rgba(139, 92, 246, 0.18));
    border-radius: var(--radius-lg);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 100px;
    color: var(--color-primary);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(0, 212, 255, 0.3);
    box-shadow: var(--shadow-lg);
}

@keyframes float-profile {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-14px);
    }
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    animation: bounce 2.4s infinite;
}

.scroll-indicator span {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid var(--color-primary);
    border-radius: 13px;
    display: flex;
    justify-content: center;
    padding: 8px 0;
    position: relative;
}

.wheel {
    width: 3px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 2px;
    animation: scroll 1.5s infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    50% {
        transform: translateX(-50%) translateY(8px);
    }
}

@keyframes scroll {
    0% {
        opacity: 1;
        transform: translateY(0);
    }
    100% {
        opacity: 0;
        transform: translateY(12px);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(24px);
    }
}

/* ===========================
   CONTAINER & SECTIONS
   =========================== */

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

section {
    padding: var(--spacing-xxl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xxl);
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-primary);
}

.title-underline {
    width: 70px;
    height: 4px;
    background: linear-gradient(90deg, var(--color-gradient-1), var(--color-gradient-2));
    margin: 0 auto;
    border-radius: 2px;
    box-shadow: var(--shadow-sm);
}

/* ===========================
   ABOUT SECTION
   =========================== */

.about {
    background: rgba(20, 26, 61, 0.45);
    position: relative;
    overflow: hidden;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 320px;
    height: 320px;
    background: radial-gradient(circle, rgba(255, 46, 147, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xxl);
    align-items: start;
    position: relative;
}

.about-bio {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.skills-container {
    position: relative;
}

.skills-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    font-family: var(--font-primary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg) var(--spacing-xl);
}

.skill-category h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-primary);
}

.skill-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(0, 212, 255, 0.08);
    color: var(--color-primary);
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: var(--radius-pill);
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: var(--transition-base);
    cursor: default;
}

.badge:hover {
    background: rgba(0, 212, 255, 0.18);
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

/* ===========================
   PROJECTS SECTION
   =========================== */

.projects {
    background: linear-gradient(180deg, rgba(10, 14, 39, 0.5) 0%, rgba(20, 26, 61, 0.25) 100%);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    backdrop-filter: blur(10px);
    transition: border-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-base), opacity var(--transition-base), background var(--transition-base);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-lg);
    transform: translateY(-8px);
    background: var(--surface-hover);
}

.project-image {
    width: 100%;
    height: 180px;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.12), rgba(139, 92, 246, 0.12));
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.project-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.08) 50%, transparent 70%);
    animation: shine 4s infinite;
}

@keyframes shine {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

.project-placeholder {
    font-size: 56px;
    color: rgba(0, 212, 255, 0.45);
    transition: var(--transition-base);
}

.project-card:hover .project-placeholder {
    color: var(--color-primary);
}

.project-content {
    padding: var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.project-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-primary);
}

.project-description {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
    flex: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tech-tag {
    display: inline-block;
    padding: 3px 10px;
    background: rgba(139, 92, 246, 0.18);
    color: #c4a9ff;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    color: var(--color-primary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: var(--transition-base);
    padding: 5px 10px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(0, 212, 255, 0.3);
}

.project-link:hover {
    background: rgba(0, 212, 255, 0.12);
    border-color: var(--color-primary);
    transform: translateX(3px);
}

/* ===========================
   RESUME SECTION
   =========================== */

.resume {
    background: rgba(20, 26, 61, 0.3);
}

.resume-content {
    text-align: center;
}

.resume-intro {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
    line-height: 1.8;
}

.experience-preview {
    max-width: 800px;
    margin: var(--spacing-xxl) auto 0;
    text-align: left;
}

.preview-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    font-family: var(--font-primary);
}

.timeline {
    position: relative;
    padding-left: 30px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--color-gradient-1), var(--color-gradient-2), var(--color-gradient-3));
}

.timeline-item {
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.timeline-marker {
    position: absolute;
    left: -37px;
    top: 5px;
    width: 14px;
    height: 14px;
    background: var(--color-primary);
    border: 2px solid var(--color-bg);
    border-radius: 50%;
    box-shadow: 0 0 12px rgba(0, 212, 255, 0.6);
}

.timeline-content h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 3px;
    font-family: var(--font-primary);
}

.timeline-date {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.timeline-content p {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

/* ===========================
   CONTACT SECTION
   =========================== */

.contact {
    background: rgba(31, 39, 87, 0.25);
    position: relative;
    overflow: hidden;
}

.contact::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -10%;
    width: 420px;
    height: 420px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xxl);
    align-items: start;
    position: relative;
}

.contact-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-primary);
}

.contact-description {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.contact-item > div {
    min-width: 0;
}

.contact-item a,
.contact-item p {
    overflow-wrap: break-word;
    word-break: break-word;
}

.contact-item i {
    font-size: var(--font-size-xl);
    color: var(--color-primary);
    margin-top: 3px;
}

.contact-item h4 {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 5px;
    font-family: var(--font-primary);
}

.contact-item a {
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: var(--transition-base);
}

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

.contact-item p {
    color: var(--color-text-secondary);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.social-icon {
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(0, 212, 255, 0.08);
    border: 2px solid rgba(0, 212, 255, 0.3);
    border-radius: 50%;
    color: var(--color-primary);
    transition: var(--transition-base);
    font-size: var(--font-size-lg);
}

.social-icon:hover {
    background: var(--color-primary);
    color: var(--color-bg);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.contact-form {
    background: var(--surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-group label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-text);
    font-family: var(--font-primary);
}

.form-group input,
.form-group textarea {
    padding: var(--spacing-md);
    background: rgba(10, 14, 39, 0.7);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-family: var(--font-secondary);
    font-size: var(--font-size-base);
    transition: var(--transition-base);
    resize: none;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.2);
    transform: scale(1.01);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-muted);
}

/* ===========================
   FOOTER
   =========================== */

.footer {
    background: rgba(10, 14, 39, 0.7);
    border-top: 1px solid var(--border);
    padding: var(--spacing-lg) 0;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-content p {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.footer-content i {
    color: var(--color-secondary);
    animation: heartbeat 1.2s ease infinite;
}

@keyframes heartbeat {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

/* ===========================
   BACK TO TOP BUTTON
   =========================== */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
    color: var(--color-bg);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    justify-content: center;
    align-items: center;
    font-size: var(--font-size-lg);
    z-index: 999;
    transition: var(--transition-base);
    box-shadow: var(--shadow-md);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.back-to-top.show {
    display: flex;
    animation: slideUp 0.3s ease;
}

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

/* ===========================
   ACTIVITIES SECTION
   =========================== */

.activities {
    background: rgba(31, 39, 87, 0.25);
    position: relative;
    overflow: hidden;
}

.activities::after {
    content: '';
    position: absolute;
    bottom: -30%;
    right: -10%;
    width: 420px;
    height: 420px;
    background: radial-gradient(circle, rgba(255, 46, 147, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.activity-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    backdrop-filter: blur(10px);
    position: relative;
    z-index: 1;
    transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

.activity-card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-lg);
    transform: translateY(-8px);
    background: var(--surface-hover);
}

.activity-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.18), rgba(139, 92, 246, 0.18));
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 auto var(--spacing-lg);
    font-size: 34px;
    color: var(--color-primary);
    border: 1px solid rgba(0, 212, 255, 0.3);
    transition: var(--transition-base);
}

.activity-card:hover .activity-icon {
    transform: scale(1.08);
    border-color: var(--color-primary);
}

.activity-card h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
    font-family: var(--font-primary);
}

.activity-role {
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-md);
    display: block;
}

.activity-description {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    line-height: 1.6;
}

/* ===========================
   RESPONSIVE DESIGN
   =========================== */

@media (max-width: 768px) {
    :root {
        --spacing-xxl: 2.5rem;
        --spacing-xl: 1.5rem;
    }

    .navbar-container {
        padding: 0 var(--spacing-md);
    }

    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: rgba(10, 14, 39, 0.97);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: var(--spacing-lg) 0;
        gap: var(--spacing-md);
        border-bottom: 1px solid var(--border);
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .hero-buttons {
        flex-direction: column;
    }

    .btn, .btn-large {
        width: 100%;
    }

    .profile-card {
        width: 200px;
        height: 200px;
    }

    .profile-placeholder {
        font-size: 70px;
    }

    .hero::before, .hero::after {
        display: none;
    }

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

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

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

    .contact-form {
        padding: var(--spacing-lg);
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-lg: 1rem;
        --spacing-md: 0.75rem;
    }

    .navbar-container {
        padding: 0 var(--spacing-sm);
    }

    .navbar-logo a {
        font-size: var(--font-size-lg);
    }

    .hero {
        padding: 80px var(--spacing-md) var(--spacing-lg);
    }

    .profile-card {
        width: 150px;
        height: 150px;
    }

    .profile-placeholder {
        font-size: 50px;
    }

    .about-bio {
        font-size: var(--font-size-base);
    }

    .skill-badges {
        gap: 5px;
    }

    .badge {
        padding: 4px 8px;
        font-size: var(--font-size-xs);
    }

    .project-card {
        border-radius: var(--radius-md);
    }

    .project-image {
        height: 150px;
    }

    .project-placeholder {
        font-size: 40px;
    }

    .contact-details {
        gap: var(--spacing-md);
    }

    .social-links {
        gap: var(--spacing-sm);
    }

    .social-icon {
        width: 42px;
        height: 42px;
        font-size: var(--font-size-base);
    }

    .footer-content p {
        font-size: var(--font-size-xs);
    }
}

/* ===========================
   ANIMATIONS
   =========================== */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn var(--transition-slow) ease forwards;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ===========================
   REDUCED MOTION
   =========================== */

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
    }

    .scroll-indicator,
    .wheel {
        animation: none !important;
    }
}