/* ============================================
   Design System: cassius-portfolio v2
   Style: Motion-Driven + Bold
   Colors: Black + Royal Blue
   Typography: Archivo / Space Grotesk / JetBrains Mono
   ============================================ */

:root {
    /* Core Palette — Black + Royal Blue */
    --black: #000000;
    --white: #FFFFFF;
    --royal: #1B3FA0;
    --royal-bright: #2952D4;
    --royal-light: #3B63E0;
    --royal-glow: #4A75F0;
    --blue-accent: #5B8AFB;
    --surface: #0A0A0A;
    --surface-1: #111111;
    --surface-2: #1A1A1A;
    --surface-3: #222222;
    --gray-100: #F5F5F5;
    --gray-200: #E5E5E5;
    --gray-400: #A3A3A3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;

    --font-heading: 'Archivo', sans-serif;
    --font-body: 'Space Grotesk', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 4rem;
    --space-2xl: 6rem;
    --space-3xl: 8rem;

    --duration-fast: 150ms;
    --duration-normal: 300ms;
    --duration-slow: 600ms;
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 5rem; }

body {
    font-family: var(--font-body);
    color: var(--gray-200);
    background: var(--surface);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

::selection {
    background: var(--royal);
    color: var(--white);
}

/* ===== CURSOR GLOW ===== */
.cursor-glow {
    position: fixed;
    width: 700px;
    height: 700px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(27, 63, 160, 0.12) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
    transform: translate(-50%, -50%);
    transition: opacity 0.3s;
}

/* ===== PARTICLE CANVAS ===== */
#particleCanvas {
    position: absolute;
    inset: 0;
    z-index: 0;
    pointer-events: none;
}

/* ===== NAV ===== */
.navbar {
    position: fixed; top: 0; width: 100%; z-index: 1000;
    background: rgba(10, 10, 10, 0.7);
    backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: all var(--duration-normal) var(--ease-out);
}
.navbar.scrolled { border-bottom-color: var(--surface-2); background: rgba(10, 10, 10, 0.95); }

.nav-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 1rem 2rem; }
.nav-logo { font-family: var(--font-heading); font-size: 1.5rem; font-weight: 800; color: var(--white); text-decoration: none; letter-spacing: -0.02em; }
.logo-dot { color: var(--royal-bright); }

.menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 4px; z-index: 1001; }
.menu-toggle span { width: 24px; height: 2px; background: var(--white); transition: all var(--duration-normal) var(--ease-out); transform-origin: center; }
.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.nav-menu { display: flex; gap: 2rem; list-style: none; }
.nav-menu a { color: var(--gray-500); text-decoration: none; font-weight: 500; font-size: 0.9rem; letter-spacing: 0.02em; transition: color var(--duration-fast) var(--ease-out); position: relative; }
.nav-menu a::after { content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px; background: var(--royal-bright); transition: width var(--duration-normal) var(--ease-out); }
.nav-menu a:hover { color: var(--white); }
.nav-menu a:hover::after { width: 100%; }

/* ===== HERO ===== */
.hero {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    text-align: center; padding: 6rem 2rem 2rem; position: relative; overflow: hidden;
    background: var(--surface);
}
.hero-bg-grid {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(27, 63, 160, 0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(27, 63, 160, 0.06) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, black 20%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, black 20%, transparent 100%);
}
.hero-content { position: relative; z-index: 1; max-width: 900px; }

.hero-tag {
    display: inline-block; font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.15em;
    text-transform: uppercase; color: var(--royal-bright); background: rgba(27, 63, 160, 0.15);
    padding: 0.5rem 1.5rem; border-radius: 100px; border: 1px solid rgba(27, 63, 160, 0.3);
    margin-bottom: 2rem;
}
.hero-title { font-family: var(--font-heading); font-size: clamp(3rem, 8vw, 6.5rem); font-weight: 900; line-height: 1.02; letter-spacing: -0.04em; margin-bottom: 1.5rem; color: var(--white); }
.title-line { display: block; }
.title-line.accent {
    background: linear-gradient(135deg, var(--royal-bright) 0%, var(--blue-accent) 50%, #8B5CF6 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-subtitle { font-size: clamp(1rem, 2vw, 1.2rem); color: var(--gray-400); margin-bottom: 1.5rem; line-height: 1.6; }
.highlight { color: var(--royal-bright); font-weight: 600; }

.hero-bio {
    max-width: 700px; margin: 0 auto 2rem; font-size: 0.9rem; color: var(--gray-500);
    line-height: 1.8; text-align: left;
}
.hero-meta { display: flex; gap: 1.5rem; justify-content: center; flex-wrap: wrap; margin-bottom: 2.5rem; }
.meta-item { display: inline-flex; align-items: center; gap: 0.5rem; font-size: 0.85rem; color: var(--gray-400); font-weight: 500; }
.meta-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--royal-bright); display: inline-block; }

.hero-cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.hero-scroll-indicator { position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%); }
.scroll-line { width: 1px; height: 60px; background: linear-gradient(to bottom, var(--royal-bright), transparent); animation: scrollPulse 2s ease-in-out infinite; }
@keyframes scrollPulse { 0%, 100% { opacity: 0.3; } 50% { opacity: 1; } }

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.75rem 1.75rem;
    border-radius: 100px; text-decoration: none; font-weight: 600; font-size: 0.9rem;
    transition: all var(--duration-normal) var(--ease-out); cursor: pointer; border: none;
    font-family: var(--font-body);
}
.btn-primary { background: var(--royal-bright); color: var(--white); }
.btn-primary:hover { background: var(--royal-light); transform: translateY(-2px); box-shadow: 0 8px 32px rgba(27, 63, 160, 0.5); }
.btn-outline { background: transparent; color: var(--gray-200); border: 1.5px solid var(--gray-700); }
.btn-outline:hover { border-color: var(--royal-bright); color: var(--white); transform: translateY(-2px); }
.btn-icon { width: 18px; height: 18px; flex-shrink: 0; }

/* ===== SECTIONS ===== */
.section { padding: var(--space-3xl) 0; }
.section-alt { background: var(--surface-1); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 2rem; }
.section-header { margin-bottom: var(--space-xl); }
.section-number { font-family: var(--font-mono); font-size: 0.75rem; color: var(--royal-bright); letter-spacing: 0.15em; display: block; margin-bottom: 0.5rem; }
.section-title { font-family: var(--font-heading); font-size: clamp(2rem, 4vw, 3.5rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.1; color: var(--white); }

/* ===== ABOUT ===== */
.about-grid { display: grid; grid-template-columns: 1.5fr 1fr; gap: var(--space-xl); align-items: start; }
.about-lead { font-size: 1.15rem; line-height: 1.7; margin-bottom: 1rem; color: var(--gray-200); }
.about-text p { color: var(--gray-400); margin-bottom: 1rem; line-height: 1.8; }
.about-text strong { color: var(--royal-bright); }
.about-text em { color: var(--blue-accent); font-style: normal; font-weight: 500; }

.about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.stat-card {
    background: var(--surface-1); border: 1px solid var(--surface-3); border-radius: var(--radius-md);
    padding: 1.5rem; transition: all var(--duration-normal) var(--ease-out);
}
.stat-card:hover { border-color: var(--royal); transform: translateY(-2px); box-shadow: 0 8px 32px rgba(27, 63, 160, 0.15); }
.stat-number { display: block; font-family: var(--font-heading); font-size: 2.8rem; font-weight: 900; color: var(--royal-bright); line-height: 1; margin-bottom: 0.25rem; }
.stat-label { display: block; font-weight: 600; font-size: 0.85rem; color: var(--gray-200); margin-bottom: 0.25rem; }
.stat-detail { display: block; font-size: 0.7rem; color: var(--gray-500); font-family: var(--font-mono); }

/* ===== EXPERIENCE TIMELINE ===== */
.exp-timeline { position: relative; padding-left: 2rem; }
.exp-timeline::before { content: ''; position: absolute; left: 7px; top: 0; bottom: 0; width: 2px; background: linear-gradient(to bottom, var(--royal-bright), var(--surface-3)); }

.exp-item { position: relative; padding-bottom: var(--space-xl); padding-left: 2.5rem; }
.exp-item:last-child { padding-bottom: 0; }
.exp-marker { position: absolute; left: -2.5rem; top: 8px; width: 16px; height: 16px; border-radius: 50%; background: var(--surface-1); border: 3px solid var(--surface-3); z-index: 1; transition: all var(--duration-normal) var(--ease-out); }
.exp-marker.active { background: var(--royal-bright); border-color: var(--royal-bright); box-shadow: 0 0 0 4px rgba(27, 63, 160, 0.25); }
.exp-marker.active::after { content: ''; position: absolute; inset: -6px; border-radius: 50%; border: 2px solid rgba(27, 63, 160, 0.3); animation: pulse 2s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: 0; transform: scale(1); } 50% { opacity: 1; transform: scale(1.2); } }

.exp-period { font-family: var(--font-mono); font-size: 0.75rem; color: var(--royal-bright); letter-spacing: 0.05em; margin-bottom: 0.25rem; }
.exp-content { background: var(--surface-2); border: 1px solid var(--surface-3); border-radius: var(--radius-md); padding: 1.5rem; transition: all var(--duration-normal) var(--ease-out); }
.exp-content:hover { border-color: var(--royal); transform: translateY(-2px); }
.exp-header { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; margin-bottom: 0.25rem; }
.exp-logo-wrap { width: 36px; height: 36px; border-radius: 6px; overflow: hidden; flex-shrink: 0; display: flex; align-items: center; justify-content: center; background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.08); }
.exp-logo { width: 28px; height: 28px; object-fit: contain; }
.exp-logo-wrap svg.exp-logo { width: 100%; height: 100%; }
.exp-header h3 { font-family: var(--font-heading); font-size: 1.1rem; font-weight: 600; color: var(--white); letter-spacing: -0.01em; }
.exp-org { font-size: 0.8rem; color: var(--gray-500); margin-bottom: 0.5rem; }
.exp-content p { color: var(--gray-400); font-size: 0.9rem; line-height: 1.7; }
.exp-skills { display: flex; flex-wrap: wrap; gap: 0.35rem; margin-top: 0.75rem; }
.exp-skills span { font-size: 0.7rem; padding: 0.2rem 0.6rem; border-radius: 100px; background: rgba(27, 63, 160, 0.15); color: var(--royal-glow); border: 1px solid rgba(27, 63, 160, 0.2); font-weight: 500; }

.exp-tag { display: inline-block; padding: 0.2rem 0.65rem; border-radius: 100px; font-size: 0.65rem; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; }
.tag-finep { background: rgba(245, 158, 11, 0.15); color: #F59E0B; border: 1px solid rgba(245, 158, 11, 0.3); }
.tag-cnpq { background: rgba(59, 130, 246, 0.15); color: #60A5FA; border: 1px solid rgba(59, 130, 246, 0.3); }
.tag-lse { background: rgba(34, 197, 94, 0.15); color: #4ADE80; border: 1px solid rgba(34, 197, 94, 0.3); }
.tag-lsa { background: rgba(249, 115, 22, 0.15); color: #FB923C; border: 1px solid rgba(249, 115, 22, 0.3); }
.tag-vhlab { background: rgba(168, 85, 247, 0.15); color: #C084FC; border: 1px solid rgba(168, 85, 247, 0.3); }

/* ===== RESEARCH CARDS ===== */
.research-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }

.research-card {
    background: var(--surface-1); border: 1px solid var(--surface-3); border-radius: var(--radius-lg);
    padding: 2rem 2.5rem; transition: all var(--duration-normal) var(--ease-out); position: relative; overflow: hidden;
}
.research-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: linear-gradient(90deg, var(--royal-bright), #8B5CF6); opacity: 0; transition: opacity var(--duration-normal) var(--ease-out); }
.research-card:hover { transform: translateY(-3px); box-shadow: 0 20px 60px rgba(27, 63, 160, 0.18); border-color: var(--royal); }
.research-card:hover::before { opacity: 1; }

.research-card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.25rem; }

.agency-badge { display: flex; align-items: center; gap: 0.75rem; }
.agency-logo { height: 20px; width: auto; display: block; }

.project-code {
    font-family: var(--font-mono); font-size: 0.68rem; color: var(--gray-400);
    background: var(--surface-3); border: 1px solid rgba(255,255,255,0.06);
    padding: 0.2rem 0.65rem; border-radius: var(--radius-sm); letter-spacing: 0.05em;
}

.research-status { font-size: 0.68rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; padding: 0.3rem 0.9rem; border-radius: 100px; background: var(--surface-2); color: var(--gray-500); display: inline-block; border: 1px solid var(--surface-3); flex-shrink: 0; }
.research-status.active { background: rgba(34, 197, 94, 0.08); color: #4ADE80; border-color: rgba(34, 197, 94, 0.2); }

.research-number-bg { font-family: var(--font-heading); font-size: 5rem; font-weight: 900; color: rgba(27, 63, 160, 0.07); line-height: 1; margin-bottom: 0.25rem; letter-spacing: -0.05em; }
.research-card h3 { font-family: var(--font-heading); font-size: 1.6rem; font-weight: 800; color: var(--white); margin-bottom: 0.4rem; letter-spacing: -0.02em; }
.research-subtitle { font-size: 0.875rem; color: var(--gray-500); margin-bottom: 1.25rem; line-height: 1.5; font-style: italic; }

.research-meta-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 0.75rem 2rem; margin-bottom: 1.25rem; padding: 1rem 1.25rem; background: rgba(0,0,0,0.25); border-radius: var(--radius-md); border: 1px solid rgba(255,255,255,0.04); }
.research-meta-item { display: flex; flex-direction: column; gap: 0.15rem; }
.meta-key { font-family: var(--font-mono); font-size: 0.62rem; color: var(--royal-bright); text-transform: uppercase; letter-spacing: 0.12em; font-weight: 600; }
.meta-val { font-size: 0.8rem; color: var(--gray-300); line-height: 1.4; }

.research-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1rem; }
.research-description { color: var(--gray-400); font-size: 0.9rem; line-height: 1.7; }

/* ===== SKILLS ===== */
.skills-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }
.skill-group { background: var(--surface-1); border: 1px solid var(--surface-3); border-radius: var(--radius-md); padding: 1.5rem; }
.skill-group h3 { font-family: var(--font-heading); font-size: 0.85rem; font-weight: 700; color: var(--royal-bright); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 1rem; }
.skill-items { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.skill-items span { font-size: 0.8rem; padding: 0.35rem 0.85rem; border-radius: 100px; background: var(--surface-2); color: var(--gray-300); border: 1px solid var(--surface-3); font-weight: 500; transition: all var(--duration-fast) var(--ease-out); }
.skill-items span:hover { border-color: var(--royal); color: var(--white); transform: translateY(-1px); }
.interest-items span { background: rgba(27, 63, 160, 0.1) !important; color: var(--royal-glow) !important; border-color: rgba(27, 63, 160, 0.2) !important; }
.interest-items span:hover { background: var(--royal-bright) !important; color: var(--white) !important; }

/* Education */
.education-section { margin-top: var(--space-xl); }
.education-section h3 { font-family: var(--font-heading); font-size: 0.85rem; font-weight: 700; color: var(--royal-bright); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 1rem; }
.edu-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1rem; }
.edu-card { background: var(--surface-1); border: 1px solid var(--surface-3); border-radius: var(--radius-md); padding: 1.5rem; transition: all var(--duration-normal) var(--ease-out); }
.edu-card:hover { border-color: var(--royal); }
.edu-degree { font-weight: 600; color: var(--white); font-size: 0.95rem; margin-bottom: 0.25rem; }
.edu-school { font-size: 0.85rem; color: var(--gray-400); margin-bottom: 0.25rem; }
.edu-period { font-size: 0.75rem; color: var(--gray-500); font-family: var(--font-mono); }

/* Publications */
.publications-section { margin-top: var(--space-xl); }
.publications-section h3 { font-family: var(--font-heading); font-size: 0.85rem; font-weight: 700; color: var(--royal-bright); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 1rem; }
.pub-card { background: var(--surface-1); border: 1px solid var(--surface-3); border-radius: var(--radius-md); padding: 1.5rem; border-left: 3px solid var(--royal-bright); }
.pub-title { font-size: 0.95rem; color: var(--gray-200); line-height: 1.5; font-style: italic; }
.pub-meta { font-size: 0.75rem; color: var(--gray-500); margin-top: 0.5rem; font-family: var(--font-mono); }

/* ===== CONTACT ===== */
.contact-grid { max-width: 600px; }
.contact-info { display: flex; flex-direction: column; gap: 1.25rem; }
.contact-item { display: flex; align-items: center; gap: 1rem; font-size: 0.95rem; color: var(--gray-300); text-decoration: none; transition: color var(--duration-fast); }
.contact-item:hover { color: var(--royal-bright); }
.contact-item svg { width: 20px; height: 20px; stroke: var(--royal-bright); flex-shrink: 0; }

/* ===== FOOTER ===== */
.footer { background: var(--black); color: var(--gray-400); padding: var(--space-xl) 0; border-top: 1px solid var(--surface-3); }
.footer .container { display: flex; flex-direction: column; align-items: center; gap: 1rem; }
.footer-name { font-family: var(--font-heading); font-size: 1.1rem; font-weight: 700; color: var(--white); }
.footer-subtitle { font-size: 0.85rem; color: var(--gray-500); }
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { color: var(--gray-600); transition: color var(--duration-fast); }
.footer-links a:hover { color: var(--royal-bright); }
.footer-links svg { width: 22px; height: 22px; }
.footer-copy { font-size: 0.75rem; color: var(--gray-600); margin-top: 0.5rem; }

/* ===== ANIMATIONS ===== */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity var(--duration-slow) var(--ease-out), transform var(--duration-slow) var(--ease-out); }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
    html { scroll-behavior: auto; }
    .reveal { opacity: 1; transform: none; }
    .cursor-glow { display: none; }
    #particleCanvas { display: none; }
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: 1fr; }
    .research-meta-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .menu-toggle { display: flex; }
    .nav-menu {
        position: fixed; top: 0; right: 0; width: 100%; height: 100vh;
        flex-direction: column; background: var(--surface);
        padding: 6rem 2rem 2rem; transform: translateX(100%);
        transition: transform var(--duration-normal) var(--ease-out);
        z-index: 999; justify-content: center; gap: 2rem;
    }
    .nav-menu.active { transform: translateX(0); }
    .nav-menu a { font-size: 1.25rem; color: var(--gray-200); }
    .hero { padding: 6rem 1.5rem 2rem; }
    .hero-title { font-size: clamp(2.5rem, 10vw, 4rem); }
    .hero-meta { flex-direction: column; align-items: center; gap: 0.75rem; }
    .hero-bio { text-align: left; }
    .about-stats { grid-template-columns: 1fr 1fr; }
    .section { padding: var(--space-2xl) 0; }
    .skills-grid { grid-template-columns: 1fr; }
    .edu-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
    .about-stats { grid-template-columns: 1fr; }
    .hero-cta { flex-direction: column; align-items: center; }
    .btn { width: 100%; justify-content: center; }
    .exp-content { padding: 1rem; }
    .research-card { padding: 1.5rem; }
    .research-card-header { flex-direction: column; align-items: flex-start; gap: 0.75rem; }
    .research-meta-grid { grid-template-columns: 1fr; }
    .research-number-bg { font-size: 3.5rem; }
}