/* ============================================
   eBDES — UNEMAT | Site Institucional
   Paleta: Azul Escuro + Verde Tecnológico
   Fonte: Inter (Google Fonts)
   ============================================ */

/* ========== VARIÁVEIS ========== */
:root {
    /* Cores principais */
    --primary: #0f4c81;
    --primary-dark: #0a3560;
    --primary-light: #1a6bb5;
    --accent: #00d4aa;
    --accent-dark: #00b892;
    --accent-light: #33debb;

    /* Neutros */
    --bg-white: #ffffff;
    --bg-light: #f5f7fa;
    --bg-dark: #0c1929;
    --bg-section: #f0f4f8;

    /* Texto */
    --text-dark: #1a2332;
    --text-medium: #4a5568;
    --text-light: #8896a6;
    --text-white: #ffffff;
    --text-on-dark: #cbd5e0;

    /* Efeitos */
    --shadow-sm: 0 2px 8px rgba(15, 76, 129, 0.08);
    --shadow-md: 0 4px 20px rgba(15, 76, 129, 0.12);
    --shadow-lg: 0 8px 40px rgba(15, 76, 129, 0.16);
    --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 8px 30px rgba(15, 76, 129, 0.2);

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 50%;

    /* Transições */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== RESET & BASE ========== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-dark);
    background: var(--bg-white);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

img {
    max-width: 100%;
    display: block;
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

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

/* ========== NAVBAR ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 18px 0;
    transition: var(--transition);
    background: transparent;
}

.navbar.scrolled {
    background: rgba(12, 25, 41, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 10px 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-white);
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--accent), var(--primary-light));
    border-radius: var(--radius-sm);
    font-size: 1rem;
    color: white;
}

.nav-menu {
    display: flex;
    gap: 8px;
}

.nav-link {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-white);
    background: rgba(0, 212, 170, 0.15);
}

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

/* Hamburger */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: white;
    transition: var(--transition);
    border-radius: 2px;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}
.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========== HERO ========== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--bg-dark) 0%, var(--primary-dark) 50%, var(--primary) 100%);
    overflow: hidden;
}

.hero-particles {
    position: absolute;
    inset: 0;
    z-index: 1;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 20% 50%, rgba(0, 212, 170, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(26, 107, 181, 0.15) 0%, transparent 50%);
    z-index: 2;
}

.hero-content {
    position: relative;
    z-index: 3;
    text-align: center;
    padding: 120px 0 80px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 212, 170, 0.12);
    border: 1px solid rgba(0, 212, 170, 0.25);
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
    padding: 8px 20px;
    border-radius: 50px;
    margin-bottom: 24px;
    letter-spacing: 0.5px;
}

.hero-title {
    font-size: clamp(3.5rem, 8vw, 7rem);
    font-weight: 800;
    color: var(--text-white);
    letter-spacing: -2px;
    line-height: 1;
    margin-bottom: 16px;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    font-weight: 300;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.hero-description {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.6);
    max-width: 600px;
    margin: 0 auto 36px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    color: var(--bg-dark);
    border-color: var(--accent);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--accent-light), var(--accent));
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 212, 170, 0.35);
}

.btn-outline {
    background: transparent;
    color: var(--text-white);
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(0, 212, 170, 0.08);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* Hero Stats */
.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--accent);
    font-family: 'Fira Code', monospace;
}

.stat-label {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

/* Hero scroll indicator */
.hero-scroll {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
}

.hero-scroll a {
    color: rgba(255, 255, 255, 0.4);
    font-size: 1.2rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* ========== SECTIONS ========== */
.section {
    padding: 100px 0;
}

.section-dark {
    background: var(--bg-section);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--primary);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    color: var(--text-dark);
    letter-spacing: -1px;
    margin-bottom: 16px;
}

.section-line {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    margin: 0 auto;
    border-radius: 2px;
}

.section-description {
    text-align: center;
    color: var(--text-medium);
    max-width: 600px;
    margin: -30px auto 50px;
    font-size: 1.05rem;
}

/* ========== SOBRE ========== */
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: start;
}

.about-text p {
    color: var(--text-medium);
    margin-bottom: 20px;
    font-size: 1.02rem;
}

.about-text strong {
    color: var(--text-dark);
}

.about-highlight {
    display: flex;
    gap: 16px;
    padding: 24px;
    background: linear-gradient(135deg, rgba(15, 76, 129, 0.05), rgba(0, 212, 170, 0.05));
    border-left: 4px solid var(--accent);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin-top: 24px;
}

.about-highlight > i {
    font-size: 1.5rem;
    color: var(--accent);
    margin-top: 4px;
}

.about-highlight strong {
    display: block;
    color: var(--primary);
    margin-bottom: 6px;
    font-size: 1.05rem;
}

.about-highlight p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

.about-image {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.about-card {
    padding: 28px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.about-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.about-card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    border-radius: var(--radius-sm);
    font-size: 1.1rem;
    margin-bottom: 14px;
}

.about-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 4px;
}

.about-card p {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* ========== LINHAS DE PESQUISA ========== */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.research-card {
    padding: 32px 28px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0);
    transition: var(--transition);
    transform-origin: left;
}

.research-card:hover::before {
    transform: scaleX(1);
}

.research-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.research-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(15, 76, 129, 0.08), rgba(0, 212, 170, 0.08));
    color: var(--primary);
    border-radius: var(--radius-md);
    font-size: 1.4rem;
    margin-bottom: 18px;
    transition: var(--transition);
}

.research-card:hover .research-icon {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
}

.research-card h3 {
    font-size: 1.08rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.research-card p {
    font-size: 0.9rem;
    color: var(--text-medium);
    line-height: 1.6;
}

/* ========== VÍNCULOS ========== */
.vinculos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
    margin-bottom: 50px;
}

.vinculo-card {
    display: flex;
    gap: 20px;
    padding: 32px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.vinculo-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.vinculo-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: rgba(15, 76, 129, 0.1);
    font-family: 'Fira Code', monospace;
    line-height: 1;
}

.vinculo-content h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.vinculo-content p {
    font-size: 0.92rem;
    color: var(--text-medium);
    margin-bottom: 12px;
}

.vinculo-tag {
    display: inline-block;
    padding: 4px 14px;
    background: rgba(0, 212, 170, 0.1);
    color: var(--accent-dark);
    font-size: 0.78rem;
    font-weight: 600;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.vinculos-institutions {
    text-align: center;
    padding: 40px;
    background: linear-gradient(135deg, rgba(15, 76, 129, 0.03), rgba(0, 212, 170, 0.03));
    border-radius: var(--radius-lg);
    border: 1px dashed rgba(15, 76, 129, 0.15);
}

.vinculos-institutions h3 {
    font-size: 1.1rem;
    color: var(--text-dark);
    margin-bottom: 24px;
    font-weight: 700;
}

.institutions-logos {
    display: flex;
    justify-content: center;
    gap: 60px;
    flex-wrap: wrap;
}

.institution {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.institution i {
    font-size: 2.5rem;
    color: var(--primary);
    opacity: 0.6;
}

.institution span {
    font-weight: 700;
    color: var(--primary);
    font-size: 1rem;
    letter-spacing: 1px;
}

/* ========== MEMBROS ========== */
.membros-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.membro-card {
    text-align: center;
    padding: 36px 24px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.membro-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.membro-avatar {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-full);
    color: white;
    font-size: 2rem;
}

.membro-card h3 {
    font-size: 1.08rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 4px;
}

.membro-role {
    font-size: 0.85rem;
    color: var(--accent-dark);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
}

.membro-desc {
    font-size: 0.88rem;
    color: var(--text-light);
    margin-bottom: 16px;
}

.membro-links {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.membro-links a {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 6px 14px;
    font-size: 0.8rem;
    color: var(--primary);
    background: rgba(15, 76, 129, 0.06);
    border-radius: 50px;
    font-weight: 500;
}

.membro-links a:hover {
    background: var(--primary);
    color: white;
}

.membros-note {
    text-align: center;
    color: var(--text-light);
    font-size: 0.92rem;
    padding: 20px;
    background: rgba(15, 76, 129, 0.04);
    border-radius: var(--radius-md);
}

.membros-note a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: underline;
}

.membros-note i {
    color: var(--primary);
    margin-right: 4px;
}

/* ========== PUBLICAÇÕES ========== */
.pub-filters {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.pub-filter {
    padding: 10px 24px;
    background: transparent;
    border: 2px solid rgba(15, 76, 129, 0.15);
    color: var(--text-medium);
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.pub-filter:hover,
.pub-filter.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.pub-list {
    max-width: 800px;
    margin: 0 auto 30px;
}

.pub-item {
    display: flex;
    gap: 24px;
    padding: 28px;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    margin-bottom: 16px;
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: var(--transition);
}

.pub-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.pub-year {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    font-family: 'Fira Code', monospace;
    min-width: 60px;
}

.pub-type-tag {
    display: inline-block;
    padding: 3px 12px;
    background: rgba(15, 76, 129, 0.1);
    color: var(--primary);
    font-size: 0.72rem;
    font-weight: 700;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.tag-dissertacao {
    background: rgba(0, 212, 170, 0.1);
    color: var(--accent-dark);
}

.tag-tcc {
    background: rgba(255, 165, 0, 0.1);
    color: #e67e00;
}

.pub-info h4 {
    font-size: 1.05rem;
    color: var(--text-dark);
    font-weight: 700;
    margin-bottom: 6px;
}

.pub-authors {
    font-size: 0.88rem;
    color: var(--text-medium);
    margin-bottom: 6px;
}

.pub-venue {
    font-size: 0.85rem;
    color: var(--text-light);
}

.pub-venue i {
    margin-right: 4px;
    color: var(--primary);
}

.pub-note {
    text-align: center;
    color: var(--text-light);
    font-size: 0.88rem;
    padding: 16px;
    background: rgba(255, 165, 0, 0.06);
    border: 1px dashed rgba(255, 165, 0, 0.3);
    border-radius: var(--radius-md);
    max-width: 800px;
    margin: 0 auto;
}

.pub-note i {
    color: #e67e00;
}

/* ========== CONTATO ========== */
.contato-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.contato-item {
    display: flex;
    gap: 16px;
    margin-bottom: 28px;
}

.contato-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 212, 170, 0.1);
    color: var(--accent-dark);
    border-radius: var(--radius-sm);
    font-size: 1.1rem;
    flex-shrink: 0;
}

.contato-item h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 4px;
}

.contato-item p {
    font-size: 0.9rem;
    color: var(--text-on-dark);
    line-height: 1.6;
}

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

.contato-item a:hover {
    text-decoration: underline;
}

.contato-social {
    display: flex;
    gap: 12px;
    margin-top: 10px;
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-on-dark);
    border-radius: var(--radius-sm);
    font-size: 1.1rem;
    transition: var(--transition);
}

.social-link:hover {
    background: var(--accent);
    color: var(--bg-dark);
    transform: translateY(-3px);
}

/* Form */
.contato-form-wrapper {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 36px;
}

.form-group {
    position: relative;
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    background: rgba(255, 255, 255, 0.06);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--text-white);
    font-size: 0.95rem;
    font-family: inherit;
    transition: var(--transition);
    outline: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    background: rgba(0, 212, 170, 0.04);
}

.form-group label {
    position: absolute;
    top: -8px;
    left: 12px;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--bg-section);
    padding: 0 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0;
    transition: var(--transition);
}

.form-group input:focus ~ label,
.form-group textarea:focus ~ label {
    opacity: 1;
}

.section-dark .contato-form-wrapper {
    background: rgba(12, 25, 41, 0.3);
}

.section-dark .form-group label {
    background: var(--bg-section);
}

/* ========== FOOTER ========== */
.footer {
    background: var(--bg-dark);
    padding: 60px 0 0;
    color: var(--text-on-dark);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 800;
    color: white;
    margin-bottom: 14px;
}

.footer-about p {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.7;
}

.footer-links h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 18px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
    padding-left: 4px;
}

.footer-bottom {
    text-align: center;
    padding: 24px 0;
    font-size: 0.82rem;
    color: rgba(255, 255, 255, 0.3);
}

/* ========== BACK TO TOP ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow-md);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* ========== ANIMAÇÕES ========== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: var(--transition-slow);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========== RESPONSIVO ========== */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-image {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .about-card {
        flex: 1;
        min-width: 200px;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--bg-dark);
        flex-direction: column;
        padding: 80px 30px 30px;
        gap: 4px;
        transition: var(--transition);
        box-shadow: -10px 0 30px rgba(0, 0, 0, 0.3);
    }

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

    .nav-link {
        padding: 12px 16px;
        font-size: 1rem;
    }

    .hero-title {
        font-size: 3.5rem;
    }

    .hero-stats {
        gap: 30px;
    }

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

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

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .pub-item {
        flex-direction: column;
        gap: 12px;
    }

    .research-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.8rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .section {
        padding: 70px 0;
    }

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

    .institutions-logos {
        gap: 30px;
    }
}