@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  /* Colors - Light Theme Default */
  --bg-color: #f8fafc;
  --text-main: #0f172a;
  --text-muted: #475569;
  --card-bg: #ffffff;
  --card-border: rgba(226, 232, 240, 0.8);
  --card-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);
  --card-shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --accent-color: #4f46e5;
  --tag-bg-blue: #eff6ff;
  --tag-text-blue: #1d4ed8;
  --tag-bg-purple: #f3e8ff;
  --tag-text-purple: #6b21a8;
  --tag-bg-green: #ecfdf5;
  --tag-text-green: #047857;
  --header-bg: rgba(255, 255, 255, 0.8);
  --lang-btn-bg: #f1f5f9;
  --lang-btn-text: #475569;
  --lang-btn-active-bg: #4f46e5;
  --lang-btn-active-text: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Colors - Dark Theme */
    --bg-color: #0b0f19;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --card-bg: #151c2c;
    --card-border: rgba(30, 41, 59, 0.8);
    --card-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.2), 0 2px 4px -2px rgb(0 0 0 / 0.2);
    --card-shadow-hover: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --accent-color: #818cf8;
    --tag-bg-blue: rgba(30, 58, 138, 0.3);
    --tag-text-blue: #93c5fd;
    --tag-bg-purple: rgba(88, 28, 135, 0.3);
    --tag-text-purple: #d8b4fe;
    --tag-bg-green: rgba(6, 78, 59, 0.3);
    --tag-text-green: #6ee7b7;
    --header-bg: rgba(15, 23, 42, 0.8);
    --lang-btn-bg: #1e293b;
    --lang-btn-text: #94a3b8;
    --lang-btn-active-bg: #6366f1;
    --lang-btn-active-text: #ffffff;
  }
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  padding-bottom: 4rem;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Bilingual switching system */
html:not(.lang-pt) [lang="pt"] {
  display: none !important;
}
html:not(.lang-en) [lang="en"] {
  display: none !important;
}

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

/* Header & Navigation styling */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--card-border);
  padding: 1rem 0;
  margin-bottom: 3rem;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05);
}

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

.logo-section h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-section p {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Language selector toggle button */
.lang-selector {
  display: flex;
  background-color: var(--lang-btn-bg);
  padding: 0.25rem;
  border-radius: 9999px;
  border: 1px solid var(--card-border);
}

.lang-selector button {
  background: none;
  border: none;
  padding: 0.4rem 1rem;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: 9999px;
  cursor: pointer;
  color: var(--lang-btn-text);
  transition: all 0.2s ease;
}

.lang-selector button.active {
  background-color: var(--lang-btn-active-bg);
  color: var(--lang-btn-active-text);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Section Title layout */
section {
  margin-bottom: 4rem;
}

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  position: relative;
  display: inline-block;
  padding-bottom: 0.5rem;
}

.section-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 40px;
  height: 4px;
  background: var(--primary-gradient);
  border-radius: 2px;
}

/* Grid Layout for Cards */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(480px, 1fr));
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
}

/* Glassmorphism/Premium Card styling */
.card {
  background-color: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.75rem;
  box-shadow: var(--card-shadow);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
}

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

.card-icon {
  margin-bottom: 1.25rem;
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.card-link {
  display: inline-flex;
  align-items: center;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent-color);
  text-decoration: none;
  transition: opacity 0.2s ease;
  margin-top: auto;
}

.card-link:hover {
  opacity: 0.8;
}

.card-link svg {
  margin-left: 0.4rem;
  transition: transform 0.2s ease;
}

.card-link:hover svg {
  transform: translateX(3px);
}

/* Badge tags inside cards */
.badge-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-blue {
  background-color: var(--tag-bg-blue);
  color: var(--tag-text-blue);
}

.badge-purple {
  background-color: var(--tag-bg-purple);
  color: var(--tag-text-purple);
}

.badge-green {
  background-color: var(--tag-bg-green);
  color: var(--tag-text-green);
}

/* Academic Production card variants */
.academic-card {
  border-left: 5px solid var(--accent-color);
}

.academic-card h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-color);
  margin-bottom: 0.5rem;
}

.academic-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.academic-meta span {
  display: flex;
  align-items: center;
}

.academic-meta svg {
  margin-right: 0.35rem;
}

/* Resources list layout */
.resource-list {
  list-style: none;
}

.resource-item {
  display: flex;
  align-items: flex-start;
  padding: 1.25rem;
  border-bottom: 1px solid var(--card-border);
  transition: background-color 0.2s ease;
  border-radius: 8px;
}

.resource-item:hover {
  background-color: rgba(99, 102, 241, 0.04);
}

.resource-item:last-child {
  border-bottom: none;
}

.resource-icon {
  margin-right: 1rem;
  margin-top: 0.2rem;
  color: var(--accent-color);
}

.resource-content {
  flex-grow: 1;
}

.resource-content h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.resource-content p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

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

.resource-btn {
  display: inline-flex;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.35rem 0.85rem;
  border-radius: 6px;
  text-decoration: none;
  background-color: var(--lang-btn-bg);
  color: var(--text-main);
  border: 1px solid var(--card-border);
  transition: all 0.2s ease;
}

.resource-btn:hover {
  background-color: var(--accent-color);
  color: white;
  border-color: var(--accent-color);
}

.resource-btn svg {
  margin-right: 0.35rem;
}

/* Footer styling */
footer {
  text-align: center;
  margin-top: 5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--card-border);
  color: var(--text-muted);
  font-size: 0.9rem;
}