:root {
  --bg-body: #18191c;
  --bg-card: #24262b;
  --bg-card-hover: #2f3136;
  --text-main: #ebebeb;
  --text-muted: #b9bbbe;
  --accent-color: #00d9f6;
  --border-color: #383c44;
  --radius-std: 12px;
}

* {
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  width: 100%;
  background-color: var(--bg-body);
  background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)),
    url("/img/fond.jpg");
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  color: var(--text-main);
  font-size: 18px;
  line-height: 1.6;
}

header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  z-index: 1000;
  background: rgba(24, 25, 28, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--accent-color);
  display: flex;
  align-items: center;
  padding: 0 2rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

main {
  padding-top: 120px;
  padding-bottom: 50px;
  width: 100%;
  min-height: 80vh;
}

div.title {
  text-align: center;
  margin-bottom: 3rem;
}

h2 span {
  display: inline-block;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--accent-color);
  border-radius: var(--radius-std);
  padding: 1rem 2rem;
  text-transform: uppercase;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 2px;
  backdrop-filter: blur(5px);
  transition: all 0.3s ease;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

h2 span:hover {
  transform: translateY(-5px);
  border-color: var(--accent-color);
  box-shadow: 0 0 20px rgba(0, 217, 246, 0.2);
}

.cards {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2rem;
  padding: 0 2rem;
}

section {
  flex: 1 1 300px;
  max-width: 400px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-std);
  padding: 2rem;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
  overflow: hidden;
}

section:hover {
  transform: translateY(-10px);
  background-color: var(--bg-card-hover);
  border-color: var(--accent-color);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.5);
}

section h3 {
  color: var(--accent-color);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
  text-align: center;
  text-transform: uppercase;
  font-size: 1.2rem;
  letter-spacing: 1px;
}

section blockquote {
  font-family: "Segoe UI", sans-serif;
  color: var(--text-muted);
  font-style: normal;
  border-left: 3px solid var(--border-color);
  padding-left: 1rem;
  margin-bottom: 1rem;
  font-size: 1rem;
}

section blockquote:hover {
  border-left-color: var(--accent-color);
  color: var(--text-main);
}

.dev,
.access,
.defi {
  background: linear-gradient(145deg, var(--bg-card), #2a2d33);
}

footer {
  width: 100%;
  background-color: #18191c;
  border-top: 1px solid #00d9f6;
  color: #ebebeb;
  padding-top: 60px;
  font-size: 0.95rem;
  margin-top: 50px;
  position: relative;
  z-index: 10;
}

.footer-content {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 40px;
  padding-bottom: 40px;
}

.footer-section {
  flex: 1;
  min-width: 250px;
}

.footer-section h3 {
  color: #00d9f6;
  font-family: "Segoe UI", sans-serif;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-weight: 800;
  margin-bottom: 25px;
  font-size: 1.2rem;
  position: relative;
  display: inline-block;
  border: none;
}

.footer-section h3::after {
  content: "";
  display: block;
  width: 40px;
  height: 3px;
  background-color: #00d9f6;
  margin-top: 8px;
  box-shadow: 0 0 10px rgba(0, 217, 246, 0.5);
  border-radius: 2px;
}

.footer-section p {
  line-height: 1.8;
  color: #b9bbbe;
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
  border: none;
  background: transparent;
}

.footer-section ul li {
  margin-bottom: 12px;
}

.footer-section ul li a {
  text-decoration: none;
  color: #b9bbbe;
  font-weight: 500;
  transition: all 0.3s ease;
  display: inline-block;
}

.footer-section ul li a:hover {
  color: #00d9f6;
  padding-left: 10px;
  text-shadow: 0 0 8px rgba(0, 217, 246, 0.4);
}

.footer-bottom {
  background-color: #121315;
  text-align: center;
  padding: 20px 0;
  border-top: 1px solid #383c44;
  font-size: 0.85rem;
  color: #777;
}

.footer-bottom span {
  color: #00d9f6;
}

.btn-register {
  display: block;
  width: 100%;
  padding: 12px;
  border-radius: 6px;
  border: none;
  background-color: #00d9f6;
  color: #18191c;
  font-weight: bold;
  text-transform: uppercase;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s;
  letter-spacing: 1px;
  margin-top: 15px;
}

.btn-register:hover {
  box-shadow: 0 0 15px rgba(0, 217, 246, 0.6);
  transform: translateY(-2px);
}
.featured-wrapper {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 4rem;
  padding: 0 1rem;
}

.featured-lesson {
  width: 100%;
  max-width: 1200px;
  background: linear-gradient(90deg, #24262b 0%, #1e2024 100%);
  border: 1px solid #383c44;
  border-left: 4px solid #00d9f6;
  border-radius: 12px;
  padding: 2rem 3rem;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  transition: transform 0.3s ease;
}

.featured-lesson:hover {
  transform: translateY(-3px);
  border-color: #00d9f6;
  box-shadow: 0 15px 40px rgba(0, 217, 246, 0.15);
}

.featured-lesson::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(
    circle at right,
    rgba(0, 217, 246, 0.05) 0%,
    transparent 60%
  );
  pointer-events: none;
}

.featured-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  flex: 1;
  padding-right: 20px;
  z-index: 2;
}
.btn-play {
  background-color: #00d9f6;
  color: #18191c;
  padding: 12px 30px;
  border-radius: 50px;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
  font-size: 0.95rem;
  transition: all 0.3s;
  white-space: nowrap;
  box-shadow: 0 0 15px rgba(0, 217, 246, 0.3);
  display: inline-block;
}

.btn-play:hover {
  box-shadow: 0 0 25px rgba(0, 217, 246, 0.6);
  transform: scale(1.05);
}