html,
body {
  min-height: 100%;
  margin: 0;
  overflow-x: hidden;
}

body {
  font-family: 'Inter', sans-serif;
  background-image: url('img/fondo.png?v=20260421');
  background-size: cover;
  background-position: center top;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-color: #1570c5;
}

.panel-glow {
  background: rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(2px);
  border: 2px solid rgba(22, 148, 236, 0.55);
  box-shadow:
    0 0 0 1px rgba(27, 171, 255, 0.22),
    0 0 28px rgba(0, 133, 255, 0.14),
    inset 0 0 18px rgba(255, 255, 255, 0.06);
}

.course-btn {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(0, 145, 255, 0.95);
  background: linear-gradient(
    180deg,
    rgba(14, 18, 20, 0.98) 0%,
    rgba(6, 9, 10, 0.98) 100%
  );
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    inset 0 -10px 22px rgba(255, 255, 255, 0.02),
    0 0 0 1px rgba(0, 156, 255, 0.48),
    0 0 18px rgba(0, 157, 255, 0.34);
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease,
    border-color 0.25s ease,
    background 0.25s ease;
}

.course-btn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.08),
    rgba(255, 255, 255, 0)
  );
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.course-btn:hover {
  transform: translateY(-3px) scale(1.015);
  border-color: rgba(160, 95, 255, 1);
  background: linear-gradient(
    180deg,
    #227afb 0%,
    #227afb 100%
  );
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.22),
    inset 0 -10px 24px rgba(13, 5, 80, 0.42),
    0 0 0 1px rgba(173, 116, 255, 0.75),
    0 0 28px rgba(135, 85, 255, 0.65),
    0 14px 32px rgba(0, 0, 0, 0.22);
}

.course-btn:hover::before {
  opacity: 0.35;
}

.course-title {
  transition:
    color 0.25s ease,
    transform 0.25s ease,
    letter-spacing 0.25s ease,
    text-shadow 0.25s ease;
}

.course-btn:hover .course-title {
  color: #ffffff;
  transform: translateX(4px);
  letter-spacing: 0.2px;
  text-shadow:
    0 0 8px rgba(255, 255, 255, 0.45),
    0 0 18px rgba(196, 166, 255, 0.45);
}

.course-btn:hover .click-badge {
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.24),
    rgba(255, 255, 255, 0.08)
  );
  border-color: rgba(255, 255, 255, 0.36);
  transform: rotate(-4deg) scale(1.08);
}

.click-badge {
  background: linear-gradient(
    180deg,
    rgba(70, 51, 120, 0.86),
    rgba(24, 18, 55, 0.96)
  );
  border: 1px solid rgba(255, 255, 255, 0.16);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    0 0 14px rgba(143, 118, 255, 0.28);
  backdrop-filter: blur(3px);
}

.site-logo {
  display: block;
  height: auto;
  filter: drop-shadow(0 10px 30px rgba(0, 0, 0, 0.22));
}

.button-icon {
  display: block;
  height: auto;
  filter: drop-shadow(0 3px 10px rgba(0, 0, 0, 0.2));
}

.subtitle-highlight {
  color: #1769ff;
  text-decoration: underline;
  text-decoration-color: #1769ff;
  text-decoration-thickness: 3px;
  text-underline-offset: 4px;
}

@media (max-width: 768px) {
  body {
    background-attachment: scroll;
    background-position: center top;
  }
}