/* Buttons */
.btn {
  padding: 0.8rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--primary-color),
    var(--secondary-color)
  );
  color: #fff;
  box-shadow: 0 4px 15px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.4);
}

.btn-secondary {
  background: transparent;
  border: 2px solid var(--glass-border);
  color: var(--text-color);
}

.btn-secondary:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

/* Language Switcher */
.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: 1rem;
}

.lang-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: var(--font-main);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.9rem;
}

.lang-btn:hover,
.lang-btn.active {
  color: var(--primary-color);
}

@media (max-width: 450px) {
  .lang-switch {
    margin-left: 0;
  }
}

/* Theme Switcher */
.theme-selector-wrapper {
  position: relative;
  margin-left: 1rem;
}

.theme-toggle {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.2rem;
  cursor: pointer;
  transition: var(--transition);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

.theme-toggle:hover {
  color: var(--primary-color);
  background: rgba(56, 189, 248, 0.1);
}

.theme-menu {
  position: absolute;
  top: calc(100% + 1rem);
  right: 0;
  background: var(--bg-color);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 0.5rem;
  min-width: 150px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
  z-index: 1000;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.theme-menu.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.theme-option {
  width: 100%;
  background: none;
  border: none;
  color: var(--text-color);
  padding: 0.7rem 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.8rem;
  border-radius: 8px;
  transition: var(--transition);
  font-family: var(--font-main);
  font-size: 0.95rem;
}

.theme-option:hover {
  background: rgba(56, 189, 248, 0.1);
  color: var(--primary-color);
}

.theme-option.active {
  background: rgba(56, 189, 248, 0.2);
  color: var(--primary-color);
}

.theme-preview {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--glass-border);
  flex-shrink: 0;
  box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.06) inset;
}

@media (max-width: 768px) {
  .theme-selector-wrapper {
    margin-left: 0.5rem;
  }

  .theme-menu {
    right: -1rem;
  }
}

@media (max-width: 450px) {
  .theme-selector-wrapper {
    margin-left: 0;
  }
}

/* Back to top button */
.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1.25rem;
  width: 44px; /* overridden by circular style below: 48px */
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-color);
  color: var(--bg-color);
  border: none;
  border-radius: 8px; /* overridden below */
  box-shadow: 0 6px 18px rgba(2, 6, 23, 0.35);
  cursor: pointer;
  z-index: 1200;
  opacity: 0;
  transform: translateY(18px) scale(0.95);
  transition: opacity 300ms cubic-bezier(0.2, 0.9, 0.2, 1),
    transform 300ms cubic-bezier(0.2, 0.9, 0.2, 1);
}
.back-to-top.show {
  opacity: 1;
  transform: translateY(0) scale(1);
}
.back-to-top:focus {
  outline: 3px solid rgba(255, 255, 255, 0.12);
}

/* Make back-to-top circular and add hover effect */
.back-to-top {
  border-radius: 50%;
  width: 48px;
  height: 48px;
  padding: 0;
}
.back-to-top:hover {
  transform: translateY(-6px) scale(1.08);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.45);
  filter: brightness(0.96);
}

/* Section Dividers */
.section-divider {
  width: 100%;
  max-width: 800px;
  height: 2px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--primary-color) 30%,
    var(--secondary-color) 70%,
    transparent
  );
  margin: 0 auto;
  opacity: 0;
  transform: scaleX(0);
  transition: transform 1.2s ease-out, opacity 1.2s ease-out;
  position: relative;
  z-index: 10;
}

.section-divider.expand {
  transform: scaleX(1);
  opacity: 0.6;
}