/* ============================================
   Back to Top Button
   File: frontend/styles/back-to-top.css
   ============================================ */

#back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 9998; /* below quick-view modal (9999) */

  display: flex;
  align-items: center;
  justify-content: center;

  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  overflow: hidden; /* keeps ripple effect contained */

  background-color: var(--primary-color);
  color: var(--white);
  box-shadow: var(--shadow-soft);

  /* hidden by default */
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--transition-fast),
              visibility var(--transition-fast),
              transform var(--transition-fast),
              background-color var(--transition-fast),
              box-shadow var(--transition-fast);
}

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

#back-to-top:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 14px 36px rgba(0, 0, 0, 0.18);
}

#back-to-top:active {
  transform: translateY(1px);
}

/* matches :focus-visible rule in base.css */
#back-to-top:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

#back-to-top svg {
  width: 20px;
  height: 20px;
  stroke: var(--white);
  stroke-width: 2.5;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  /* prevent svg from absorbing ripple click coords */
  pointer-events: none;
}

/* Dark theme — mirrors body.dark-theme button pattern from base.css */
body.dark-theme #back-to-top {
  background-color: var(--primary-color);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
}

body.dark-theme #back-to-top:hover {
  background-color: var(--primary-hover);
}

/* matches @media breakpoint used across style.css */
@media (max-width: 1024px) {
  #back-to-top {
    bottom: 1.25rem;
    right: 1.25rem;
    width: 42px;
    height: 42px;
  }

  #back-to-top svg {
    width: 18px;
    height: 18px;
  }
}