*, *::before, *::after {
  box-sizing: border-box;
}

body {
  font-family: system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  margin: 0;
  background: #f1f5f9;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.gooey-nav-wrapper {
  background: #ffffff;
  padding: 12px;
  border-radius: 40px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1);
  /* Apply the SVG Gooey Filter to the container */
  filter: url("#goo-filter");
}

.nav-container {
  position: relative;
  display: flex;
  gap: 10px;
}

.nav-item {
  position: relative;
  z-index: 2;
  padding: 12px 24px;
  font-weight: 600;
  font-size: 1rem;
  color: #64748b;
  cursor: pointer;
  border-radius: 30px;
  transition: color 0.3s ease;
  user-select: none;
}

.nav-item.active-tab {
  color: #ffffff;
}

.active-pill {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 110px; /* Default width, dynamically updated by JS */
  background: #3b82f6;
  border-radius: 30px;
  z-index: 1;
  transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1), width 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
  will-change: transform, width;
}

const tabs = document.querySelectorAll(".nav-item");
const pill = document.getElementById("active-pill");
const container = document.querySelector(".nav-container");

function updatePill(targetTab) {
  /* Remove active class from all */
  tabs.forEach(function(t) {
    t.classList.remove("active-tab");
  });
  
  /* Add active class to clicked */
  targetTab.classList.add("active-tab");
  
  /* Calculate physical bounds for perfect pill alignment */
  const tabRect = targetTab.getBoundingClientRect();
  const containerRect = container.getBoundingClientRect();
  
  const offsetLeft = tabRect.left - containerRect.left;
  const newWidth = tabRect.width;
  
  /* Slide and stretch the background pill */
  pill.style.width = newWidth + "px";
  pill.style.transform = "translateX(" + offsetLeft + "px)";
}

/* Initialize first tab */
updatePill(document.getElementById("tab-1"));

tabs.forEach(function(tab) {
  tab.addEventListener("click", function() {
    updatePill(tab);
  });
});

window.addEventListener("resize", function() {
  const active = document.querySelector(".active-tab");
  if (active) updatePill(active);
});