:root {
    --background-color: #EDFBFF;
    --text-color: #14151F;
    --primary-color: #9168FF;
    --secondary-color: #00C2AE;
    --border-color: #dee2e6;
    --link-color: var(--primary-color);
    --header-bg: rgba(237, 251, 255, 0.5);
    --card-bg: #ffffff;
    --accent-color: #87FFB5;

    /* UI */
    --radius: 0.5rem;
    --shadow-xs: 0 1px 2px 0 #0000000D; /* 5% */
    --shadow-sm: 0 1px 3px 0 #0000001A, 0 1px 2px -1px #0000001A; /* 10% */

    --default-transition-duration: .15s;
    --default-transition-timing-function: cubic-bezier(.4,0,.2,1);

    --font-sans: ui-sans-serif,system-ui,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";
    --font-mono: ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;
}

[data-theme="dark"] {
    --background-color: #121212;
    --text-color: #e0e0e0;
    --primary-color: #bb86fc;
    --secondary-color: #b0bec5;
    --border-color: #373737;
    --link-color: #14151F;
    --header-bg: rgba(30, 30, 30, 0.5);
    --card-bg: #1e1e1e;
    --accent-color: #00ff7f;
}

body {
  background-color: var(--background-color);
  color: var(--text-color);
  font-family: var(--font-sans);
  transition: background-color 0.3s, color 0.3s;
  margin: 0;
  padding-top: 5rem; /* nav offset */
}
* {
  box-sizing: border-box;
}
main {
  display: flex;
  flex-direction: column;
  align-items: center;
}
main > section {
  width: 100%;
  max-width: 60rem;
}
@media (max-width: 60rem) {
  main > section {
    padding: 0 20px;
  }
}

/* --- NAVIGATION --- */
nav {
  display: flex;
  justify-content: center;
  height: 5rem;
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  background-image: linear-gradient(to right, rgba(195, 177, 225, 0.5), rgba(125, 225, 243, 0.4));
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 999;
}

nav > div {
  width: 100%;
  max-width: 78rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 36px;
}

.logo {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: transform 300ms ease;
}

/* The hidden glow effect (appears on hover) */
a.logo::after {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  right: -1px;
  bottom: -1px;
  z-index: -10;
  opacity: 0;
  transition: opacity 300ms ease;
  background: radial-gradient(circle, var(--deep-iris-color) 0%, transparent 70%);
  filter: blur(8px);
  transform: scale(0.8);
}

/* Show the glow on hover */
a.logo:hover::after {
  opacity: 0.5;
}

a.logo:hover  {
  transform: scale(1.1);
  transition: transform 300ms ease;
}

.logo img {
  width: 32px;
  height: 32px;
}

/* --- Controls (theme toggle + burger together) --- */
.controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

button#theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  border-radius: 50%;
  background-color: var(--card-bg);
  display: flex;
  justify-content: center;
  align-items: center;
}
button#theme-toggle:hover {
  background-color: var(--secondary-color);
}

.transition-colors {
  transition-property: color, background-color, border-color, outline-color, -webkit-text-decoration-color, text-decoration-color, fill, stroke, --tw-gradient-from, --tw-gradient-via, --tw-gradient-to;
  transition-timing-function: var(--tw-ease, var(--default-transition-timing-function));
  transition-duration: var(--tw-duration, var(--default-transition-duration));
}

button#theme-toggle svg {
  width: 24px;
  height: 24px;
}

button#theme-toggle svg#sun-icon {
  color: #f0b100;
}

button#theme-toggle svg#moon-icon {
  color: #99a1af;
}

/* --- NAV LINKS --- */
.nav-links {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.nav-links a {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 16px;
  font-weight: 500;
  height: 48px;
  min-width: 44px;
  padding: 12px 16px;
  color: var(--text-color);
  text-decoration: none;
  position: relative;
  transition: color 0.3s, background-color 0.3s;
  white-space: nowrap;
  display: none;
  align-items: center;
  gap: 4px;
}

body .nav-links a { /* show 'Home' and 'About' to signed-out users */
  display: flex;
}

body.signed-in .nav-links a {         /* show all nav to signed-in users */
  display: flex;
}

.nav-links a:hover {
  color: var(--primary-color);
  background-color: color-mix(in lab, var(--primary-color) 10%, transparent);
}

.nav-links a.active {
  color: var(--primary-color);
}

.nav-links a.active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0.25rem;
  transform: translateX(-50%);
  width: 6px;
  height: 6px;
  background-color: currentColor;
  border-radius: 50%;
}

/* --- DESKTOP BUTTONS --- */
.nav-actions-desktop {
  display: none;
  gap: 10px;
}

.nav-actions-desktop a.sign-in,
.nav-actions-desktop a.sign-out {
  color: var(--text-color);
  color-scheme: dark;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  font-size: 16px;
  font-weight: 500;
  height: 48px;
  line-height: 24px;
  margin-bottom: 4px;
  margin-left: 0px;
  margin-right: 0px;
  margin-top: 0px;
  min-height: 44px;
  min-width: 44px;
  padding-block-end: 12px;
  padding-block-start: 12px;
  padding-bottom: 12px;
  padding-inline-end: 16px;
  padding-inline-start: 16px;
  padding-left: 16px;
  padding-right: 16px;
  padding-top: 12px;
  position: relative;
  scrollbar-width: none;
  tab-size: 4;
  text-decoration-color: var(--primary-color);
  text-decoration-line: none;
  text-decoration-style: solid;
  text-decoration-thickness: auto;
  text-size-adjust: 100%;
  touch-action: manipulation;
  transition-duration: 0.3s;
  transition-property: all;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
  box-shadow: (in lab, var(--primary-color) 10%, transparent);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  white-space: nowrap;
  background-color: color-mix(in oklab, var(--background-color) 50%, transparent);
}

.nav-actions-desktop a.sign-out {
  color: var(--primary-color);
}

.nav-actions-desktop a.sign-in:hover {
  background-color: color-mix(in lab, var(--accent-color) 100%, transparent);
}

.nav-actions-desktop a.sign-out:hover {
  background-color: color-mix(in lab, var(--primary-color) 100%, transparent);
  color: var(--text-color);
}

.gradient-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  font-size: 14px;
  font-weight: 500;
  border: 1px solid color-mix(in lab, var(--primary-color) 20%, transparent);
  cursor: pointer;
  overflow: hidden;
  height: 48px;
  border-radius: var(--radius);
  background-color: color-mix(in oklab, var(--background-color) 50%, transparent);
  background-image: linear-gradient(
    to right,
    lab(from var(--primary-color) l a b / 0.1) 0%,
    lab(69.9993% -18.9271 -1.65452 / 0.1) 100%
  );
  text-decoration: none;
  color: var(--text-color);
}

.gradient-btn:hover {
  background-color: color-mix(in lab, var(--accent-color) 100%, transparent);
}

.gradient-btn .badge {
  font-size: 12px;
  font-weight: bold;
  background-color: lab(from var(--primary-color) l a b / 0.9);
  color: white;
  padding: 0px 6px;
  border-radius: var(--radius);
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

.gradient-btn .overlay {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, hsla(265, 70%, 60%, 0.2), hsla(185, 65%, 45%, 0.2));
  transform: translateX(-100%);
  transition: transform 0.3s ease-in-out;
  z-index: 0;
}

.gradient-btn:hover .overlay {
  transform: translateX(0);
}

/* --- HAMBURGER --- */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 8px;
}

.hamburger span {
  width: 24px;
  height: 3px;
  background: var(--text-color);
  transition: all 0.3s ease;
}

/* --- MOBILE DROPDOWN --- */
@media (max-width: 48rem) {
  nav > div {
    position: relative;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    flex-direction: column;
    align-items: center;
    background: var(--card-bg);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transition: max-height 0.35s ease, opacity 0.35s ease;
  }

  .nav-links.show {
    max-height: 500px;
    opacity: 1;
  }

  .nav-links a {
    display: flex;
    align-items: center;
    gap: 4px;
    width: 100%;
    justify-content: center;
    padding: 6px 8px;
  }

  .hamburger {
    display: flex;
  }

  .nav-actions-desktop {
    display: none;
  }
}

/* --- DESKTOP --- */
@media (min-width: 48rem) {
  body.signed-in .nav-links a.sign-out {
    display: none;
  }
  .nav-links a {
    border-radius: var(--radius);
  }
  .nav-links a.sign-out {
    display: none;
  }
  .nav-actions-desktop {
    display: flex;
  }
}