/* MEDIA QUERIES */

@media (min-width: 480px) {
  .container h2 {
    padding: 0.9rem 1.1rem;
  }

  .container .btn {
    padding: 0.95rem 1.5rem;
  }
  .container .color-chip {
    width: 44px;
    height: 44px;
    border-radius: 6px;
  }
}

@media (min-width: 768px) {
  body {
    padding: 1.75rem 2rem;
  }
  nav {
    padding: 1rem 1.25rem;
    border-radius: 10px;
  }

  .nav-links {
    gap: 1rem;
  }
  .container {
    max-width: 720px;
    margin: 0 auto;
  }

  .container .btn {
    padding: 1rem 1.75rem;
  }

  .footer {
    border-radius: 10px;
  }
  .footer-content {
    flex-direction: row;
    text-align: left;
    justify-content: space-between;
  }
}

@media (min-width: 1024px) {
  body {
    padding: 2.5rem 3rem;
  }

  .container {
    max-width: 900px;
    border-radius: 16px;
  }

  .container .btn {
    padding: 1.1rem 2rem;
  }
  .container .color-chip {
    width: 50px;
    height: 50px;
  }
}

/* Mobile-first responsive stylesheet for Color Flipper */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* VARIABLES */
:root {
  /* COLOR */
  --WHITE: #fff;
  --BG-LINEAR: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
  --GRAY-LIGHT: #617d98;
  --GRAY: hsl(204, 100%, 96%);
  --DARK: #222;
  --BG-BLACK: #000;
  --BG-WHITE-TRANSPARENT: rgba(255, 255, 255, 0.8);
  --BG-BLACK-TRANSPARENT: rgba(0, 0, 0, 0.5);

  /* FONT SIZES */
  --FONT-SIZE-XS: clamp(1rem, 3vw, 1.2rem);
  /* --FONT-SIZE-SM: clamp(1.25rem, 3vw, 1.5rem); */
  --FONT-SIZE-MD: clamp(1.25rem, 3vw, 1.5rem);
  --FONT-SIZE-LG: clamp(1.25rem, 3vw, 2rem);
  --FONT-SIZE-XL: clamp(1.4rem, 5vw, 3rem);

  /* SHADOWS */
  --SHADOW-SOFT: 0 4px 12px rgba(0, 0, 0, 0.1);
  --SHADOW-STRONG: 0 6px 18px rgba(38, 78, 99, 0.3);

  /* TRANSITIONS */
  --TRANSITION: all 0.3s ease;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--WHITE);
  min-height: 100vh;
  line-height: 1.4;
  color: var(--DARK);
  /* padding: 1rem; breathing room on mobile */
  display: flex;
  flex-direction: column;
  transition: background-color 0.6s ease-in-out;
}

/* NAV */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  background-color: var(--WHITE);
  padding: 1rem 1rem;
  /* border-radius: 10px; */
  box-shadow: var(--SHADOW-STRONG);
  /* border: 2px solid #000; */
}

nav h1 {
  font-size: var(--FONT-SIZE-XL);
  color: #0080f8;
  text-shadow: var(--SHADOW-STRONG);
}

.nav-links {
  display: flex;
  gap: clamp(0.4rem, 5vw, 2rem);
}

.nav-btn {
  background-color: transparent;
  padding: clamp(0.35rem, 3vw, 0.5rem) clamp(0.5rem, 3vw, 1.5rem);
  font-size: var(--FONT-SIZE-MD);
  font-weight: bold;
  color: var(--DARK);
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  box-shadow: var(--SHADOW-SOFT);
}

.nav-links .active {
  background-color: var(--GRAY-LIGHT);
  color: var(--WHITE);
}

.nav-btn:hover:not(.active) {
  background-color: var(--BG-BLACK-TRANSPARENT);
  color: var(--WHITE);
  border: 1px solid var(--WHITE);
  backdrop-filter: blur(10px);
  transition: var(--TRANSITION);
}

main {
  margin-top: 1rem;
  flex-grow: 1;
}

.container {
  display: flex;
  flex-direction: column;
  text-align: center;
  background-color: transparent;
  padding: clamp(1rem, 5vw, 2rem);
  border-radius: 12px;
  box-shadow: var(--SHADOW-STRONG);
  max-width: 800px;
  width: 100%;
}

.container h2 {
  background-color: var(--DARK);
  color: var(--WHITE);
  border-radius: 8px;
  padding: 0.75rem 0.75rem;
  margin-bottom: 1rem;
  font-weight: 500;
  display: inline-block;
  font-size: var(--FONT-SIZE-LG);
  box-shadow: var(--SHADOW-STRONG);
}

.container .current-color {
  display: block;
  font-size: var(--FONT-SIZE-LG);
  margin-top: 0.5rem;
  color: #0080f8;
  font-weight: 600;
}

.container .btn,
.copy-btn {
  background-color: var(--GRAY);
  color: var(--DARK);
  padding: 0.85rem 1.25rem;
  margin: 0.9rem 0;
  font-size: var(--FONT-SIZE-MD);
  font-weight: 700;
  border: 2px solid var(--DARK);
  border-radius: 10px;
  cursor: pointer;
  transition: var(--TRANSITION);
}

.copy-btn {
  max-width: 200px;
  margin: 0.5rem auto 1rem auto;
}

.container .btn:hover,
.copy-btn:hover {
  transform: translateY(-2px);
  color: var(--WHITE);
  background-color: var(--DARK);
}

#copy-msg {
  padding: clamp(0.25rem, 3vw, 0.5rem);
  background-color: rgba(0, 249, 0, 0.5);
  border: 1px solid rgba(0, 128, 0, 0.2);
  border-radius: 6px;
  font-size: var(--FONT-SIZE-XS);
  font-weight: 500;
  color: var(--DARK);
  opacity: 0;
  transition: opacity 0.3s ease;
  margin-top: -0.8rem;
}

.container .instructions {
  font-size: var(--FONT-SIZE-XS);
  color: var(--WHITE);
  font-weight: 500;
  margin-top: 0.9rem;
  line-height: 1.45;
  background-color: var(--BG-BLACK-TRANSPARENT);
  padding: 0.85rem 1rem;
  border-radius: 8px;
}

.container .color-history {
  margin-top: 0.85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  max-width: 100%;
}

.container .color-chip {
  width: 40px;
  height: 40px;
  border-radius: 6px;
  border: 2px solid var(--GRAY);
  cursor: pointer;
  transition: var(--TRANSITION);
}

.container .color-chip:hover {
  transform: scale(1.06);
  border-color: var(--DARK);
}

.container .color-chip:active {
  transform: scale(0.98);
}

.container .instructions ul {
  text-align: left;
  padding-left: 1.25rem;
  display: inline-block;
  margin-top: 0.5rem;
  list-style-type: square;
}

/* Footer (mobile-friendly stacking) */
.footer {
  background: var(--BG-LINEAR);
  color: white;
  padding: 1.5rem 1rem;
  margin-top: 1.25rem;
}

.footer-content {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.75rem;
  flex-direction: column;
  text-align: center;
}

.developer-info {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.dev-name {
  font-size: var(--FONT-SIZE-MD);
  font-weight: 600;
  color: #ecf0f1;
}
.dev-title {
  color: #bdc3c7;
  font-size: var(--FONT-SIZE-XS);
}

.github-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: rgba(255, 255, 255, 0.1);
  border: 2px solid rgba(255, 255, 255, 0.2);
  border-radius: 50px;
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: var(--TRANSITION);
  backdrop-filter: blur(10px);
}

.github-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--SHADOW-STRONG);
}

.github-icon {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.footer-bottom {
  margin-top: 0.9rem;
  color: #95a5a6;
  font-size: var(--FONT-SIZE-XS);
  text-align: center;
}