:root {
  /* Light Mode Colors */
  --clr-primary: #0d9488;
  /* Teal-600 */
  --clr-primary-light: #14b8a6;
  /* Teal-400 */
  --clr-primary-dark: #115e59;
  /* Teal-700 */
  --clr-accent: #2563eb;
  /* Blue-600 */
  --clr-accent-light: #93c5fd;
  /* Blue-300 */

  --clr-bg-light: #f0fdfa;
  /* Very light teal background */
  --clr-text-light: #064e3b;
  /* Dark teal text */

  --shadow-light: rgba(13, 148, 136, 0.3);
}

[data-theme="light"] {
  --clr-bg: var(--clr-bg-light);
  --clr-text: var(--clr-text-light);
  --shadow: var(--shadow-light);
  --btn-bg: white;
  --btn-text: var(--clr-primary);
  --btn-hover-bg: var(--clr-accent);
  --btn-hover-text: white;
  --section-bg: white;

  /* Landing gradient colors */
  --landing-gradient-start: #0d9488;
  --landing-gradient-middle: #2563eb;
  --landing-gradient-end: #3b82f6;
  --landing-text-color: #e0f7f5;
  /* Light but clear */
  --tagline-color: #c5f3ee;
  /* lighter, more visible */
}

/* Dark Mode Colors */
[data-theme="dark"] {
  --clr-primary: #5eead4;
  /* Muted teal */
  --clr-primary-light: #99f6e4;
  --clr-primary-dark: #2dd4bf;

  --clr-accent: #60a5fa;
  --clr-accent-light: #93c5fd;

  --clr-bg: #1e293b;
  /* Dark slate gray – softer on the eyes */
  --clr-text: #e2e8f0;
  /* Light gray for easy reading */

  --shadow: rgba(136, 232, 222, 0.1);
  --btn-bg: #334155;
  /* Muted blue-gray button */
  --btn-text: #e2e8f0;
  --btn-hover-bg: #475569;
  --btn-hover-text: white;

  --section-bg: #273549;
  /* Lighter than bg, enough contrast */

  /* Landing gradient */
  --landing-gradient-start: #334155;
  --landing-gradient-middle: #3b82f6;
  --landing-gradient-end: #60a5fa;

  --landing-text-color: #f1f5f9;
  --tagline-color: #bae6fd;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  background-color: var(--clr-bg);
  color: var(--clr-text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
  scroll-behavior: smooth;
  transition: background-color 0.5s ease, color 0.5s ease;
}

a {
  color: var(--clr-primary);
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover,
a:focus {
  color: var(--clr-primary-dark);
  outline: none;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

h1,
h2,
h3 {
  margin: 0;
  font-weight: 600;
  letter-spacing: 0.04em;
}

h1 {
  font-size: 3.8rem;
  line-height: 1.1;
  margin-bottom: 0.3rem;
  color: var(--landing-text-color);
  text-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

h2 {
  font-size: 2.4rem;
  margin-bottom: 1rem;
  color: var(--clr-primary-dark);
}

h3 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
  color: var(--clr-primary);
}

p {
  font-weight: 300;
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto 1.8rem auto;
  color: var(--clr-text);
}

/* === Landing Section === */
#landing {
  height: 100vh;
  background: linear-gradient(135deg,
      var(--landing-gradient-start),
      var(--landing-gradient-middle),
      var(--landing-gradient-end));
  color: var(--landing-text-color);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 0 1rem;
  position: relative;
  overflow: hidden;
  transition: background 0.5s ease, color 0.5s ease;
  scroll-margin-top: 0;
}

/* Animated subtle glowing shapes behind text */
#landing::before,
#landing::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(150px);
  opacity: 0.5;
  animation: float 10s ease-in-out infinite alternate;
  z-index: 0;
}

#landing::before {
  width: 400px;
  height: 400px;
  background: rgba(37, 99, 235, 0.6);
  /* blue */
  top: 10%;
  left: 15%;
  animation-delay: 0s;
}

#landing::after {
  width: 300px;
  height: 300px;
  background: rgba(59, 130, 246, 0.6);
  /* lighter blue */
  bottom: 15%;
  right: 20%;
  animation-delay: 5s;
}

@keyframes float {
  0% {
    transform: translateY(0) translateX(0);
    opacity: 0.5;
  }

  100% {
    transform: translateY(-20px) translateX(15px);
    opacity: 0.7;
  }
}

.tagline {
  font-weight: 400;
  font-size: 1.8rem;
  margin-bottom: 2.8rem;
  letter-spacing: 0.1em;
  text-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
  position: relative;
  z-index: 1;
  color: var(--tagline-color);
}

/* === Buttons === */

/* Explore Button */
.btn-explore {
  font-weight: 600;
  font-size: 1rem;
  /* smaller and more refined */
  padding: 0.5rem 1.8rem;
  border-radius: 9999px;
  /* pill shape */
  background: transparent;
  color: var(--landing-text-color);
  border: 2px solid var(--landing-text-color);
  cursor: pointer;
  transition:
    color 0.3s ease,
    background-color 0.3s ease,
    transform 0.2s ease,
    box-shadow 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  max-width: 220px;
  width: 100%;
  user-select: none;
  box-shadow: none;
  position: relative;
  z-index: 1;
}

.btn-explore::after {
  content: '→';
  font-weight: 600;
  font-size: 1.2rem;
  transition: transform 0.3s ease;
}

.btn-explore:hover,
.btn-explore:focus {
  background-color: var(--landing-text-color);
  color: var(--landing-gradient-start);
  transform: scale(1.05);
  outline: none;
  box-shadow: 0 6px 15px rgba(37, 99, 235, 0.3);
}

.btn-explore:hover::after,
.btn-explore:focus::after {
  transform: translateX(4px);
}

/* Dark mode Explore button overrides */
[data-theme="dark"] .btn-explore {
  color: var(--landing-text-color);
  border-color: var(--landing-text-color);
  box-shadow: 0 6px 18px rgba(94, 234, 212, 0.5);
  background-color: var(--btn-bg);
  transition: background-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}

[data-theme="dark"] .btn-explore:hover,
[data-theme="dark"] .btn-explore:focus {
  background-color: var(--landing-text-color);
  color: var(--landing-gradient-start);
  box-shadow: 0 8px 25px rgba(94, 234, 212, 0.8);
  outline: none;
}

/* === Sections === */
#about {
  background-color: var(--section-bg);
  border-radius: 20px;
  padding: 3.5rem 2rem;
  margin-top: 6rem;
  box-shadow: 0 10px 30px var(--shadow);
  position: relative;
  max-width: 840px;
  margin-left: auto;
  margin-right: auto;
  transition: background-color 0.5s ease, color 0.5s ease;
}

#about p {
  color: var(--clr-text);
  font-weight: 400;
  font-size: 1.3rem;
  line-height: 1.75;
  margin-bottom: 0;
}

#app-section {
  max-width: 840px;
  margin: 3rem auto 0 auto;
  padding: 3rem 2rem;
  border-radius: 20px;
  background-color: var(--section-bg);
  box-shadow: 0 10px 30px var(--shadow);
  transition: background-color 0.5s ease, color 0.5s ease;
}

#app-section h3 {
  margin-top: 0;
  margin-bottom: 1rem;
  color: var(--clr-primary);
  font-weight: 600;
  font-size: 2rem;
}

#app-section p.lead {
  font-weight: 400;
  font-size: 1.2rem;
  color: var(--clr-text);
  margin-bottom: 1.5rem;
}

#app-section ul {
  list-style: none;
  padding-left: 0;
  color: var(--clr-text);
}

#app-section ul li {
  margin-bottom: 0.8rem;
  padding-left: 1.3rem;
  position: relative;
}

#app-section ul li::before {
  content: '✔';
  position: absolute;
  left: 0;
  color: var(--clr-primary);
  font-weight: 600;
}

/* Footer */
footer {
  text-align: center;
  padding: 1rem;
  font-size: 0.9rem;
  color: var(--clr-text);
  background-color: var(--section-bg);
  border-top: 1px solid rgba(0, 0, 0, 0.05);
  transition: background-color 0.5s ease, color 0.5s ease;
  user-select: none;
  margin-top: 5rem;
}

/* Dark mode adjustments for About & App sections */
[data-theme="dark"] #about,
[data-theme="dark"] #app-section {
  border: 1px solid rgba(255 255 255 / 0.15);
  background-color: #273549;
  /* keep your current bg */
  border-radius: 20px;
  box-shadow: 0 10px 30px var(--shadow);
  transition: background-color 0.5s ease, color 0.5s ease, border-color 0.5s ease;
}

/* Dark mode toggle switch button */
.toggle-theme-switch {
  position: fixed;
  top: 1.25rem;
  right: 1.25rem;
  width: 50px;
  height: 26px;
  background-color: var(--btn-bg);
  border-radius: 13px;
  border: 2px solid var(--clr-primary);
  cursor: pointer;
  box-shadow: 0 2px 10px var(--shadow);
  transition: background-color 0.3s ease, border-color 0.3s ease;
  display: flex;
  align-items: center;
  padding: 2px;
  z-index: 10;
  user-select: none;
}

.switch-thumb {
  display: block;
  width: 22px;
  height: 22px;
  background-color: var(--clr-primary);
  border-radius: 50%;
  transition: transform 0.3s ease, background-color 0.3s ease;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

/* Dark mode active styles */
[data-theme="dark"] .toggle-theme-switch {
  background-color: var(--btn-bg);
  border-color: var(--clr-primary-light);
}

[data-theme="dark"] .switch-thumb {
  background-color: var(--clr-primary-light);
  transform: translateX(24px);
}

/* Buttons (general) */
button,
input[type="submit"],
input[type="button"],
input[type="reset"] {
  cursor: pointer;
  border-radius: 9999px;
  border: none;
  padding: 0.6rem 1.4rem;
  font-weight: 600;
  font-size: 1rem;
  transition:
    background-color 0.3s ease,
    color 0.3s ease,
    box-shadow 0.3s ease;
}

/* Reduce motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001s !important;
    transition-duration: 0.001s !important;
    scroll-behavior: auto !important;
  }
}

.btn-coming-soon {
  color: var(--clr-primary-dark);
  /* darker teal text */
  border: 2px solid var(--clr-primary);
  /* clear border */
  padding: 0.3em 0.8em;
  border-radius: 8px;
  font-weight: 600;
  display: inline-block;
  cursor: not-allowed;
  /* show disabled cursor */
  user-select: none;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
  background-color: transparent;
}

/* Highlight on normal (non-hover) state */
.btn-coming-soon:hover,
.btn-coming-soon:focus {
  background-color: var(--clr-primary-light);
  /* subtle highlight */
  color: white;
  border-color: var(--clr-primary-light);
  cursor: not-allowed;
  /* keep disabled cursor */
  /* disable pointer events to prevent hover effects */
  pointer-events: none;
  opacity: 0.7;
  /* slightly dim on hover */
}

/* === Accessibility: Focus-visible styles for keyboard navigation === */
button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--clr-accent);
  outline-offset: 2px;
}