:root {
  --bg-gradient-1: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  --bg-gradient-2: linear-gradient(320deg, #6c5ce7, #a363d9, #ff7675);
  --text-primary: #22223b;
  --header-bg: rgba(255,255,255,0.92);
  --hero-bg: rgba(255,255,255,0.85);
  --accent-color: #6c5ce7;
  --footer-bg: #2d3436;
  --social-icon: #fff;
  --nav-link-hover: #6c5ce7;
  --nav-link-underline: #6c5ce7;
  --cta-bg: linear-gradient(90deg, #ff6f61 0%, #ffbe76 100%);
  --cta-bg-hover: linear-gradient(90deg, #ffbe76 0%, #ff6f61 100%);
  --cta-shadow: 0 6px 24px rgba(255,111,97,0.13);
  --cta-shadow-hover: 0 10px 30px rgba(255,111,97,0.22);
}

[data-theme="dark"] {
  --bg-gradient-1: linear-gradient(135deg, #232526 0%, #414345 100%);
  --bg-gradient-2: linear-gradient(320deg, #4a00e0, #8e2de2, #ff416c);
  --text-primary: #f8f9fa;
  --header-bg: rgba(30,30,30,0.95);
  --hero-bg: rgba(40,40,40,0.9);
  --accent-color: #9d4edd;
  --footer-bg: #181818;
  --social-icon: #e9ecef;
  --nav-link-hover: #9d4edd;
  --nav-link-underline: #9d4edd;
  --cta-bg: linear-gradient(90deg, #7c3aed 0%, #ff6f61 100%);
  --cta-bg-hover: linear-gradient(90deg, #ff6f61 0%, #7c3aed 100%);
  --cta-shadow: 0 6px 24px rgba(124,58,237,0.13);
  --cta-shadow-hover: 0 10px 30px rgba(124,58,237,0.22);
}

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

body {
  margin: 0;
  font-family: 'Segoe UI', 'Roboto', Arial, sans-serif;
  color: var(--text-primary);
  background: var(--bg-gradient-1);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  transition: background 0.5s, color 0.3s;
}

body::before {
  content: '';
  position: fixed;
  z-index: -1;
  top: 0; left: 0; width: 100vw; height: 100vh;
  background: var(--bg-gradient-2);
  background-size: 200% 200%;
  animation: gradient-flow 15s ease infinite;
  opacity: 0.3;
  pointer-events: none;
}

@keyframes gradient-flow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.header {
  position: fixed;
  top: 0; left: 0; width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem 6vw;
  background: var(--header-bg);
  box-shadow: 0 2px 16px rgba(44,62,80,0.04);
  z-index: 1000;
}

.logo {
  font-size: 1.6rem;
  font-weight: bold;
  color: var(--accent-color);
  letter-spacing: 1px;
  text-decoration: none;
}

.nav {
  display: flex;
  gap: 2rem;
}

.nav-link {
  color: var(--text-primary);
  text-decoration: none;
  font-size: 1.08rem;
  position: relative;
  transition: color 0.3s;
}

.nav-link::after {
  content: '';
  display: block;
  width: 0;
  height: 2px;
  background: var(--nav-link-underline);
  transition: width 0.3s;
  border-radius: 2px;
  margin-top: 3px;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--nav-link-hover);
}

.nav-link:hover::after,
.nav-link:focus::after {
  width: 100%;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 4px;
  padding: 8px;
}

.menu-toggle .bar {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--accent-color);
  margin: 4px 0;
  border-radius: 2px;
  transition: all 0.3s;
}

/* Theme toggle styles */
.theme-toggle {
  position: relative;
  width: 44px;
  height: 32px;
  border: none;
  background: none;
  cursor: pointer;
  margin-left: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  outline: none;
}

.theme-toggle svg {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s, transform 0.3s;
  color: var(--accent-color);
  pointer-events: none;
}

.theme-toggle .sun-icon {
  opacity: 1;
  transform: translate(-50%, -50%) rotate(0deg) scale(1);
}

.theme-toggle .moon-icon {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(80deg) scale(0.7);
}

[data-theme="dark"] .theme-toggle .sun-icon {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(-80deg) scale(0.7);
}

[data-theme="dark"] .theme-toggle .moon-icon {
  opacity: 1;
  transform: translate(-50%, -50%) rotate(0deg) scale(1);
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 90px;
  background: transparent;
}

.hero-content {
  text-align: center;
  background: var(--hero-bg);
  padding: 3rem 2rem;
  border-radius: 24px;
  box-shadow: 0 8px 32px rgba(44,62,80,0.08);
  max-width: 500px;
  margin: auto;
  opacity: 0;
  transform: translateY(40px);
  animation: fadeInUp 1.4s cubic-bezier(.5,1.5,.5,1) 0.2s forwards;
  transition: background 0.5s;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-title {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 1rem;
  letter-spacing: 1px;
  transition: color 0.5s;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-primary);
  margin-bottom: 2rem;
  opacity: 0.85;
  transition: color 0.5s;
}

.cta {
  background: var(--cta-bg);
  color: #fff;
  border: none;
  padding: 1em 2.5em;
  border-radius: 30px;
  font-size: 1.2em;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.22s cubic-bezier(.4,1.4,.7,1), box-shadow 0.22s, background 0.4s;
  box-shadow: var(--cta-shadow);
  outline: none;
}

.cta:hover, .cta:focus {
  transform: scale(1.08) translateY(-2px);
  box-shadow: var(--cta-shadow-hover);
  background: var(--cta-bg-hover);
}

.pulse {
  animation: pulse 2.2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(255,111,97,0.25);}
  70% { box-shadow: 0 0 0 15px rgba(255,111,97,0);}
  100% { box-shadow: 0 0 0 0 rgba(255,111,97,0);}
}

.footer {
  background: var(--footer-bg);
  padding: 3rem 6vw 2rem 6vw;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.2rem;
  margin-top: 3rem;
  color: #fff;
  transition: background 0.5s;
}

.social-container {
  display: flex;
  gap: 1.5rem;
}

.social-link {
  display: inline-block;
  transition: transform 0.3s;
}

.social-link:hover,
.social-link:focus {
  transform: translateY(-4px) scale(1.18) rotate(-6deg);
}

.social-icon {
  width: 32px;
  height: 32px;
  fill: var(--social-icon);
  transition: fill 0.3s;
}

.social-link:hover .social-icon,
.social-link:focus .social-icon {
  fill: #ffbe76;
}

.copyright {
  font-size: 1rem;
  opacity: 0.8;
}

@media (max-width: 900px) {
  .hero-title { font-size: 2.2rem; }
  .hero-content { padding: 2rem 1rem; }
}

@media (max-width: 700px) {
  .header { padding: 1rem 3vw; }
  .footer { padding: 2rem 3vw 1.5rem 3vw; }
}

@media (max-width: 600px) {
  .nav {
    position: fixed;
    top: 65px;
    right: -100vw;
    flex-direction: column;
    background: var(--header-bg);
    width: 70vw;
    max-width: 300px;
    padding: 2rem 1rem;
    box-shadow: -2px 0 16px rgba(44,62,80,0.06);
    transition: right 0.3s;
    z-index: 1001;
  }
  .nav.active {
    right: 0;
  }
  .menu-toggle {
    display: flex;
    z-index: 1002;
  }
  .hero-content {
    padding: 1.3rem 0.5rem;
    max-width: 95vw;
  }
  .footer {
    padding: 1.5rem 2vw 1rem 2vw;
  }
}

@media (max-width: 400px) {
  .hero-title { font-size: 1.3rem; }
  .hero-subtitle { font-size: 0.95rem; }
  .cta { font-size: 1rem; padding: 0.7em 1.5em; }
}