/* ===== CSS Variables ===== */
:root {
  --primary-gradient: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  --accent-color: #00d9ff;
  --accent-secondary: #ff6b6b;
  --accent-gold: #ffd700;
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --card-bg: rgba(255, 255, 255, 0.05);
  --card-border: rgba(255, 255, 255, 0.1);
  --shadow-glow: 0 0 40px rgba(0, 217, 255, 0.3);
}

/* ===== Base Styles ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--primary-gradient);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

/* ===== Animated Background ===== */
.background-animation {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.floating-note {
  position: absolute;
  font-size: 2rem;
  opacity: 0.1;
  animation: float 15s ease-in-out infinite;
}

.floating-note:nth-child(1) {
  left: 10%;
  animation-delay: 0s;
}

.floating-note:nth-child(2) {
  left: 25%;
  animation-delay: 2s;
}

.floating-note:nth-child(3) {
  left: 40%;
  animation-delay: 4s;
}

.floating-note:nth-child(4) {
  left: 55%;
  animation-delay: 6s;
}

.floating-note:nth-child(5) {
  left: 70%;
  animation-delay: 8s;
}

.floating-note:nth-child(6) {
  left: 85%;
  animation-delay: 10s;
}

@keyframes float {

  0%,
  100% {
    transform: translateY(100vh) rotate(0deg);
    opacity: 0;
  }

  10% {
    opacity: 0.15;
  }

  90% {
    opacity: 0.15;
  }

  100% {
    transform: translateY(-100px) rotate(360deg);
    opacity: 0;
  }
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* ===== Header / Navigation ===== */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px 0;
  background: rgba(26, 26, 46, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--card-border);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text-primary);
}

.logo-icon {
  font-size: 2rem;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 32px;
}

nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

nav a:hover {
  color: var(--accent-color);
}

/* ===== Hero Section ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 100px;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-text h1 {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  background: linear-gradient(135deg, #ffffff 0%, var(--accent-color) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text .subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 500px;
}

.cta-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 16px 32px;
  background: linear-gradient(135deg, var(--accent-color) 0%, #0099cc 100%);
  color: #000;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  border-radius: 50px;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 40px rgba(0, 217, 255, 0.5);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 16px 32px;
  background: transparent;
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid var(--card-border);
  border-radius: 50px;
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  border-color: var(--accent-color);
  background: rgba(0, 217, 255, 0.1);
}

.hero-image {
  position: relative;
  display: flex;
  justify-content: center;
}

.phone-mockup {
  position: relative;
  width: 560px;
  height: 300px;
  background: #000;
  border-radius: 24px;
  padding: 10px;
  box-shadow:
    0 50px 100px rgba(0, 0, 0, 0.5),
    0 0 60px rgba(0, 217, 255, 0.2);
  animation: phoneFloat 6s ease-in-out infinite;
}

.phone-screen {
  width: 100%;
  height: 100%;
  border-radius: 16px;
  overflow: hidden;
  background: #000;
}

.phone-screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

@keyframes phoneFloat {

  0%,
  100% {
    transform: translateY(0px);
  }

  50% {
    transform: translateY(-20px);
  }
}

.glow-effect {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(0, 217, 255, 0.3) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  z-index: -1;
  animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {

  0%,
  100% {
    transform: translate(-50%, -50%) scale(1);
    opacity: 0.5;
  }

  50% {
    transform: translate(-50%, -50%) scale(1.2);
    opacity: 0.8;
  }
}

/* ===== Features Section ===== */
.features {
  padding: 120px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 80px;
}

.section-header h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 24px;
  padding: 40px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-color) 0%, var(--accent-secondary) 100%);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 217, 255, 0.3);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, rgba(0, 217, 255, 0.2) 0%, rgba(0, 217, 255, 0.05) 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin-bottom: 24px;
}

.feature-card h3 {
  font-size: 1.375rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ===== Modes Section ===== */
.modes {
  padding: 120px 0;
}

.modes-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
}

.mode-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 32px;
  padding: 48px;
  text-align: center;
  transition: all 0.3s ease;
}

.mode-card:hover {
  transform: scale(1.02);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
}

.mode-icon {
  width: 100px;
  height: 100px;
  margin: 0 auto 32px;
  background: linear-gradient(135deg, rgba(0, 217, 255, 0.3) 0%, rgba(0, 217, 255, 0.1) 100%);
  border-radius: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
}

.mode-card.appreciation .mode-icon {
  background: linear-gradient(135deg, rgba(255, 107, 107, 0.3) 0%, rgba(255, 107, 107, 0.1) 100%);
}

.mode-card h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.mode-card p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.8;
}

/* ===== CTA Section ===== */
.cta-section {
  padding: 120px 0;
  text-align: center;
}

.cta-box {
  background: linear-gradient(135deg, rgba(0, 217, 255, 0.1) 0%, rgba(255, 107, 107, 0.1) 100%);
  border: 1px solid var(--card-border);
  border-radius: 40px;
  padding: 80px 48px;
}

.cta-box h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.cta-box p {
  color: var(--text-secondary);
  font-size: 1.25rem;
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.download-badge {
  display: inline-block;
  transition: transform 0.3s ease;
}

.download-badge:hover {
  transform: scale(1.05);
}

.download-badge img {
  height: 60px;
}

/* ===== Footer ===== */
footer {
  padding: 60px 0;
  border-top: 1px solid var(--card-border);
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 600;
}

.footer-logo span:first-child {
  font-size: 1.5rem;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--accent-color);
}

.copyright {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ===== Piano Animation ===== */
.piano-keys {
  display: flex;
  gap: 4px;
  padding: 20px;
  background: linear-gradient(180deg, #2a2a2a 0%, #1a1a1a 100%);
  border-radius: 0 0 12px 12px;
}

.key {
  width: 40px;
  height: 140px;
  background: linear-gradient(180deg, #f5f5f5 0%, #e0e0e0 100%);
  border-radius: 0 0 6px 6px;
  cursor: pointer;
  transition: all 0.1s ease;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.key.black {
  width: 28px;
  height: 90px;
  background: linear-gradient(180deg, #3a3a3a 0%, #1a1a1a 100%);
  margin-left: -16px;
  margin-right: -16px;
  z-index: 1;
}

.key:active,
.key.active {
  background: linear-gradient(180deg, #00d9ff 0%, #0099cc 100%);
  transform: translateY(4px);
}

.key.black:active,
.key.black.active {
  background: linear-gradient(180deg, #0099cc 0%, #006688 100%);
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text .subtitle {
    margin-left: auto;
    margin-right: auto;
  }

  .cta-buttons {
    justify-content: center;
  }

  .hero-image {
    order: -1;
  }

  .phone-mockup {
    width: 480px;
    height: 260px;
  }

  .modes-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }
}

@media (max-width: 768px) {
  .hero-text h1 {
    font-size: 2.5rem;
  }

  .section-header h2 {
    font-size: 2rem;
  }

  nav ul {
    display: none;
  }

  .phone-mockup {
    width: 100%;
    max-width: 400px;
    height: 220px;
  }

  .cta-box {
    padding: 48px 24px;
  }

  .cta-box h2 {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .hero-text h1 {
    font-size: 2rem;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    justify-content: center;
  }

  .feature-card {
    padding: 32px 24px;
  }
}