/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --black: #000;
  --white: #fff;
  --gray-50: #fafafa;
  --gray-100: #f5f5f5;
  --gray-200: #e5e5e5;
  --gray-400: #a3a3a3;
  --gray-500: #737373;
  --gray-600: #525252;
  --gray-900: #171717;
  --blue: #4f5bd5;
  --blue-light: #ddd6fe;
  --purple: #7c5cfc;
  --accent: #4f5bd5;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--white);
  color: var(--gray-900);
  line-height: 1.5;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Nav */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--gray-200);
}

.nav-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--black);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.logo-dot {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  background: #e6e6e6;
  display: inline-block;
  position: relative;
}

.logo-dot::after {
  content: '';
  width: 16px;
  height: 16px;
  background: #d9d9d9;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: inset 0 1px 4px rgba(0,0,0,0.08);
}

.logo-dot-sm {
  width: 22px;
  height: 22px;
  border-radius: 6px;
}

.logo-dot-sm::after {
  width: 13px;
  height: 13px;
}

.nav-download {
  padding: 8px 20px;
  background: var(--black);
  color: var(--white);
  border-radius: 980px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s;
}

.nav-download:hover {
  opacity: 0.85;
}

/* Hero */
.hero {
  max-width: 680px;
  margin: 0 auto;
  padding: 120px 24px 48px;
  text-align: center;
}

.hero-title {
  font-size: clamp(72px, 15vw, 120px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 0.9;
}

.hero-sub {
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 500;
  color: var(--gray-600);
  margin-top: 8px;
  letter-spacing: -0.02em;
}

.hero-desc {
  font-size: 18px;
  color: var(--gray-500);
  max-width: 440px;
  margin: 20px auto 28px;
  line-height: 1.6;
}

.app-store-badge {
  display: inline-block;
  transition: opacity 0.2s;
}

.app-store-badge:hover {
  opacity: 0.8;
}

/* Chat Demo */
.hero-chat {
  max-width: 420px;
  margin: 40px auto 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.chat-bubble {
  padding: 16px 20px;
  border-radius: 20px;
  font-size: 17px;
  line-height: 1.45;
  max-width: 85%;
  text-align: left;
}

.chat-user {
  background: #007AFF;
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 6px;
}

.chat-ai {
  background: var(--gray-100);
  color: var(--gray-900);
  align-self: flex-start;
  border-bottom-left-radius: 6px;
  border: 1px solid var(--gray-200);
}

/* Feature Sections */
.feature {
  max-width: 680px;
  margin: 0 auto;
  padding: 56px 24px;
  text-align: center;
}

.feature-text h2 {
  font-size: clamp(48px, 10vw, 72px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 0.95;
}

.feature-text p {
  font-size: clamp(17px, 3vw, 20px);
  color: var(--gray-500);
  margin-top: 12px;
  line-height: 1.5;
}

/* App Icons Grid */
.app-icons-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  max-width: 360px;
  margin: 40px auto 0;
}

.app-icon {
  width: 100px;
  height: 100px;
  border-radius: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  justify-self: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

.app-icon svg {
  width: 40px;
  height: 40px;
}

.app-icon:hover {
  transform: scale(1.08);
}

/* Skill Card */
.skill-card {
  max-width: 420px;
  margin: 40px auto 0;
  background: var(--white);
  border-radius: 20px;
  padding: 24px;
  text-align: left;
  box-shadow: 0 2px 24px rgba(0,0,0,0.08), 0 0 0 1px var(--gray-200);
}

.skill-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.skill-icon {
  width: 44px;
  height: 44px;
  background: #fff3e0;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.skill-title {
  font-size: 16px;
  font-weight: 700;
}

.skill-sub {
  font-size: 13px;
  color: var(--gray-500);
}

.skill-detail {
  margin-bottom: 14px;
}

.skill-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--gray-500);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 3px;
}

.skill-value {
  font-size: 15px;
  color: var(--gray-900);
  line-height: 1.4;
}

.skill-actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.skill-btn {
  flex: 1;
  padding: 12px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  font-family: inherit;
  transition: opacity 0.2s;
}

.skill-btn:hover {
  opacity: 0.85;
}

.skill-btn-cancel {
  background: var(--gray-100);
  color: var(--gray-900);
}

.skill-btn-add {
  background: #007AFF;
  color: white;
}

/* Memories Card */
.memories-card {
  max-width: 420px;
  margin: 40px auto 0;
  background: var(--white);
  border-radius: 20px;
  padding: 24px;
  text-align: left;
  box-shadow: 0 2px 24px rgba(0,0,0,0.08), 0 0 0 1px var(--gray-200);
}

.memory-section-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-500);
  margin-bottom: 8px;
  margin-top: 12px;
}

.memory-section-label:first-child {
  margin-top: 0;
}

.memory-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--gray-100);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.memory-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.memory-text {
  font-size: 15px;
  line-height: 1.4;
  color: var(--gray-900);
}

.memory-tag {
  font-size: 12px;
  color: var(--gray-400);
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 3px;
  background: var(--gray-100);
  padding: 3px 8px;
  border-radius: 6px;
}

.memory-tag::before {
  content: '\2728';
  font-size: 10px;
}

/* History Card */
.history-card {
  max-width: 420px;
  margin: 40px auto 0;
  background: var(--white);
  border-radius: 20px;
  padding: 8px 24px;
  text-align: left;
  box-shadow: 0 2px 24px rgba(0,0,0,0.08), 0 0 0 1px var(--gray-200);
}

.history-item {
  padding: 16px 0;
  border-bottom: 1px solid var(--gray-100);
}

.history-item:last-child {
  border-bottom: none;
}

.history-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--gray-900);
}

.history-meta {
  font-size: 13px;
  color: var(--gray-400);
  margin-top: 2px;
}

.history-preview {
  font-size: 14px;
  color: var(--gray-500);
  margin-top: 4px;
  line-height: 1.45;
}

/* CTA */
.cta {
  max-width: 680px;
  margin: 0 auto;
  padding: 56px 24px 100px;
  text-align: center;
}

.cta h2 {
  font-size: clamp(44px, 10vw, 68px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 0.95;
}

.cta p {
  font-size: 18px;
  color: var(--gray-500);
  margin: 16px 0 28px;
}

/* Footer */
.footer {
  border-top: 1px solid var(--gray-200);
  padding: 32px 24px;
}

.footer-inner {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--gray-900);
}

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

.footer-links a {
  font-size: 14px;
  color: var(--gray-500);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--gray-900);
}

.footer-copy {
  font-size: 13px;
  color: var(--gray-400);
  width: 100%;
  text-align: center;
  margin-top: 4px;
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 640px) {
  .hero {
    padding: 110px 20px 40px;
  }

  .feature {
    padding: 48px 20px;
  }

  .app-icons-grid {
    max-width: 280px;
    gap: 12px;
  }

  .app-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
  }

  .app-icon svg {
    width: 32px;
    height: 32px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .cta {
    padding: 48px 20px 72px;
  }
}