/* ============================================
   Vocabnote LP - Common Stylesheet
   Dark theme, Apple-inspired minimal design
   ============================================ */

:root {
  --bg: #000000;
  --bg-elev-1: #0a0a0a;
  --bg-elev-2: #141414;
  --bg-elev-3: #1c1c1e;
  --text: #f5f5f7;
  --text-secondary: #a1a1a6;
  --text-tertiary: #6e6e73;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --accent: #60a5fa;
  --accent-light: #93c5fd;
  --accent-deep: #3b82f6;
  --accent-gradient: linear-gradient(135deg, #93c5fd 0%, #60a5fa 50%, #3b82f6 100%);
  --shadow-glow: 0 0 80px rgba(96, 165, 250, 0.15);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;
  --max-width: 1120px;
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic",
    "Meiryo", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition);
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== Layout ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .container {
    padding: 0 48px;
  }
}

/* ===== Header / Nav ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.nav-brand img {
  width: 26px;
  height: 26px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 400;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-lang {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 6px 12px;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  transition: var(--transition);
}

.nav-lang:hover {
  border-color: var(--accent);
  color: var(--text);
}

@media (max-width: 640px) {
  .nav-links {
    gap: 14px;
  }
  .nav-links .hide-mobile {
    display: none;
  }
}

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 80px 0 60px;
  text-align: center;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(
    circle,
    rgba(96, 165, 250, 0.18) 0%,
    rgba(96, 165, 250, 0) 60%
  );
  pointer-events: none;
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-logo {
  width: 150px;
  height: 150px;
  margin: 0 auto 28px;
  filter: drop-shadow(0 8px 32px rgba(96, 165, 250, 0.4));
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.hero-title {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 20px;
  background: linear-gradient(180deg, #ffffff 0%, #c0c0c8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-tagline {
  font-size: clamp(18px, 2.4vw, 24px);
  font-weight: 400;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 40px;
  line-height: 1.5;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 500;
  letter-spacing: -0.01em;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 8px 24px rgba(96, 165, 250, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(96, 165, 250, 0.45);
  color: #ffffff;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  border: 1px solid var(--border-strong);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  color: var(--text);
}

/* App Store Badge */
.app-store-badge {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 12px 24px;
  background: #ffffff;
  color: #000000;
  border-radius: 14px;
  font-weight: 500;
  transition: var(--transition);
}

.app-store-badge:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(255, 255, 255, 0.15);
  color: #000000;
}

.app-store-badge .apple-icon {
  width: 28px;
  height: 28px;
}

.app-store-badge .label-small {
  font-size: 11px;
  color: #6e6e73;
  display: block;
  line-height: 1.2;
}

.app-store-badge .label-large {
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

/* ===== Hero Visual ===== */
.hero-visual {
  position: relative;
  margin: 0 auto;
  max-width: 880px;
  padding: 0 20px;
}

.hero-visual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: center;
}

@media (max-width: 768px) {
  .hero-visual-grid {
    grid-template-columns: 1fr;
    max-width: 360px;
    margin: 0 auto;
  }
}

.device-frame {
  position: relative;
  border-radius: 36px;
  padding: 8px;
  background: linear-gradient(160deg, #2a2a2c 0%, #0a0a0a 100%);
  box-shadow: var(--shadow-glow), 0 30px 60px rgba(0, 0, 0, 0.6);
}

.device-frame img {
  border-radius: 28px;
  width: 100%;
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
  position: relative;
}

.section-sm {
  padding: 60px 0;
}

.section-title {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  text-align: center;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: clamp(16px, 2vw, 19px);
  color: var(--text-secondary);
  text-align: center;
  max-width: 640px;
  margin: 0 auto 60px;
  line-height: 1.5;
}

/* ===== Features Grid ===== */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 40px;
}

.feature-card {
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  position: relative;
  overflow: hidden;
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 24px;
}

.feature-icon.icon-blue { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.feature-icon.icon-purple { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.feature-icon.icon-green { background: rgba(34, 197, 94, 0.15); color: #4ade80; }
.feature-icon.icon-orange { background: rgba(249, 115, 22, 0.15); color: #fb923c; }
.feature-icon.icon-pink { background: rgba(236, 72, 153, 0.15); color: #f472b6; }

.feature-title {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
  color: var(--text);
}

.feature-desc {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== iCloud Section ===== */
.icloud-section {
  background: var(--bg-elev-1);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

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

@media (max-width: 768px) {
  .icloud-grid {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }
}

.icloud-text h2 {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 20px;
}

.icloud-text p {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.icloud-visual {
  display: flex;
  justify-content: center;
}

.icloud-visual img {
  max-width: 200px;
  filter: drop-shadow(0 8px 40px rgba(96, 165, 250, 0.3));
}

/* ===== Languages ===== */
.languages {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  max-width: 720px;
  margin: 0 auto;
}

.lang-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 15px;
  color: var(--text);
}

.lang-chip .flag {
  font-size: 18px;
}

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

.cta-section h2 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 24px;
}

.cta-section p {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  background: var(--bg-elev-1);
}

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

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--text);
}

.footer-brand img {
  width: 24px;
  height: 24px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  justify-content: center;
  list-style: none;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 14px;
}

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

.footer-copyright {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ===== Document pages (privacy / contact) ===== */
.doc-page {
  max-width: 760px;
  margin: 0 auto;
  padding: 80px 24px 100px;
}

.doc-page h1 {
  font-size: clamp(32px, 5vw, 44px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 12px;
}

.doc-meta {
  color: var(--text-tertiary);
  font-size: 14px;
  margin-bottom: 48px;
}

.doc-page h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-top: 40px;
  margin-bottom: 14px;
  color: var(--text);
}

.doc-page h3 {
  font-size: 17px;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
  color: var(--text);
}

.doc-page p,
.doc-page li {
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.75;
  margin-bottom: 14px;
}

.doc-page ul {
  padding-left: 22px;
  margin-bottom: 14px;
}

.doc-page a {
  color: var(--accent);
  word-break: break-word;
}

.doc-page hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

/* ===== Contact form embed ===== */
.form-wrap {
  margin-top: 32px;
  background: var(--bg-elev-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.form-wrap iframe {
  width: 100%;
  min-height: 750px;
  border: 0;
  display: block;
  background: #ffffff;
}

.contact-note {
  margin-top: 24px;
  padding: 18px 22px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

/* ===== Utility ===== */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }

/* ===== Scroll reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Reduced motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .hero-logo {
    animation: none;
  }
}