/* ============================================
   yNote Introduction Site - Main Stylesheet
   ============================================ */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  color: #333;
  background-color: #f9fbf9;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: #4caf50;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #388e3c;
}

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

ul,
ol {
  list-style: none;
}

/* --- Utility --- */
.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: #2e7d32;
  text-align: center;
  margin-bottom: 48px;
}

.section-title::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background-color: #81c784;
  border-radius: 2px;
  margin: 12px auto 0;
}

/* --- Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #e0e0e0;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.site-logo {
  display: flex;
  align-items: center;
}

.site-logo-img {
  height: 32px;
  width: auto;
}

.global-nav-list {
  display: flex;
  gap: 32px;
}

.global-nav-list a {
  color: #555;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 4px 0;
  position: relative;
  transition: color 0.2s ease;
}

.global-nav-list a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: #66bb6a;
  border-radius: 1px;
  transition: width 0.25s ease;
}

.global-nav-list a:hover,
.global-nav-list a.active {
  color: #2e7d32;
}

.global-nav-list a:hover::after,
.global-nav-list a.active::after {
  width: 100%;
}

/* Hamburger Button */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #555;
  border-radius: 1px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.open span:nth-child(2) {
  opacity: 0;
}

.hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- Hero Section --- */
.hero {
  background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 50%, #a5d6a7 100%);
  padding: 100px 0 80px;
  text-align: center;
}

.hero-catch {
  font-size: 2.5rem;
  font-weight: 700;
  color: #1b5e20;
  margin-bottom: 16px;
  line-height: 1.4;
}

.hero-sub {
  font-size: 1.15rem;
  color: #4a7c4f;
  margin-bottom: 40px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.btn-primary {
  background-color: #4caf50;
  color: #fff;
}

.btn-primary:hover {
  background-color: #43a047;
  color: #fff;
}

.btn-secondary {
  background-color: #fff;
  color: #4caf50;
  border: 2px solid #4caf50;
}

.btn-secondary:hover {
  background-color: #e8f5e9;
  color: #388e3c;
}

/* --- Feature Cards --- */
.features {
  background-color: #fff;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.feature-card {
  background-color: #f9fbf9;
  border: 1px solid #e8f0e8;
  border-radius: 16px;
  padding: 36px 28px;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(76, 175, 80, 0.1);
}

.feature-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  background-color: #e8f5e9;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #2e7d32;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.925rem;
  color: #666;
  line-height: 1.7;
}

/* --- CTA Section --- */
.cta-section {
  background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
  text-align: center;
}

.cta-section .section-title {
  margin-bottom: 16px;
}

.cta-section .section-title::after {
  display: none;
}

.cta-description {
  font-size: 1.05rem;
  color: #4a7c4f;
  margin-bottom: 32px;
}

/* --- Guide Page --- */
.guide-nav {
  background-color: #fff;
  border-bottom: 1px solid #e0e0e0;
  padding: 16px 0;
  position: sticky;
  top: 64px;
  z-index: 900;
}

.guide-nav-list {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}

.guide-nav-list a {
  display: inline-block;
  padding: 8px 18px;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  color: #555;
  background-color: #f5f5f5;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.guide-nav-list a:hover,
.guide-nav-list a.active {
  background-color: #4caf50;
  color: #fff;
}

.guide-section {
  padding: 64px 0;
  border-bottom: 1px solid #eee;
}

.guide-section:last-child {
  border-bottom: none;
}

.guide-section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: #2e7d32;
  margin-bottom: 20px;
  padding-left: 16px;
  border-left: 4px solid #66bb6a;
}

.guide-section-text {
  font-size: 1rem;
  color: #555;
  line-height: 1.8;
  margin-bottom: 32px;
}

/* Screenshot Placeholder */
.screenshot-placeholder {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  aspect-ratio: 16 / 10;
  background-color: #e8f5e9;
  border: 2px dashed #a5d6a7;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #81c784;
  font-size: 0.95rem;
  font-weight: 500;
}

/* --- Contact Page --- */
.contact-section {
  text-align: center;
  min-height: 50vh;
  display: flex;
  align-items: center;
}

.contact-inner {
  max-width: 600px;
  margin: 0 auto;
}

.contact-text {
  font-size: 1.05rem;
  color: #555;
  line-height: 1.8;
  margin-bottom: 40px;
}

/* --- Footer --- */
.site-footer {
  background-color: #2e7d32;
  color: rgba(255, 255, 255, 0.8);
  text-align: center;
  padding: 24px 0;
  font-size: 0.85rem;
}