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

:root {
  --green: #2c4a2e;
  --green-light: #3a5e3c;
  --dark: #1a1a1a;
  --gray: #666;
  --light-gray: #f5f4f0;
  --border: #ddd;
  --white: #fff;
  --error: #c0392b;
  --success: #27ae60;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
  color: var(--dark);
  background: var(--white);
  font-size: 14px;
  line-height: 1.7;
}

a { text-decoration: none; color: inherit; }

/* ========== HEADER ========== */
header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  height: 64px;
  border-bottom: 1px solid rgba(0,0,0,0.06);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-text { line-height: 1.2; }
.logo-text strong { font-size: 15px; font-weight: 700; letter-spacing: 0.08em; color: var(--dark); }
.logo-text span { font-size: 9px; color: var(--gray); letter-spacing: 0.06em; display: block; }

nav { display: flex; gap: 32px; }
nav a {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--dark);
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s;
}
nav a:hover, nav a.active { border-bottom-color: var(--green); }

/* ========== PAGE HEADER ========== */
.page-header {
  padding-top: 64px;
  background: var(--light-gray);
  text-align: center;
  padding-bottom: 64px;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: 'CONTACT';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: clamp(60px, 12vw, 120px);
  font-weight: 800;
  letter-spacing: 0.15em;
  color: rgba(0,0,0,0.04);
  white-space: nowrap;
  pointer-events: none;
}

.page-header-inner {
  position: relative;
  padding: 60px 0 0;
}

.section-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--gray);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.section-label::before,
.section-label::after {
  content: '';
  display: block;
  width: 32px;
  height: 2px;
  background: var(--dark);
}

.page-header h1 {
  font-size: clamp(24px, 3vw, 38px);
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: 16px;
}

.page-header p {
  font-size: 13px;
  color: var(--gray);
  line-height: 1.9;
}

/* ========== CONTACT SECTION ========== */
.contact-section {
  max-width: 780px;
  margin: 0 auto;
  padding: 80px 40px 120px;
}

/* ========== FORM ========== */
.form-group {
  margin-bottom: 32px;
}

.form-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}

.required {
  font-size: 10px;
  background: var(--green);
  color: var(--white);
  padding: 2px 6px;
  letter-spacing: 0.03em;
}

.optional {
  font-size: 10px;
  background: #ccc;
  color: var(--white);
  padding: 2px 6px;
  letter-spacing: 0.03em;
}

.form-control {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--border);
  background: var(--white);
  font-size: 14px;
  font-family: inherit;
  color: var(--dark);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  border-radius: 0;
  appearance: none;
}

.form-control:focus {
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(44,74,46,0.08);
}

.form-control::placeholder { color: #bbb; }

textarea.form-control {
  min-height: 200px;
  resize: vertical;
  line-height: 1.8;
}

select.form-control {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23666' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
  cursor: pointer;
}

/* ========== PRIVACY ========== */
.privacy-check {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 24px;
  background: var(--light-gray);
  margin-bottom: 40px;
}

.privacy-check input[type="checkbox"] {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  margin-top: 2px;
  accent-color: var(--green);
  cursor: pointer;
}

.privacy-check label {
  font-size: 12px;
  color: var(--gray);
  line-height: 1.8;
  cursor: pointer;
}

.privacy-check a {
  color: var(--green);
  border-bottom: 1px solid var(--green);
}

/* ========== SUBMIT ========== */
.submit-wrap { text-align: center; }

.btn-submit {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: var(--green);
  color: var(--white);
  padding: 16px 56px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  border: none;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  font-family: inherit;
}

.btn-submit:hover { background: var(--green-light); }
.btn-submit:active { transform: scale(0.98); }
.btn-submit:disabled { opacity: 0.5; cursor: not-allowed; }

/* ========== DIVIDER ========== */
.form-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 48px 0;
}

/* ========== SUCCESS / ERROR MESSAGES ========== */
.alert {
  padding: 20px 24px;
  margin-bottom: 32px;
  font-size: 13px;
  line-height: 1.8;
  display: none;
}

.alert.alert-success {
  background: #eafaf1;
  border-left: 4px solid var(--success);
  color: #1e8449;
}

.alert.alert-error {
  background: #fdf2f1;
  border-left: 4px solid var(--error);
  color: var(--error);
}

.alert.show { display: block; }

/* ========== INFO BOX ========== */
.info-box {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  margin-bottom: 64px;
}

.info-item {
  background: var(--white);
  padding: 32px 24px;
  text-align: center;
}

.info-icon {
  width: 40px;
  height: 40px;
  margin: 0 auto 16px;
  color: var(--green);
}

.info-item h3 {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.info-item p {
  font-size: 12px;
  color: var(--gray);
  line-height: 1.7;
}

/* ========== FOOTER ========== */
footer {
  background: #111;
  color: var(--white);
  padding: 48px 80px;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
}

.footer-logo strong { color: var(--white); }
.footer-logo span { color: #666; }

.footer-nav { display: flex; gap: 24px; }
.footer-nav a {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: #888;
  font-weight: 600;
  transition: color 0.2s;
}
.footer-nav a:hover { color: var(--white); }

.footer-social { display: flex; gap: 16px; }
.footer-social a {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid #333;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #888;
  transition: all 0.2s;
}
.footer-social a:hover { border-color: #666; color: var(--white); }
.footer-social svg { width: 14px; height: 14px; }

.footer-copy {
  text-align: center;
  font-size: 11px;
  color: #555;
  letter-spacing: 0.05em;
  padding-top: 24px;
  border-top: 1px solid #222;
}

/* ========== BACK TO TOP ========== */
#back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--dark);
  color: var(--white);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s, background 0.2s;
  z-index: 99;
}
#back-to-top.visible { opacity: 1; pointer-events: auto; }
#back-to-top:hover { background: var(--green); }
#back-to-top svg { width: 16px; height: 16px; }

/* ========== HAMBURGER ========== */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 101;
}
.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--dark);
  transition: transform 0.3s, opacity 0.3s;
}
.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); }

.mobile-menu {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--white);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  flex-direction: column;
  padding: 16px 0;
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  display: block;
  padding: 14px 24px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--dark);
  border-bottom: 1px solid var(--light-gray);
}
.mobile-menu a:last-child { border-bottom: none; }
.mobile-menu a:hover { background: var(--light-gray); }

.mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 99;
}
.mobile-overlay.open { display: block; }

/* ========== RESPONSIVE ========== */
@media (max-width: 900px) {
  header { padding: 0 24px; }
  nav { gap: 16px; }
  nav a { font-size: 11px; }
  .contact-section { padding: 60px 24px 80px; }
  .info-box { grid-template-columns: 1fr; }
  footer { padding: 40px 24px; }
  .footer-inner { flex-direction: column; gap: 24px; text-align: center; }
  .footer-nav { flex-wrap: wrap; justify-content: center; }
}

@media (max-width: 600px) {
  nav { display: none; }
  .hamburger { display: flex; }
}