/* ===== Design Tokens ===== */
:root {
  --bg: #0a0a0b; --s1: #111113; --s2: #1a1a1e; --bd: #28282e;
  --text: #e4e2da; --m: #4e4e58; --m2: #6e6e7a;
  --gold: #c8a86a; --gold2: #e6c88a; --gold-bg: rgba(200,168,106,0.08);
  --green: #5db87a; --red: #c0605a;
}
body.theme-light {
  --bg: #fdfaf5; --s1: #fffdfa; --s2: #f5f0e8; --bd: #e8e2d0;
  --text: #3c3836; --m: #a89984; --m2: #928374;
  --gold: #b57614; --gold2: #d79921; --gold-bg: rgba(181,118,20,0.06);
  --green: #427b58; --red: #9d0006;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg); color: var(--text);
  font-family: -apple-system, "Noto Sans SC", "PingFang SC", sans-serif;
  line-height: 1.6; transition: background 0.3s, color 0.3s;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; }
.section-label {
  font-size: 12px; color: var(--gold); letter-spacing: 4px;
  text-transform: uppercase; margin-bottom: 16px;
}
.section-title {
  font-size: 32px; font-weight: 700; line-height: 1.4; margin-bottom: 20px;
}
.section-sub { font-size: 16px; color: var(--m2); line-height: 1.8; }

/* ===== Scroll Reveal ===== */
.reveal {
  opacity: 0; transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }

/* ===== Nav ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 24px; display: flex; align-items: center; justify-content: space-between;
  transition: background 0.3s, border-color 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(10,10,11,0.85); backdrop-filter: blur(12px);
  border-bottom-color: var(--bd);
}
body.theme-light .nav.scrolled { background: rgba(253,250,245,0.85); }
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-brand img { width: 28px; height: 28px; border-radius: 50%; }
.nav-brand span { font-size: 16px; font-weight: 600; color: var(--gold); }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-link {
  font-size: 14px; color: var(--m2); padding: 6px 14px;
  border: 1px solid var(--bd); border-radius: 20px;
  transition: all 0.2s;
}
.nav-link:hover { color: var(--gold); border-color: var(--gold); }
.theme-btn {
  background: none; border: none; cursor: pointer; color: var(--m2);
  font-size: 18px; padding: 4px; transition: color 0.2s;
}
.theme-btn:hover { color: var(--gold); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  position: relative; padding: 80px 24px 60px;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 50% 40%, rgba(200,168,106,0.06) 0%, transparent 70%);
  pointer-events: none;
}
.hero-orb {
  width: 160px; height: 160px; margin-bottom: 40px; position: relative;
  animation: breathe 3s ease-in-out infinite;
}
.hero-orb svg { width: 100%; height: 100%; }
.hero-orb::after {
  content: ''; position: absolute; inset: -40px;
  background: radial-gradient(circle, rgba(200,168,106,0.12) 0%, transparent 70%);
  border-radius: 50%; z-index: -1;
}
@keyframes breathe { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.06); } }

.hero-title { font-size: 56px; font-weight: 800; letter-spacing: 2px; margin-bottom: 8px; }
.hero-subtitle {
  font-size: 16px; color: var(--gold); font-weight: 300;
  letter-spacing: 8px; opacity: 0.6; margin-bottom: 32px;
}
.hero-tagline { font-size: 22px; font-weight: 400; margin-bottom: 12px; }
.hero-desc { font-size: 15px; color: var(--m2); margin-bottom: 40px; max-width: 480px; }

.btn-primary {
  display: inline-block; padding: 14px 36px; background: var(--gold);
  color: #0a0a0b; font-size: 15px; font-weight: 600; border-radius: 28px;
  border: none; cursor: pointer; transition: all 0.2s;
}
.btn-primary:hover { background: var(--gold2); transform: translateY(-1px); }

.scroll-hint {
  position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%);
  animation: bounce 2s ease-in-out infinite; color: var(--m); font-size: 24px;
}
@keyframes bounce { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(8px); } }

/* ===== Philosophy ===== */
.philosophy { max-width: 720px; margin: 0 auto; }
.philosophy p { font-size: 16px; color: var(--m2); line-height: 1.9; margin-bottom: 20px; }
.philosophy blockquote {
  border-left: 3px solid var(--gold); padding: 16px 24px; margin: 32px 0;
  background: var(--gold-bg); border-radius: 0 8px 8px 0;
  font-size: 18px; font-weight: 500; color: var(--text);
}

/* ===== Workflow Timeline ===== */
.workflow { background: var(--s1); }
.timeline {
  display: flex; justify-content: space-between; align-items: flex-start;
  position: relative; margin-top: 48px; gap: 12px;
}
.timeline::before {
  content: ''; position: absolute; top: 24px; left: 24px; right: 24px;
  height: 1px; background: var(--bd);
}
.timeline-step {
  display: flex; flex-direction: column; align-items: center;
  text-align: center; flex: 1; position: relative; z-index: 1;
}
.timeline-icon {
  width: 48px; height: 48px; border-radius: 50%; display: flex;
  align-items: center; justify-content: center; background: var(--s2);
  border: 1px solid var(--bd); margin-bottom: 14px; font-size: 20px;
  transition: all 0.3s;
}
.timeline-step:hover .timeline-icon {
  border-color: var(--gold); background: var(--gold-bg);
}
.timeline-step h4 { font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.timeline-step p { font-size: 12px; color: var(--m2); max-width: 120px; }

/* ===== Features ===== */
.feature-item {
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px;
  align-items: center; margin-bottom: 80px;
}
.feature-item:last-child { margin-bottom: 0; }
.feature-item:nth-child(even) .feature-text { order: 2; }
.feature-item:nth-child(even) .feature-visual { order: 1; }
.feature-text h3 { font-size: 24px; font-weight: 700; margin-bottom: 16px; }
.feature-text p { font-size: 15px; color: var(--m2); line-height: 1.8; }
.feature-text .feature-tag {
  display: inline-block; font-size: 12px; color: var(--gold);
  border: 1px solid var(--gold); border-radius: 12px;
  padding: 3px 10px; margin-top: 16px;
}
.feature-visual {
  background: var(--s1); border: 1px solid var(--bd); border-radius: 16px;
  padding: 24px; min-height: 200px;
}
.feature-mock { font-size: 13px; color: var(--m2); line-height: 1.8; }
.feature-mock .mock-header {
  font-size: 12px; color: var(--m); margin-bottom: 12px;
  padding-bottom: 8px; border-bottom: 1px solid var(--bd);
}
.feature-mock .mock-bubble {
  background: var(--s2); border-radius: 10px; padding: 12px 16px;
  margin-bottom: 8px; font-size: 13px;
}
.feature-mock .mock-bubble.ai { border-left: 2px solid var(--gold); }
.feature-mock .mock-bubble.user { border-left: 2px solid var(--m); }
.feature-mock .mock-dim {
  display: inline-block; background: var(--s2); border-radius: 8px;
  padding: 6px 12px; margin: 4px; font-size: 12px; border: 1px solid var(--bd);
}
.feature-mock .mock-dim-gold { border-color: var(--gold); color: var(--gold); }

/* Negotiation Tabs */
.nego-tabs { display: flex; gap: 8px; margin-bottom: 12px; }
.nego-tab {
  padding: 4px 12px; border-radius: 14px; border: 1px solid var(--bd);
  background: transparent; color: var(--m2); font-size: 12px;
  cursor: pointer; transition: all 0.2s; font-family: inherit;
}
.nego-tab.active { border-color: var(--gold); color: var(--gold); background: var(--gold-bg); }
.nego-panel { display: none; }
.nego-panel.active { display: block; }

/* ===== AI Styles ===== */
.styles-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 40px;
}
.style-card {
  background: var(--s1); border: 1px solid var(--bd); border-radius: 16px;
  padding: 28px; transition: border-color 0.3s;
}
.style-card:hover { border-color: var(--gold); }
.style-card-top { margin-bottom: 16px; }
.style-card h4 { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
.style-card .style-sub { font-size: 13px; color: var(--m2); }
.style-card .style-quote {
  background: var(--s2); border-radius: 10px; padding: 14px 16px;
  font-size: 13px; line-height: 1.6; color: var(--text); font-style: italic;
  border-left: 2px solid var(--gold);
}

/* ===== Pricing ===== */
.pricing-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 24px;
  max-width: 720px; margin: 40px auto 0;
}
.price-card {
  background: var(--s1); border: 1px solid var(--bd); border-radius: 16px;
  padding: 32px;
}
.price-card.pro { border-color: var(--gold); position: relative; overflow: hidden; }
.price-card.pro::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--gold2));
}
.price-card h4 { font-size: 20px; font-weight: 700; margin-bottom: 4px; }
.price-card .price { font-size: 14px; color: var(--m2); margin-bottom: 20px; }
.price-card ul { list-style: none; }
.price-card li {
  font-size: 14px; padding: 6px 0; color: var(--m2);
  display: flex; align-items: center; gap: 8px;
}
.price-card li::before { content: '\2713'; color: var(--green); font-size: 14px; font-weight: 700; }
.pricing-note { text-align: center; margin-top: 32px; font-size: 13px; color: var(--m); }

/* ===== Final CTA ===== */
.final-cta {
  text-align: center; position: relative; padding: 100px 24px;
}
.final-cta::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 50% 50%, rgba(200,168,106,0.05) 0%, transparent 70%);
  pointer-events: none;
}
.final-cta h2 { font-size: 28px; font-weight: 700; margin-bottom: 12px; }
.final-cta .section-sub { margin-bottom: 32px; }
.final-cta .cta-hint { font-size: 12px; color: var(--m); margin-top: 16px; }

/* ===== Footer ===== */
.footer {
  background: var(--s1); border-top: 1px solid var(--bd); padding: 40px 24px;
}
.footer-inner {
  max-width: 1080px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
}
.footer-brand { display: flex; align-items: center; gap: 10px; }
.footer-brand img { width: 20px; height: 20px; border-radius: 50%; }
.footer-brand span { font-size: 14px; color: var(--m2); }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 13px; color: var(--m); transition: color 0.2s; }
.footer-links a:hover { color: var(--gold); }
.footer-slogan {
  text-align: center; margin-top: 24px; font-size: 12px;
  color: var(--m); font-style: italic;
}

/* ===== Auth Modal ===== */
.auth-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.6); backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
}
.auth-panel {
  background: var(--s1); border: 1px solid var(--bd); border-radius: 16px;
  padding: 40px 32px; width: 100%; max-width: 400px; position: relative;
  border-top: 3px solid var(--gold);
}
.auth-close {
  position: absolute; top: 12px; right: 16px;
  background: none; border: none; color: var(--m2); font-size: 24px;
  cursor: pointer; transition: color 0.2s;
}
.auth-close:hover { color: var(--text); }
.auth-title { font-size: 22px; font-weight: 700; margin-bottom: 4px; }
.auth-error {
  font-size: 13px; color: var(--red); margin-bottom: 12px; min-height: 18px;
}
.auth-field { margin-bottom: 16px; }
.auth-field label {
  display: block; font-size: 13px; color: var(--m2); margin-bottom: 6px;
}
.auth-field input {
  width: 100%; padding: 10px 14px; background: var(--s2);
  border: 1px solid var(--bd); border-radius: 8px; color: var(--text);
  font-size: 14px; outline: none; transition: border-color 0.2s;
  font-family: inherit;
}
.auth-field input:focus { border-color: var(--gold); }
.auth-submit {
  width: 100%; margin-top: 8px; padding: 12px; font-size: 15px;
}
.auth-switch {
  text-align: center; margin-top: 20px; font-size: 13px; color: var(--m2);
}
.auth-switch a { color: var(--gold); cursor: pointer; margin-left: 4px; }
.auth-switch a:hover { color: var(--gold2); }

/* Nav auth buttons */
.nav-cta {
  padding: 6px 16px; font-size: 13px; border-radius: 20px;
}
.nav-user {
  display: flex; align-items: center; gap: 12px;
}
.nav-user-name { font-size: 13px; color: var(--gold); }

/* Price card CTA */
.price-cta {
  margin-top: 20px; width: 100%; padding: 10px; font-size: 14px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .section { padding: 64px 0; }
  .section-title { font-size: 24px; }
  .hero-title { font-size: 40px; }
  .hero-tagline { font-size: 18px; }
  .hero-orb { width: 120px; height: 120px; margin-bottom: 32px; }

  .timeline {
    flex-direction: column; gap: 0;
    padding-left: 36px; align-items: flex-start;
  }
  .timeline::before {
    top: 0; bottom: 0; left: 23px; right: auto;
    width: 1px; height: auto;
  }
  .timeline-step {
    flex-direction: row; text-align: left; gap: 16px;
    margin-bottom: 24px;
  }
  .timeline-step p { max-width: none; }

  .feature-item { grid-template-columns: 1fr; gap: 24px; margin-bottom: 48px; }
  .feature-item:nth-child(even) .feature-text { order: 1; }
  .feature-item:nth-child(even) .feature-visual { order: 2; }

  .styles-grid { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }

  .footer-inner { flex-direction: column; gap: 16px; text-align: center; }
}