:root {
  --bg-dark: #030303;
  --surface-dark: #0a0a0a;
  --border-dim: #1e1e1e;
  --border-bright: #444444;
  --text-primary: #ffffff;
  --text-secondary: #888888;
  --radius: 4px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-primary);
  overflow-x: hidden;
  min-height: 100vh;
}

/* Background Grid */
.bg-grid {
  position: fixed;
  inset: 0;
  background-image: linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
                    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events: none;
  z-index: 0;
}

/* Intro Stage Wrapper */
.intro-stage {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  pointer-events: none;
}

.intro-welcome {
  font-size: 1.1rem;
  font-weight: 300;
  letter-spacing: 10px;
  color: var(--text-secondary);
  opacity: 0;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}

/* Seamless Flex Lockup */
.intro-brand-container {
  display: flex;
  align-items: baseline;
  justify-content: center;
  transform-origin: center center;
}

.intro-saisan {
  font-size: 4.2rem;
  font-weight: 900;
  letter-spacing: 2px;
  color: #ffffff;
  opacity: 0;
  white-space: nowrap;
}

/* Expanding reveal container */
.intro-suffix-wrap {
  width: 0px;
  overflow: hidden;
  display: inline-flex;
  align-items: baseline;
}

.intro-suffix {
  font-size: 2.1rem;
  font-weight: 700;
  color: var(--text-secondary);
  white-space: nowrap;
  opacity: 0;
}

/* Navigation Header */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: flex-end;
  align-items: center;
  padding: 1.8rem 6%;
  z-index: 10;
}

/* Compact, sleek button dimensions */
.btn {
  padding: 0.45rem 0.95rem;
  border-radius: var(--radius);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.2px;
  cursor: pointer;
  transition: all 0.25s ease;
  line-height: 1;
}

.btn-primary {
  background: var(--text-primary);
  color: var(--bg-dark);
  border: 1px solid var(--text-primary);
}

.btn-primary:hover {
  background: var(--bg-dark);
  color: var(--text-primary);
  border-color: var(--text-primary);
}

.btn-large {
  padding: 0.65rem 1.4rem;
  font-size: 0.82rem;
}

/* Hero Main */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 1.5rem 5rem 1.5rem;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 850px;
  text-align: center;
}

.hero-title {
  font-size: 4.2rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -2px;
  margin-bottom: 1.8rem;
}

.title-line {
  display: block;
  opacity: 0;
  transform: translateY(15px);
}

.hero-subtitle {
  font-size: 1.1rem;
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 2.2rem auto;
  opacity: 0;
  transform: translateY(15px);
}

.hero-cta {
  opacity: 0;
  transform: translateY(15px);
}

/* Footer Styles */
.site-footer {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding-bottom: 1.5rem;
  z-index: 10;
}

.footer-separator {
  width: 0%;
  height: 1px;
  background-color: var(--border-dim);
  margin: 0 auto 1.5rem auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0;
  transform: translateY(10px);
}

.footer-contacts {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.contact-link {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.contact-link:hover {
  color: var(--text-primary);
}

.divider {
  color: var(--border-bright);
}

/* Auth Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  backdrop-filter: blur(16px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  z-index: 1100;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.modal-card {
  background: var(--surface-dark);
  border: 1px solid var(--border-dim);
  border-radius: var(--radius);
  padding: 2.2rem 1.8rem;
  width: 100%;
  max-width: 380px;
  position: relative;
}

.close-btn {
  position: absolute;
  top: 0.8rem;
  right: 1rem;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.2rem;
  cursor: pointer;
}

.auth-tabs {
  display: flex;
  border-bottom: 1px solid var(--border-dim);
  margin-bottom: 1.5rem;
}

.tab-btn {
  flex: 1;
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 0.5rem 0;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  position: relative;
}

.tab-btn.active {
  color: var(--text-primary);
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--text-primary);
}

.auth-form {
  display: none;
  flex-direction: column;
  gap: 0.9rem;
}

.auth-form.active {
  display: flex;
}

.form-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.form-header p {
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.input-group label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-secondary);
}

.input-group input {
  padding: 0.6rem 0.75rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-dim);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.82rem;
  outline: none;
}

.input-group input:focus {
  border-color: var(--border-bright);
}

.auth-status {
  margin-top: 0.8rem;
  font-size: 0.78rem;
  text-align: center;
  color: var(--text-secondary);
}

@media (max-width: 768px) {
  .hero-title { font-size: 2.6rem; }
  .intro-saisan { font-size: 2.6rem; }
  .intro-suffix { font-size: 1.3rem; }
  .footer-content {
    flex-direction: column;
    gap: 0.8rem;
    text-align: center;
  }
}