/* ── Covision-style Intro Landing ── */

:root {
  --intro-purple: #4f46e5;
  --intro-purple-dark: #3730a3;
  --intro-purple-light: #818cf8;
  --intro-purple-bg: #eef2ff;
  --intro-text: #0f172a;
  --intro-muted: #64748b;
  --intro-border: #e2e8f0;
  --intro-radius: 12px;
  --intro-shadow: 0 20px 50px rgba(79, 70, 229, 0.12);
}

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

.intro-page {
  margin: 0;
  font-family: 'Pretendard Variable', Pretendard, -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  color: var(--intro-text);
  background: #fff;
  scroll-behavior: smooth;
}

.intro-container {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.intro-container--narrow {
  width: min(760px, 100%);
}

/* Header */
.intro-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s, box-shadow 0.25s;
}

.intro-header--scrolled {
  border-bottom-color: var(--intro-border);
  box-shadow: 0 4px 24px rgba(15, 23, 42, 0.06);
}

.intro-header__inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
}

.intro-header__brand {
  flex-shrink: 0;
}

.intro-header__logo {
  height: 36px;
  width: auto;
  display: block;
}

.intro-header__nav {
  display: flex;
  gap: 1.75rem;
  margin-left: auto;
}

.intro-header__nav a {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--intro-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.intro-header__nav a:hover {
  color: var(--intro-purple);
}

.intro-header__actions {
  display: flex;
  gap: 0.5rem;
}

.intro-header__menu {
  display: none;
  flex-direction: column;
  gap: 5px;
  margin-left: auto;
  padding: 0.5rem;
  border: none;
  background: transparent;
  cursor: pointer;
}

.intro-header__menu span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--intro-text);
  border-radius: 1px;
}

.intro-header__mobile {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1rem 1.5rem 1.25rem;
  border-top: 1px solid var(--intro-border);
  background: #fff;
}

.intro-header__mobile a {
  font-weight: 600;
  color: var(--intro-text);
  text-decoration: none;
}

.intro-header__mobile[hidden] {
  display: none !important;
}

/* Buttons */
.intro-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.intro-btn--sm {
  padding: 0.45rem 1rem;
  font-size: 0.82rem;
}

.intro-btn--lg {
  padding: 0.9rem 1.75rem;
  font-size: 0.95rem;
}

.intro-btn--primary {
  background: var(--intro-purple);
  color: #fff;
  box-shadow: 0 8px 24px rgba(79, 70, 229, 0.35);
}

.intro-btn--primary:hover {
  background: var(--intro-purple-dark);
  transform: translateY(-1px);
}

.intro-btn--ghost {
  background: transparent;
  color: var(--intro-purple);
  border-color: transparent;
}

.intro-btn--ghost:hover {
  background: var(--intro-purple-bg);
}

.intro-btn--outline {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.45);
}

.intro-btn--outline:hover {
  background: rgba(255, 255, 255, 0.2);
}

.intro-btn--white {
  background: #fff;
  color: var(--intro-purple);
  box-shadow: var(--intro-shadow);
}

.intro-btn--white:hover {
  transform: translateY(-2px);
}

/* Hero */
.intro-hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 1.5rem 5rem;
  overflow: hidden;
  background: linear-gradient(145deg, #312e81 0%, #4f46e5 45%, #6366f1 100%);
  color: #fff;
}

.intro-hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.intro-hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.45;
}

.intro-hero__orb--1 {
  width: 480px;
  height: 480px;
  top: -10%;
  right: -5%;
  background: #a5b4fc;
}

.intro-hero__orb--2 {
  width: 360px;
  height: 360px;
  bottom: 5%;
  left: -8%;
  background: #c4b5fd;
}

.intro-hero__grid {
  position: absolute;
  inset: 0;
  opacity: 0.06;
  background-image:
    linear-gradient(#fff 1px, transparent 1px),
    linear-gradient(90deg, #fff 1px, transparent 1px);
  background-size: 48px 48px;
}

.intro-hero__inner {
  position: relative;
  max-width: 720px;
  text-align: center;
}

.intro-hero__eyebrow {
  display: inline-block;
  margin: 0 0 1.25rem;
  padding: 0.35rem 1rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.22);
}

.intro-hero__title {
  margin: 0 0 1.25rem;
  font-size: clamp(2.2rem, 6vw, 3.5rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.03em;
}

.intro-hero__title-accent {
  background: linear-gradient(90deg, #fff, #fde68a);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.intro-hero__lead {
  margin: 0 0 2rem;
  font-size: clamp(1rem, 2vw, 1.15rem);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.88);
}

.intro-hero__lead strong {
  color: #fde68a;
}

.intro-hero__cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.intro-hero__stats {
  display: flex;
  justify-content: center;
  gap: 2.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.intro-hero__stats li {
  text-align: center;
}

.intro-hero__stats strong {
  display: block;
  font-size: 1.75rem;
  font-weight: 900;
}

.intro-hero__stats span {
  font-size: 0.78rem;
  opacity: 0.75;
}

.intro-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-decoration: none;
}

.intro-scroll__line {
  width: 1px;
  height: 40px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.6), transparent);
  animation: introScrollPulse 2s ease-in-out infinite;
}

@keyframes introScrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(0.8); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* Sections */
.intro-section {
  padding: clamp(4rem, 8vw, 6rem) 0;
}

.intro-section--light {
  background: #fff;
}

.intro-section--gray {
  background: #f8fafc;
}

.intro-section--purple {
  background: linear-gradient(160deg, #312e81, #4338ca);
  color: #fff;
}

.intro-section__eyebrow {
  margin: 0 0 0.75rem;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--intro-purple);
}

.intro-section__eyebrow--light {
  color: #a5b4fc;
}

.intro-section__title {
  margin: 0 0 2.5rem;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: -0.03em;
}

.intro-section__title em {
  font-style: normal;
  color: var(--intro-purple);
}

.intro-section__title--light {
  color: #fff;
}

.intro-section__title--light em {
  color: #fde68a;
}

/* Cards */
.intro-cards {
  display: grid;
  gap: 1.25rem;
}

.intro-cards--3 {
  grid-template-columns: repeat(3, 1fr);
}

.intro-card {
  padding: 1.75rem;
  border-radius: var(--intro-radius);
  border: 1px solid var(--intro-border);
  background: #fff;
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.04);
  transition: transform 0.25s, box-shadow 0.25s;
}

.intro-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--intro-shadow);
}

.intro-card__icon {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.intro-card__title {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  font-weight: 800;
}

.intro-card__desc {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--intro-muted);
}

/* Modules */
.intro-modules__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.intro-modules__tab {
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 999px;
  padding: 0.5rem 1rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.75);
  background: rgba(255, 255, 255, 0.06);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.intro-modules__tab--active,
.intro-modules__tab:hover {
  background: #fff;
  color: var(--intro-purple);
  border-color: #fff;
}

.intro-modules__panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
  padding: 2rem;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.intro-modules__content {
  display: none;
}

.intro-modules__content--active {
  display: block;
}

.intro-modules__content h3 {
  margin: 0 0 1rem;
  font-size: 1.35rem;
}

.intro-modules__content ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.intro-modules__content li {
  padding: 0.35rem 0;
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.5;
}

.intro-mock-window {
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.25);
}

.intro-mock-window__bar {
  display: flex;
  gap: 6px;
  padding: 0.65rem 0.85rem;
  background: #f1f5f9;
}

.intro-mock-window__bar span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #cbd5e1;
}

.intro-mock-window__bar span:first-child { background: #f87171; }
.intro-mock-window__bar span:nth-child(2) { background: #fbbf24; }
.intro-mock-window__bar span:nth-child(3) { background: #4ade80; }

.intro-mock-window__body {
  display: flex;
  min-height: 200px;
}

.intro-mock-sidebar {
  width: 28%;
  background: #eef2ff;
}

.intro-mock-main {
  flex: 1;
  padding: 1rem;
}

.intro-mock-line {
  height: 8px;
  margin-bottom: 0.65rem;
  border-radius: 4px;
  background: #e2e8f0;
}

.intro-mock-line--lg {
  width: 60%;
  height: 12px;
  margin-bottom: 1rem;
  background: #c7d2fe;
}

.intro-mock-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-top: 1rem;
}

.intro-mock-grid span {
  height: 48px;
  border-radius: 6px;
  background: #f1f5f9;
}

/* Vision */
.intro-vision {
  text-align: center;
}

.intro-vision__quote {
  margin: 0;
  padding: 2.5rem;
  border-radius: 16px;
  background: var(--intro-purple-bg);
  border: 1px solid #c7d2fe;
}

.intro-vision__slogan {
  margin: 0 0 0.5rem;
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  color: var(--intro-purple);
}

.intro-vision__tagline {
  margin: 0 0 0.75rem;
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 800;
}

.intro-vision__verse {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--intro-muted);
}

.intro-vision__desc {
  margin: 0;
  color: var(--intro-muted);
  line-height: 1.7;
}

/* FAQ */
.intro-faq {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.intro-faq__item {
  border: 1px solid var(--intro-border);
  border-radius: var(--intro-radius);
  background: #fff;
  overflow: hidden;
}

.intro-faq__item summary {
  padding: 1rem 1.25rem;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

.intro-faq__item summary::-webkit-details-marker {
  display: none;
}

.intro-faq__item p {
  margin: 0;
  padding: 0 1.25rem 1rem;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--intro-muted);
}

/* CTA */
.intro-cta {
  padding: 4rem 0;
  background: linear-gradient(135deg, var(--intro-purple), #6366f1);
  text-align: center;
}

.intro-cta__title {
  margin: 0 0 1.5rem;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 900;
  color: #fff;
  line-height: 1.35;
}

/* Footer */
.intro-footer {
  padding: 2rem 0;
  background: #0f172a;
  color: rgba(255, 255, 255, 0.5);
  text-align: center;
}

.intro-footer__logo {
  height: 32px;
  margin-bottom: 1rem;
  opacity: 0.7;
  filter: brightness(0) invert(1);
}

.intro-footer__copy {
  margin: 0 0 0.5rem;
  font-size: 0.72rem;
}

.intro-footer__link {
  color: #a5b4fc;
  font-size: 0.82rem;
  font-weight: 600;
  text-decoration: none;
}

.intro-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  z-index: 90;
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: var(--intro-purple);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 800;
  cursor: pointer;
  box-shadow: var(--intro-shadow);
}

.intro-top[hidden] {
  display: none !important;
}

@media (max-width: 900px) {
  .intro-header__nav,
  .intro-header__actions {
    display: none;
  }

  .intro-header__menu {
    display: flex;
  }

  .intro-cards--3 {
    grid-template-columns: 1fr;
  }

  .intro-modules__panel {
    grid-template-columns: 1fr;
  }

  .intro-modules__mock {
    order: -1;
  }

  .intro-hero__stats {
    gap: 1.5rem;
  }
}

@media (max-width: 600px) {
  .intro-hero__cta {
    flex-direction: column;
  }

  .intro-hero__cta .intro-btn {
    width: 100%;
  }
}