/* Alpha Course — dark hero/footer, red accents, clean sections */

:root {
  --color-dark: #1a2332;
  --color-dark-card: #232f42;
  --color-red: #c41e3a;
  --color-red-hover: #a01830;
  --color-white: #ffffff;
  --color-text: #1a2332;
  --color-text-muted: #4a5568;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --max-width: 56rem;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --header-height: 5rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-white);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* Header — sticky, transparent over hero; solid background when scrolled */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.site-header.header-scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 1px 0 rgba(26, 35, 50, 0.06);
}

.site-header.header-scrolled .logo,
.site-header.header-scrolled .nav a {
  color: var(--color-text);
}

/* Join Us button: keep text white on dark background when scrolled (nav a would make it dark) */
.site-header.header-scrolled .nav a.btn-nav,
.site-header.header-scrolled .btn-nav {
  color: var(--color-white);
  background: var(--color-dark);
}

.site-header.header-scrolled .nav a.btn-nav:hover,
.site-header.header-scrolled .btn-nav:hover {
  background: #0f1319;
  color: var(--color-white);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-md);
  padding-bottom: var(--space-md);
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-white);
  text-decoration: none;
  letter-spacing: 0.02em;
  transition: color 0.2s ease;
}

.logo:hover {
  color: var(--color-white);
  opacity: 0.9;
}

.site-header.header-scrolled .logo:hover {
  color: var(--color-text);
}

.nav {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav a {
  color: var(--color-white);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  transition: color 0.2s ease;
}

.btn-nav {
  padding: 0.5rem 1rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.3);
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn-nav:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.4);
}

/* Hero — YouTube video backdrop, subtle dark scrim, white + red text */
.hero {
  position: relative;
  min-height: 75vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--color-dark);
  overflow: hidden;
}

/* YouTube (or MP4) full-bleed backdrop; iframe scaled to cover */
.hero-video-wrap {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-video-wrap iframe {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100vw;
  height: 56.25vw;
  min-width: 177.78vh;
  min-height: 100vh;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

/* Optional: use a self-hosted MP4 instead for better performance (add <video> inside .hero-video-wrap) */
.hero-video-wrap video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0.35) 0%, rgba(0, 0, 0, 0.5) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-2xl) var(--space-md);
}

/* Hero entrance: title and glass card animate in on load (respect reduced motion) */
@media (prefers-reduced-motion: no-preference) {
  .hero-title {
    opacity: 0;
    animation: heroReveal 0.8s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  }
  .hero-date-glass {
    animation: heroReveal 0.8s cubic-bezier(0.22, 1, 0.36, 1) 0.15s forwards;
    opacity: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-title,
  .hero-date-glass { opacity: 1; }
}

@keyframes heroReveal {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 var(--space-sm);
  color: var(--color-white);
  letter-spacing: -0.02em;
}

.hero-highlight {
  color: var(--color-red);
}

/* Liquid glass card for hero date — stacks above CTA */
.hero-date-glass {
  display: inline-block;
  margin: 0 0 var(--space-md);
  padding: 0.75rem 1.5rem;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.15), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.hero-date-glass .hero-date {
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--color-white);
  margin: 0;
  opacity: 1;
  letter-spacing: 0.02em;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-lg);
  transition: background 0.2s ease;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--color-red);
  color: var(--color-white);
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary:hover {
  background: var(--color-red-hover);
  color: var(--color-white);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(196, 30, 58, 0.35);
}

.btn-arrow {
  flex-shrink: 0;
}

.btn-large {
  padding: 1rem 2rem;
  font-size: 1.0625rem;
}

/* Sections — padding-top clears fixed header so content doesn't scroll under it */
.section {
  padding-top: calc(var(--header-height) + var(--space-xl));
  padding-bottom: var(--space-2xl);
}

.section-light {
  background: var(--color-white);
}

#what-happens.section-light {
  background: #f8f9fb;
}

/* Section pretitle (e.g. "The Experience", "Testimonials") */
.section-pretitle {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-red);
  margin: 0 0 var(--space-sm);
  text-align: center;
}

.section-pretitle-dark {
  color: rgba(255, 255, 255, 0.9);
}

/* Section title — only last word bold */
.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 400;
  margin: 0 0 var(--space-md);
  color: var(--color-text);
  text-align: center;
  letter-spacing: -0.02em;
}

.section-title .title-bold {
  font-weight: 700;
}

.cta-section .section-title,
.cta-section-title {
  color: var(--color-white);
}

.cta-section .section-title .title-bold {
  font-weight: 700;
}

.section-intro-block {
  margin: 0 auto var(--space-xl);
  max-width: 42rem;
  text-align: center;
}

.section-intro-block .section-intro {
  margin-bottom: var(--space-md);
}

.section-intro-block .section-intro:last-child {
  margin-bottom: 0;
}

.section-intro {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  margin: 0 auto var(--space-xl);
  max-width: 42rem;
  text-align: center;
  line-height: 1.7;
}

.stats-intro {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin: 0 auto var(--space-lg);
  max-width: 40rem;
  text-align: center;
  line-height: 1.7;
}

/* What is Alpha — intro video + stats */
.intro-video-wrapper {
  position: relative;
  width: 100%;
  max-width: 48rem;
  margin: 0 auto var(--space-xl);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 2px solid var(--color-red);
  box-shadow: 0 8px 32px rgba(26, 35, 50, 0.12);
}

.intro-video-wrapper::before {
  content: "";
  display: block;
  padding-bottom: 56.25%;
}

.intro-video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2xl);
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(26, 35, 50, 0.08);
}

.stat {
  text-align: center;
  min-width: 6rem;
}

.stat-number {
  display: block;
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-red);
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
  line-height: 1.1;
}

.stat-label {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

/* What happens — 4 pillar cards (wider layout, hover expand + shadow) */
#what-happens .container {
  max-width: 72rem;
}

.pillars {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-lg);
  margin-top: var(--space-lg);
}

@media (max-width: 64rem) {
  .pillars {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 32rem) {
  .pillars {
    grid-template-columns: 1fr;
  }
}

.pillar {
  text-align: center;
  padding: var(--space-lg);
}

.pillar-card {
  --pillar-shadow: 0 2px 12px rgba(26, 35, 50, 0.06);
  --pillar-shadow-hover: 0 12px 32px rgba(26, 35, 50, 0.12);
  background: var(--color-white);
  border: 1px solid rgba(26, 35, 50, 0.08);
  border-radius: var(--radius-lg);
  box-shadow: var(--pillar-shadow);
  transition:
    transform 0.3s ease,
    box-shadow 0.3s ease,
    border-color 0.3s ease;
}

.pillar-card:hover {
  transform: scale(1.03);
  box-shadow: var(--pillar-shadow-hover);
  border-color: rgba(196, 30, 58, 0.15);
}

.pillar-card:hover .pillar-icon {
  transform: scale(1.08);
}

.pillar-number {
  display: block;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
  letter-spacing: 0.02em;
}

.pillar-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.5rem;
  height: 3.5rem;
  margin-bottom: var(--space-sm);
  border-radius: 0.5rem;
  background: rgba(196, 30, 58, 0.1);
  color: var(--color-red);
  transition: transform 0.3s ease;
}

.pillar-card:hover .pillar-icon {
  background: rgba(196, 30, 58, 0.14);
}

.pillar h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 0.25rem;
  color: var(--color-text);
}

.pillar-time {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  font-style: italic;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}

.pillar p {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.5;
}

/* Hear from Alumni — video grid */
.video-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  margin-top: var(--space-md);
}

@media (max-width: 40rem) {
  .video-grid {
    grid-template-columns: 1fr;
  }
}

.video-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(26, 35, 50, 0.1);
  box-shadow: 0 4px 20px rgba(26, 35, 50, 0.08);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.video-card:hover {
  box-shadow: 0 12px 32px rgba(26, 35, 50, 0.12);
  transform: translateY(-2px);
}

.video-wrapper {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
}

.video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.video-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: var(--space-sm) var(--space-md) 0;
  color: var(--color-text);
}

.video-desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0.25rem var(--space-md) var(--space-md);
}

/* Ready to explore — dark CTA section with city-street background */
.section-dark {
  position: relative;
  color: var(--color-white);
  padding: var(--space-2xl) 0;
  overflow: hidden;
}

.cta-bg {
  position: absolute;
  inset: 0;
  background: #1a1e29 url("https://images.unsplash.com/photo-1542401886-65d6c61db217?w=1600") center/cover no-repeat;
}

.cta-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(26, 30, 41, 0.75) 0%, rgba(26, 30, 41, 0.88) 50%, rgba(26, 30, 41, 0.95) 100%);
}

.cta-section .container {
  position: relative;
  z-index: 1;
  max-width: 44rem;
}

.cta-inner {
  text-align: center;
}

.cta-section .section-title,
.cta-section h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 400;
  margin: 0 0 var(--space-md);
  color: var(--color-white);
  letter-spacing: -0.02em;
}

.cta-intro {
  font-size: 1.0625rem;
  color: #a0a4b2;
  margin: 0 0 var(--space-xl);
  line-height: 1.65;
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
}

/* Interest Meeting card — liquid glass (frosted) */
.next-meeting-card {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 1.25rem;
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  text-align: left;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.next-meeting-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0 0 var(--space-md);
  color: var(--color-white);
}

.meeting-detail {
  display: flex;
  align-items: flex-start;
  gap: 0.875rem;
  margin-bottom: 1rem;
}

.meeting-detail:last-child {
  margin-bottom: 0;
}

.meeting-icon-badge {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 0.5rem;
  background: #e53e3e;
  color: var(--color-white);
}

.meeting-detail-text {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.meeting-label {
  font-size: 0.8125rem;
  font-weight: 400;
  color: #a0a4b2;
}

.meeting-value {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.4;
}

/* CTA button — pill, accent red-orange, shadow */
.btn-cta {
  background: #e53e3e;
  color: var(--color-white);
  border-radius: 999px;
  padding: 1rem 2rem;
  font-size: 1.0625rem;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(229, 62, 62, 0.35);
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-cta:hover {
  background: #c53030;
  color: var(--color-white);
  box-shadow: 0 6px 18px rgba(229, 62, 62, 0.4);
  transform: translateY(-1px);
}

.cta-footer-tagline {
  font-size: 0.875rem;
  color: #a0a4b2;
  margin: var(--space-lg) 0 0;
  letter-spacing: 0.02em;
}

/* Scroll reveal — slide-in on scroll; respect reduced motion */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1), transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 0;
    transform: none;
    transition: opacity 0.3s ease;
  }
  .reveal.visible {
    opacity: 1;
  }
}

/* Stagger delay for pillar cards */
.pillars .pillar-card.reveal:nth-child(1) { transition-delay: 0.05s; }
.pillars .pillar-card.reveal:nth-child(2) { transition-delay: 0.12s; }
.pillars .pillar-card.reveal:nth-child(3) { transition-delay: 0.19s; }
.pillars .pillar-card.reveal:nth-child(4) { transition-delay: 0.26s; }

/* Focus styles — visible and consistent */
a:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--color-red);
  outline-offset: 2px;
}

.cta-section .btn-cta:focus-visible {
  outline-color: var(--color-white);
  outline-offset: 3px;
}

/* Anchor scroll margin so fixed header doesn't hide section */
#about,
#what-happens,
#alumni,
#signup,
#alpha-app {
  scroll-margin-top: var(--header-height);
}

/* Alpha App section — two columns: text + badges left, red panel with phones right */
.section-alpha-app {
  padding: var(--space-2xl) 0;
  background: #f5f5f7;
}

.alpha-app-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
  max-width: 64rem;
}

.alpha-app-content {
  padding-right: var(--space-lg);
}

.alpha-app-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  color: var(--color-text);
  margin: 0 0 var(--space-md);
  line-height: 1.2;
}

.alpha-app-desc {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-lg);
  max-width: 32rem;
}

.alpha-app-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
}

.app-badge {
  display: inline-block;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.app-badge:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.app-badge img {
  display: block;
  height: 40px;
  width: auto;
  object-fit: contain;
}

.app-badge-google img {
  height: 48px;
}

.alpha-app-visual {
  background: #e0212f;
  border-radius: 1.25rem;
  padding: 2.5rem 2rem;
  box-shadow: 0 10px 40px rgba(224, 33, 47, 0.25), 0 4px 12px rgba(0, 0, 0, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 320px;
}

.alpha-app-phones {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  filter: drop-shadow(0 8px 24px rgba(0, 0, 0, 0.15));
}

@media (max-width: 768px) {
  .alpha-app-inner {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    text-align: center;
  }

  .alpha-app-content {
    padding-right: 0;
  }

  .alpha-app-desc {
    max-width: none;
  }

  .alpha-app-badges {
    justify-content: center;
  }

  .alpha-app-visual {
    min-height: 260px;
    padding: 1.5rem 1rem;
  }
}