/* =============================================
   DESIGN TOKENS
   ============================================= */
:root {
  --bg:           #0b0d17;
  --bg-alt:       #0f1120;
  --surface:      #151828;
  --surface-hover:#1c2035;
  --border:       rgba(255,255,255,0.07);
  --text-primary: #f0f2ff;
  --text-secondary:#8b92b8;
  --text-muted:   #4f5576;
  --accent:       #7c6df5;
  --accent-2:     #c084fc;
  --accent-glow:  rgba(124,109,245,0.35);
  --radius-sm:    8px;
  --radius-md:    16px;
  --radius-lg:    24px;
  --font-display: 'Outfit', sans-serif;
  --font-body:    'Inter', sans-serif;
  --transition:   0.25s ease;
  --max-w:        1100px;
}

/* =============================================
   RESET & BASE
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* =============================================
   UTILITY
   ============================================= */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 2rem;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* =============================================
   NAV
   ============================================= */
.nav {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 100;
  padding: 1.25rem 2rem;
  transition: background var(--transition), backdrop-filter var(--transition);
}

.nav.scrolled {
  background: rgba(11,13,23,0.85);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color var(--transition);
}

.nav-links a:hover { color: var(--text-primary); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: var(--transition);
}

/* =============================================
   BUTTONS
   ============================================= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 100px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 4px 24px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.2);
  background: var(--surface);
}

/* =============================================
   HERO
   ============================================= */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding: 6rem 2rem 4rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('../assets/hero_bg.png');
  background-size: cover;
  background-position: center;
  opacity: 0.55;
  z-index: 0;
}

.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center bottom, rgba(11,13,23,0.7) 0%, rgba(11,13,23,0.95) 75%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 780px;
}

.hero-eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 1.25rem;
  opacity: 0;
  animation: fadeUp 0.7s 0.2s forwards;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.7s 0.35s forwards;
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--text-secondary);
  max-width: 580px;
  margin: 0 auto 2.5rem;
  line-height: 1.8;
  opacity: 0;
  animation: fadeUp 0.7s 0.5s forwards;
}

.hero-subtitle em { color: var(--accent-2); font-style: normal; }

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.7s 0.65s forwards;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  z-index: 1;
  opacity: 0;
  animation: fadeIn 1s 1.2s forwards;
}

.hero-scroll-hint span {
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--text-muted), transparent);
  animation: scrollPulse 2s infinite;
}

/* =============================================
   SECTIONS
   ============================================= */
.section {
  padding: 7rem 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
  background: rgba(124,109,245,0.1);
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  border: 1px solid rgba(124,109,245,0.2);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.section-body {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 640px;
  line-height: 1.85;
}

/* =============================================
   COURSE GRID
   ============================================= */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 3rem;
}

.course-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: all var(--transition);
  overflow: hidden;
}

.course-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(135deg, rgba(124,109,245,0.08), rgba(192,132,252,0.04));
  opacity: 0;
  transition: opacity var(--transition);
}

a.course-card:hover {
  border-color: rgba(124,109,245,0.4);
  transform: translateY(-4px);
  box-shadow: 0 20px 50px rgba(0,0,0,0.4), 0 0 0 1px rgba(124,109,245,0.15);
}

a.course-card:hover::before { opacity: 1; }

.course-card-coming {
  opacity: 0.5;
  cursor: default;
}

.course-card-tag {
  display: inline-flex;
  align-self: flex-start;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.25rem 0.7rem;
  border-radius: 100px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
}

.course-card-tag-soon {
  background: var(--surface-hover);
  color: var(--text-muted);
}

.course-card-icon {
  font-size: 2.5rem;
  line-height: 1;
  margin: 0.25rem 0;
}

.course-card-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.course-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  flex: 1;
}

.course-card-cta {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-2);
  margin-top: 0.5rem;
  transition: gap var(--transition);
}

/* =============================================
   CONTACT
   ============================================= */
.contact-inner { max-width: 640px; }

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2rem;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--surface);
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.contact-link:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.2);
  background: var(--surface-hover);
  transform: translateY(-2px);
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(1); }
  50%       { opacity: 0.8; transform: scaleY(1.1); }
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 720px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: fixed;
    inset: 0;
    background: rgba(11,13,23,0.97);
    backdrop-filter: blur(20px);
    align-items: center;
    justify-content: center;
    gap: 2rem;
    z-index: 99;
  }

  .nav-links.open { display: flex; }
  .nav-links a { font-size: 1.5rem; }
  .nav-toggle { display: flex; z-index: 101; }

  .section { padding: 5rem 0; }
  .hero-cta { flex-direction: column; align-items: center; }
  .btn { width: 100%; max-width: 280px; justify-content: center; }
}
/* =============================================
   LIGHT MODE
   ============================================= */
html[data-theme="light"] {
  --bg:           #f8f9ff;
  --bg-alt:       #eef0fb;
  --surface:      #ffffff;
  --surface-hover:#eef0ff;
  --border:       rgba(0,0,0,0.09);
  --text-primary: #0b0d17;
  --text-secondary:#4a5076;
  --text-muted:   #8b92b8;
  --accent-glow:  rgba(124,109,245,0.12);
}

html[data-theme="light"] .nav.scrolled {
  background: rgba(248,249,255,0.92);
}

@media (max-width: 720px) {
  html[data-theme="light"] .nav-links {
    background: rgba(248,249,255,0.98);
  }
}

html[data-theme="light"] .hero-bg::after {
  background: radial-gradient(ellipse at center bottom, rgba(248,249,255,0.7) 0%, rgba(248,249,255,0.95) 75%);
}

html[data-theme="light"] .btn-ghost:hover,
html[data-theme="light"] .contact-link:hover {
  border-color: rgba(0,0,0,0.15);
}

html[data-theme="light"] a.course-card:hover {
  box-shadow: 0 20px 50px rgba(0,0,0,0.1), 0 0 0 1px rgba(124,109,245,0.15);
}

/* Theme Toggle Button */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: 100px;
  width: 2.1rem;
  height: 2.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: all var(--transition);
  flex-shrink: 0;
}
.theme-toggle:hover {
  background: var(--surface);
  color: var(--text-primary);
  border-color: rgba(124,109,245,0.35);
}