/* ============================================
   main.css — Design System Đức Hoàng Media
   Biến CSS toàn cục, dùng chung cho mọi trang
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400..900;1,400..900&display=swap');

/* ─── CSS Reset & Base ─────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* ── Brand Colors ── */
  --brand-primary:   #7C6FFF;
  --brand-primary-dark: #5A4FD9;
  --brand-gold:      #F5A623;
  --brand-fire:      #FF6B35;
  --brand-success:   #2ECC71;
  --brand-danger:    #E74C3C;
  --brand-warning:   #F39C12;

  /* ── Dark Theme Backgrounds ── */
  --bg-base:   #0A0C14;
  --bg-surface: #11141F;
  --bg-card:   #181B2A;
  --bg-card-hover: #1E2235;
  --bg-overlay: rgba(10, 12, 20, 0.8);
  --bg-glass:  rgba(255, 255, 255, 0.04);
  --bg-glass-hover: rgba(255, 255, 255, 0.08);

  /* ── Text ── */
  --text-primary:   #F0F2FF;
  --text-secondary: #8B90B5;
  --text-muted:     #535675;
  --text-link:      #7C6FFF;

  /* ── Borders ── */
  --border:       rgba(255, 255, 255, 0.08);
  --border-brand: rgba(124, 111, 255, 0.4);
  --border-gold:  rgba(245, 166, 35, 0.4);

  /* ── Gradients ── */
  --gradient-hero:   linear-gradient(135deg, #0A0C14 0%, #141729 60%, #0A0C14 100%);
  --gradient-brand:  linear-gradient(135deg, #7C6FFF 0%, #5A4FD9 100%);
  --gradient-gold:   linear-gradient(135deg, #F5A623 0%, #FF6B35 100%);
  --gradient-fire:   linear-gradient(135deg, #FF6B35 0%, #FF3D71 100%);
  --gradient-card:   linear-gradient(145deg, rgba(124,111,255,0.12) 0%, rgba(124,111,255,0.03) 100%);
  --gradient-glow:   radial-gradient(ellipse at top, rgba(124,111,255,0.15) 0%, transparent 70%);

  /* ── Shadows ── */
  --shadow-sm:    0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md:    0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg:    0 16px 48px rgba(0, 0, 0, 0.5);
  --shadow-brand: 0 8px 32px rgba(124, 111, 255, 0.3);
  --shadow-gold:  0 8px 32px rgba(245, 166, 35, 0.25);

  /* ── Spacing ── */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* ── Border Radius ── */
  --radius-sm:  8px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  32px;
  --radius-full: 9999px;

  /* ── Typography ── */
  --font-heading: 'Playfair Display', serif;
  --font-body:    'Playfair Display', serif;

  /* ── Transitions ── */
  --transition-fast: 0.15s ease;
  --transition-base: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* ── Layout ── */
  --container-max: 1200px;
  --nav-height:    72px;
}

/* ─── Base Styles ──────────────────────────────────────────────────────── */
html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ─── Typography ───────────────────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.2;
  font-weight: 700;
  color: var(--text-primary);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.8rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.6rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.8rem); }

p { color: var(--text-secondary); line-height: 1.7; }

a {
  color: var(--text-link);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--brand-primary); }

/* ─── Layout Utilities ─────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

.section--sm {
  padding: var(--space-2xl) 0;
}

/* ─── Flex & Grid Utilities ────────────────────────────────────────────── */
.flex          { display: flex; }
.flex-center   { display: flex; align-items: center; justify-content: center; }
.flex-between  { display: flex; align-items: center; justify-content: space-between; }
.flex-col      { display: flex; flex-direction: column; }
.gap-sm        { gap: var(--space-sm); }
.gap-md        { gap: var(--space-md); }
.gap-lg        { gap: var(--space-lg); }
.gap-xl        { gap: var(--space-xl); }

/* ─── Buttons ──────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 14px 28px;
  border-radius: var(--radius-full);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  white-space: nowrap;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--brand-secondary), var(--brand-primary), var(--brand-secondary));
  background-size: 200% auto;
  color: #fff;
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.2), 0 8px 24px rgba(124, 111, 255, 0.4);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.1);
}
.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.3), 0 12px 32px rgba(124, 111, 255, 0.6);
  color: #fff;
  background-position: right center;
}
.btn-primary:active {
  transform: translateY(1px) scale(0.98);
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.1), 0 4px 16px rgba(124, 111, 255, 0.3);
}
.btn-primary::after {
  content: '';
  position: absolute;
  top: 0; left: -100%; width: 50%; height: 100%;
  background: linear-gradient(to right, rgba(255,255,255,0) 0%, rgba(255,255,255,0.3) 50%, rgba(255,255,255,0) 100%);
  transform: skewX(-25deg);
  transition: all 0.75s ease;
}
.btn-primary:hover::after {
  animation: shine 1.5s infinite;
}

.btn-gold {
  background: linear-gradient(135deg, #FFB75E, var(--brand-gold), #ED8F03);
  background-size: 200% auto;
  color: #fff;
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.3), 0 8px 24px rgba(245, 166, 35, 0.4);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.2);
}
.btn-gold:hover {
  transform: translateY(-3px);
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.5), 0 12px 32px rgba(245, 166, 35, 0.7);
  color: #fff;
  background-position: right center;
}
.btn-gold:active {
  transform: translateY(1px) scale(0.98);
  box-shadow: inset 0 2px 0px rgba(255,255,255,0.1), 0 4px 16px rgba(245, 166, 35, 0.3);
}
.btn-gold::after {
  content: '';
  position: absolute;
  top: 0; left: -100%; width: 50%; height: 100%;
  background: linear-gradient(to right, rgba(255,255,255,0) 0%, rgba(255,255,255,0.4) 50%, rgba(255,255,255,0) 100%);
  transform: skewX(-25deg);
  transition: all 0.75s ease;
}
.btn-gold:hover::after {
  animation: shine 1.5s infinite;
}

@keyframes shine {
  0% { left: -100%; }
  100% { left: 200%; }
}

.sticky-register-btn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 999;
  background: linear-gradient(135deg, var(--brand-gold), #FF5722);
  color: #fff;
  padding: 16px 32px;
  border-radius: var(--radius-full);
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.1rem;
  text-decoration: none;
  box-shadow: 0 10px 30px rgba(245, 166, 35, 0.5), inset 0 2px 0 rgba(255,255,255,0.3);
  transform: translateY(100px) scale(0.9);
  opacity: 0;
  pointer-events: none;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  display: flex;
  align-items: center;
  gap: 10px;
  animation: pulse-gold 2s infinite;
  border: 2px solid rgba(255,255,255,0.2);
  cursor: pointer;
}
.sticky-register-btn.show {
  transform: translateY(0) scale(1);
  opacity: 1;
  pointer-events: auto;
}
.sticky-register-btn:hover {
  transform: translateY(-5px) scale(1.05);
  box-shadow: 0 15px 40px rgba(245, 166, 35, 0.7), inset 0 2px 0 rgba(255,255,255,0.5);
  color: #fff;
}
@keyframes pulse-gold {
  0%, 100% { box-shadow: 0 10px 30px rgba(245, 166, 35, 0.5), inset 0 2px 0 rgba(255,255,255,0.3); }
  50% { box-shadow: 0 10px 50px rgba(245, 166, 35, 0.8), inset 0 2px 0 rgba(255,255,255,0.3); }
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid var(--border);
}
.btn-outline:hover {
  background: var(--bg-glass-hover);
  border-color: var(--brand-primary);
  color: var(--brand-primary);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--brand-primary);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(124, 111, 255, 0.25);
}
.btn-ghost i {
  transition: transform 0.3s ease;
}
.btn-ghost:hover i {
  transform: translateY(4px);
}

.btn-danger {
  background: var(--brand-danger);
  color: #fff;
}
.btn-danger:hover {
  background: #c0392b;
  color: #fff;
  transform: translateY(-1px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.875rem;
}

.btn-lg {
  padding: 18px 40px;
  font-size: 1.125rem;
}

/* ─── Cards ────────────────────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-base);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-brand);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card-glass {
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

/* ─── Badges ───────────────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  font-family: var(--font-heading);
}

.badge-brand { background: rgba(124,111,255,0.15); color: var(--brand-primary); border: 1px solid var(--border-brand); }
.badge-gold  { background: rgba(245,166,35,0.15);  color: var(--brand-gold);    border: 1px solid var(--border-gold); }
.badge-success { background: rgba(46,204,113,0.15); color: var(--brand-success); border: 1px solid rgba(46,204,113,0.3); }
.badge-danger  { background: rgba(231,76,60,0.15);  color: var(--brand-danger);  border: 1px solid rgba(231,76,60,0.3); }

/* ─── Navigation ───────────────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 100;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(10, 12, 20, 0.92);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
}

.navbar .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--text-primary);
  text-decoration: none;
}

.nav-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-brand);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}
.nav-links a:hover { color: var(--text-primary); }

/* ─── Section Headers ──────────────────────────────────────────────────── */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--brand-primary);
  margin-bottom: var(--space-md);
}

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

.section-desc {
  font-size: 1.1rem;
  max-width: 600px;
  color: var(--text-secondary);
}

/* ─── Divider ──────────────────────────────────────────────────────────── */
.divider {
  width: 60px;
  height: 3px;
  background: var(--gradient-brand);
  border-radius: var(--radius-full);
  margin: var(--space-md) 0;
}

/* ─── Form Elements ────────────────────────────────────────────────────── */
.input {
  width: 100%;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--transition-fast);
}
.input:focus {
  border-color: var(--brand-primary);
}
.input::placeholder {
  color: var(--text-muted);
}

.select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%238B90B5' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}
.select option {
  background-color: var(--bg-card);
  color: var(--text-primary);
}

/* ─── Alerts / Toasts ──────────────────────────────────────────────────── */
.alert {
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}
.alert-error   { background: rgba(231,76,60,0.12); border: 1px solid rgba(231,76,60,0.3); color: #ff8a80; }
.alert-success { background: rgba(46,204,113,0.12); border: 1px solid rgba(46,204,113,0.3); color: #69f0ae; }
.alert-info    { background: rgba(124,111,255,0.12); border: 1px solid rgba(124,111,255,0.3); color: #b5adff; }

/* ─── Loading Spinner ──────────────────────────────────────────────────── */
.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--brand-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.loading-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(8px);
}

/* ─── Social Icons ─────────────────────────────────────────────────────── */
.social-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: all var(--transition-base);
  text-decoration: none;
}
.social-icon:hover {
  border-color: var(--brand-primary);
  color: var(--brand-primary);
  background: rgba(124,111,255,0.1);
  transform: translateY(-2px);
}
.social-icon.youtube:hover { border-color: #FF0000; color: #FF0000; background: rgba(255,0,0,0.1); }
.social-icon.tiktok:hover  { border-color: #69C9D0; color: #69C9D0; background: rgba(105,201,208,0.1); }
.social-icon.facebook:hover{ border-color: #1877F2; color: #1877F2; background: rgba(24,119,242,0.1); }

/* ─── Animations ───────────────────────────────────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-12px); }
}
@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px rgba(124,111,255,0.3); }
  50%       { box-shadow: 0 0 40px rgba(124,111,255,0.6); }
}
@keyframes shimmer {
  from { background-position: -200% 0; }
  to   { background-position: 200% 0; }
}

.animate-fadeInUp { animation: fadeInUp 0.6s ease forwards; }
.animate-float     { animation: float 4s ease-in-out infinite; }

/* ─── Scrollbar ────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-surface); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ─── Responsive ───────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  :root { --nav-height: 60px; }
  .container { padding: 0 var(--space-md); }
  .section { padding: var(--space-2xl) 0; }
  .nav-links { display: none; }
  .btn-lg { padding: 14px 28px; font-size: 1rem; }
}