/* ==========================================================================
   STYLE.CSS — Landing Page Lớp học Thầy Long
   Bộ màu: Navy #0F2B46 | Teal #10B981 | Amber #F59E0B | Light #F8FAFC
   Mobile-first, responsive, smooth animations
   ========================================================================== */

/* ==========================================================================
   1. CSS CUSTOM PROPERTIES (Biến màu & thiết kế)
   ========================================================================== */
:root {
  /* Màu sắc chính */
  --navy:       #0F2B46;
  --navy-lgt:   #1a3d5c;
  --navy-dark:  #091d30;
  --teal:       #10B981;
  --teal-lgt:   #34d399;
  --teal-dark:  #059669;
  --amber:      #F59E0B;
  --amber-lgt:  #fbbf24;
  --amber-dark: #d97706;
  --light:      #F8FAFC;
  --light-2:    #EEF2F7;
  --text:       #1E293B;
  --text-soft:  #475569;
  --text-muted: #94a3b8;
  --red:        #EF4444;
  --white:      #ffffff;

  /* Typography */
  --font: 'Be Vietnam Pro', 'Segoe UI', sans-serif;
  --font-display: 'Lora', Georgia, serif;

  /* Spacing tokens */
  --sp-xs:  0.5rem;
  --sp-sm:  0.75rem;
  --sp-md:  1rem;
  --sp-lg:  1.5rem;
  --sp-xl:  2rem;
  --sp-2xl: 3rem;
  --sp-3xl: 4rem;
  --sp-4xl: 6rem;

  /* Border radius */
  --r-sm:  6px;
  --r-md:  12px;
  --r-lg:  18px;
  --r-xl:  24px;
  --r-2xl: 32px;
  --r-full: 9999px;

  /* Shadows (color-tinted, layered) */
  --shadow-card:
    0 1px 3px rgba(15,43,70,0.08),
    0 4px 16px rgba(15,43,70,0.10),
    0 8px 32px rgba(15,43,70,0.06);
  --shadow-card-teal:
    0 4px 16px rgba(16,185,129,0.15),
    0 8px 32px rgba(15,43,70,0.12);
  --shadow-card-amber:
    0 4px 16px rgba(245,158,11,0.2),
    0 8px 32px rgba(15,43,70,0.12);
  --shadow-btn-amber:
    0 4px 12px rgba(245,158,11,0.4),
    0 2px 4px rgba(245,158,11,0.3);
  --shadow-btn-teal:
    0 4px 12px rgba(16,185,129,0.35),
    0 2px 4px rgba(16,185,129,0.25);
  --shadow-nav:
    0 4px 24px rgba(15,43,70,0.35);

  /* Transitions */
  --ease:        cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --t-fast:   0.15s var(--ease);
  --t-med:    0.3s var(--ease);
  --t-slow:   0.5s var(--ease);
  --t-spring: 0.4s var(--ease-spring);
}


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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: clamp(0.9rem, 2vw, 1rem);
  line-height: 1.7;
  color: var(--text);
  background: var(--white);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  text-decoration: none;
  color: inherit;
}

ul { list-style: none; }

button {
  font-family: var(--font);
  cursor: pointer;
  border: none;
  background: none;
}


/* ==========================================================================
   3. UTILITY CLASSES
   ========================================================================== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--sp-lg);
}

/* Section spacing */
.section {
  padding: var(--sp-3xl) 0;
}

@media (min-width: 768px) {
  .section { padding: var(--sp-4xl) 0; }
}

/* Section header pattern */
.section-header {
  text-align: center;
  margin-bottom: var(--sp-2xl);
}

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
  background: rgba(16,185,129,0.1);
  border: 1px solid rgba(16,185,129,0.25);
  border-radius: var(--r-full);
  padding: 0.25rem 0.85rem;
  margin-bottom: var(--sp-sm);
}

.section-title {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 800;
  color: var(--navy);
  line-height: 1.25;
  letter-spacing: -0.03em;
  margin-bottom: var(--sp-sm);
}

.section-subtitle {
  font-size: clamp(0.95rem, 2.2vw, 1.05rem);
  color: var(--text-soft);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}


/* ==========================================================================
   4. BUTTONS
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4em;
  font-family: var(--font);
  font-weight: 700;
  border-radius: var(--r-full);
  cursor: pointer;
  border: 2px solid transparent;
  transition: transform var(--t-spring), box-shadow var(--t-med), background var(--t-fast), color var(--t-fast);
  white-space: nowrap;
  min-height: 44px;
  padding: 0.6rem 1.5rem;
  font-size: 0.9rem;
}

/* Amber (primary CTA) */
.btn-amber {
  background: var(--amber);
  color: var(--navy-dark);
  box-shadow: var(--shadow-btn-amber);
}
.btn-amber:hover  { background: var(--amber-lgt); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(245,158,11,0.45); }
.btn-amber:active { transform: translateY(0); box-shadow: none; }
.btn-amber:focus-visible { outline: 3px solid var(--amber); outline-offset: 3px; }

/* Teal (secondary CTA) */
.btn-teal {
  background: var(--teal);
  color: var(--white);
  box-shadow: var(--shadow-btn-teal);
}
.btn-teal:hover  { background: var(--teal-dark); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(16,185,129,0.4); }
.btn-teal:active { transform: translateY(0); }
.btn-teal:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }

/* Teal outline */
.btn-teal-outline {
  background: transparent;
  color: var(--teal);
  border-color: var(--teal);
}
.btn-teal-outline:hover  { background: var(--teal); color: var(--white); transform: translateY(-2px); }
.btn-teal-outline:active { transform: translateY(0); }
.btn-teal-outline:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }

/* Ghost (white outline) */
.btn-ghost {
  background: transparent;
  color: var(--white);
  border-color: rgba(255,255,255,0.4);
}
.btn-ghost:hover  { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.7); transform: translateY(-2px); }
.btn-ghost:active { transform: translateY(0); }
.btn-ghost:focus-visible { outline: 3px solid rgba(255,255,255,0.6); outline-offset: 3px; }

/* Teal ghost (for drawer) */
.btn-teal-ghost {
  background: transparent;
  color: var(--teal);
  border: 2px solid rgba(16,185,129,0.4);
}
.btn-teal-ghost:hover { background: rgba(16,185,129,0.08); border-color: var(--teal); transform: translateY(-2px); }

/* Sizes */
.btn-hero  { padding: 0.85rem 2rem; font-size: 1rem; }
.btn-xl    { padding: 1rem 2.5rem; font-size: 1.05rem; }
.btn-sm    { padding: 0.45rem 1.1rem; font-size: 0.82rem; min-height: 36px; }
.btn-card-cta { width: 100%; margin-top: var(--sp-md); justify-content: center; padding: 0.8rem 1rem; font-size: 0.95rem; }


/* ==========================================================================
   5. BADGES
   ========================================================================== */
.cbadge {
  display: inline-flex;
  align-items: center;
  gap: 0.3em;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  border-radius: var(--r-full);
  padding: 0.2rem 0.7rem;
  white-space: nowrap;
}

.cbadge-free     { background: rgba(239,68,68,0.12);  color: #dc2626; border: 1px solid rgba(239,68,68,0.3); }
.cbadge-hot      { background: rgba(249,115,22,0.12); color: #ea580c; border: 1px solid rgba(249,115,22,0.3); }
.cbadge-soon     { background: rgba(16,185,129,0.12); color: #059669; border: 1px solid rgba(16,185,129,0.3); }
.cbadge-upcoming { background: rgba(245,158,11,0.12); color: #b45309; border: 1px solid rgba(245,158,11,0.3); }

.cbadge-sm { font-size: 0.65rem; padding: 0.15rem 0.55rem; }


/* ==========================================================================
   6. ANIMATION SYSTEM (Intersection Observer)
   ========================================================================== */
[data-animate] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

[data-animate].is-visible {
  opacity: 1;
  transform: translateY(0);
}

[data-delay="80"]  { transition-delay: 0.08s; }
[data-delay="100"] { transition-delay: 0.10s; }
[data-delay="160"] { transition-delay: 0.16s; }
[data-delay="200"] { transition-delay: 0.20s; }
[data-delay="240"] { transition-delay: 0.24s; }


/* ==========================================================================
   7. NAVIGATION
   ========================================================================== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 900;
  background: rgba(9, 29, 48, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255,255,255,0.07);
  transition: box-shadow var(--t-med);
}

.navbar.scrolled {
  box-shadow: var(--shadow-nav);
}

.nav-container {
  display: flex;
  align-items: center;
  gap: var(--sp-lg);
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--sp-lg);
  height: 64px;
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
  text-decoration: none;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--teal), var(--teal-dark));
  color: var(--white);
  font-weight: 800;
  font-size: 0.85rem;
  border-radius: var(--r-sm);
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.logo-text {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.02em;
}

/* Desktop nav links */
.nav-links {
  display: none;
  gap: var(--sp-xs);
  margin-left: auto;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: rgba(255,255,255,0.75);
  padding: 0.5rem 0.75rem;
  border-radius: var(--r-sm);
  transition: color var(--t-fast), background var(--t-fast);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--white);
  background: rgba(255,255,255,0.07);
}
.nav-link:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

.nav-end {
  display: flex;
  align-items: center;
  gap: var(--sp-sm);
  margin-left: auto;
}

/* Desktop: show links */
@media (min-width: 768px) {
  .nav-links { display: flex; margin-left: auto; }
  .nav-end { margin-left: 0; }
}

/* Hamburger */
.hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px; height: 40px;
  padding: 8px;
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: background var(--t-fast);
  flex-shrink: 0;
}

.hamburger span {
  display: block;
  width: 100%; height: 2px;
  background: rgba(255,255,255,0.85);
  border-radius: 2px;
  transition: transform var(--t-med), opacity var(--t-fast);
}

.hamburger:hover { background: rgba(255,255,255,0.08); }
.hamburger:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

/* Hamburger active state */
.hamburger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.is-open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Hide hamburger on desktop */
@media (min-width: 768px) {
  .hamburger { display: none; }
  .btn-nav-cta { display: inline-flex; }
}

/* Mobile overlay */
.mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(9, 29, 48, 0.7);
  z-index: 910;
  backdrop-filter: blur(2px);
  opacity: 0;
  transition: opacity var(--t-med);
}

.mobile-overlay.is-open {
  display: block;
  opacity: 1;
}

/* Mobile drawer */
.mobile-drawer {
  position: fixed;
  top: 0; right: 0; bottom: 0;
  width: min(320px, 90vw);
  background: var(--navy-dark);
  z-index: 920;
  padding: var(--sp-xl);
  display: flex;
  flex-direction: column;
  gap: var(--sp-xl);
  transform: translateX(100%);
  transition: transform var(--t-med);
  box-shadow: -8px 0 40px rgba(0,0,0,0.4);
}

.mobile-drawer.is-open {
  transform: translateX(0);
}

.drawer-close {
  align-self: flex-end;
  width: 36px; height: 36px;
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
  border-radius: var(--r-full);
  transition: background var(--t-fast), color var(--t-fast);
}
.drawer-close:hover { background: rgba(255,255,255,0.1); color: var(--white); }

.drawer-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.drawer-links {
  display: flex;
  flex-direction: column;
  gap: var(--sp-xs);
  flex: 1;
}

.drawer-links a {
  font-size: 1rem;
  font-weight: 600;
  color: rgba(255,255,255,0.8);
  padding: 0.7rem 1rem;
  border-radius: var(--r-md);
  transition: background var(--t-fast), color var(--t-fast);
  display: block;
}

.drawer-links a:hover { background: rgba(255,255,255,0.07); color: var(--white); }

.drawer-actions {
  display: flex;
  flex-direction: column;
  gap: var(--sp-sm);
}

.btn-drawer-cta { width: 100%; font-size: 0.95rem; }


/* ==========================================================================
   8. HERO SECTION
   ========================================================================== */
.hero {
  position: relative;
  min-height: 100svh;
  background: var(--navy-dark);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 80px 0 var(--sp-2xl);
  overflow: hidden;
}

/* SVG grain overlay */
.hero-grain {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 1;
}

/* Layered radial gradient glows */
.hero-glow {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}

.hero-glow-1 {
  width: 700px; height: 700px;
  top: -200px; right: -150px;
  background: radial-gradient(circle, rgba(16,185,129,0.18) 0%, transparent 70%);
  z-index: 0;
}

.hero-glow-2 {
  width: 500px; height: 500px;
  bottom: -100px; left: -100px;
  background: radial-gradient(circle, rgba(245,158,11,0.10) 0%, transparent 70%);
  z-index: 0;
}

.hero-glow-3 {
  width: 900px; height: 600px;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(ellipse, rgba(16,185,129,0.05) 0%, transparent 65%);
  z-index: 0;
}

.hero-container {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--sp-lg);
  display: flex;
  flex-direction: column;
  gap: var(--sp-2xl);
  align-items: center;
}

/* Hero content */
.hero-content {
  text-align: center;
  max-width: 720px;
}

/* Status badge */
.hero-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--teal-lgt);
  background: rgba(16,185,129,0.12);
  border: 1px solid rgba(16,185,129,0.3);
  border-radius: var(--r-full);
  padding: 0.35rem 1rem;
  margin-bottom: var(--sp-lg);
  letter-spacing: 0.02em;
}

.status-pulse {
  width: 8px; height: 8px;
  background: var(--teal);
  border-radius: 50%;
  animation: pulse-ring 2s ease infinite;
  flex-shrink: 0;
}

@keyframes pulse-ring {
  0%   { box-shadow: 0 0 0 0 rgba(16,185,129,0.5); }
  70%  { box-shadow: 0 0 0 6px rgba(16,185,129,0); }
  100% { box-shadow: 0 0 0 0 rgba(16,185,129,0); }
}

/* Hero heading */
.hero-heading {
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1.15;
  letter-spacing: -0.04em;
  margin-bottom: 0.25rem;
}

.hero-heading-em {
  font-style: italic;
  font-family: var(--font-display);
  color: var(--teal-lgt);
  font-weight: 600;
  letter-spacing: -0.02em;
}

/* Tagline */
.hero-tagline {
  font-size: clamp(1.3rem, 3.5vw, 2rem);
  font-weight: 800;
  color: var(--amber-lgt);
  letter-spacing: -0.025em;
  margin-bottom: var(--sp-lg);
  line-height: 1.2;
}

/* Description */
.hero-desc {
  font-size: clamp(0.9rem, 2.2vw, 1.05rem);
  color: rgba(255,255,255,0.7);
  line-height: 1.7;
  margin-bottom: var(--sp-xl);
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

/* Hero CTA buttons */
.hero-btns {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-sm);
  justify-content: center;
}

/* Stats bar */
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: var(--sp-sm) var(--sp-xl);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--r-xl);
  padding: var(--sp-lg) var(--sp-xl);
  backdrop-filter: blur(8px);
  width: 100%;
  max-width: 680px;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.stat-num {
  font-size: clamp(1.2rem, 3vw, 1.6rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1;
  letter-spacing: -0.03em;
}

.stat-plus { font-size: 0.7em; color: var(--teal-lgt); }

.stat-free {
  font-size: clamp(0.85rem, 2vw, 1rem);
  color: var(--red);
  background: rgba(239,68,68,0.15);
  border-radius: var(--r-full);
  padding: 0.2rem 0.7rem;
  letter-spacing: 0.05em;
}

.stat-lbl {
  font-size: 0.75rem;
  font-weight: 500;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.03em;
}

.stat-sep {
  width: 1px;
  height: 36px;
  background: rgba(255,255,255,0.12);
}

/* Scroll indicator */
.hero-scroll-hint {
  position: absolute;
  bottom: var(--sp-xl);
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
}

.scroll-line {
  width: 2px; height: 40px;
  background: linear-gradient(to bottom, rgba(16,185,129,0.6), transparent);
  border-radius: 2px;
  animation: scroll-bounce 2s ease infinite;
}

@keyframes scroll-bounce {
  0%, 100% { transform: scaleY(1); opacity: 1; }
  50% { transform: scaleY(0.6); opacity: 0.4; }
}


/* ==========================================================================
   9. ABOUT SECTION
   ========================================================================== */
.about-section {
  background: var(--light);
}

/* About grid: target audience cards */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-lg);
  margin-bottom: var(--sp-xl);
}

@media (min-width: 560px) { .about-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .about-grid { grid-template-columns: repeat(4, 1fr); } }

.about-card {
  background: var(--white);
  border-radius: var(--r-lg);
  padding: var(--sp-xl) var(--sp-lg);
  box-shadow: var(--shadow-card);
  transition: transform var(--t-spring), box-shadow var(--t-med);
  border: 1px solid rgba(15,43,70,0.06);
}

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

.about-icon {
  width: 52px; height: 52px;
  background: var(--icon-bg, var(--navy));
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: var(--sp-md);
  opacity: 0.9;
}

.about-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: var(--sp-xs);
  line-height: 1.35;
}

.about-card p {
  font-size: 0.875rem;
  color: var(--text-soft);
  line-height: 1.65;
}

/* Feature checklist */
.about-features {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-sm);
  background: rgba(16,185,129,0.05);
  border: 1px solid rgba(16,185,129,0.15);
  border-radius: var(--r-lg);
  padding: var(--sp-xl);
}

@media (min-width: 640px) { .about-features { grid-template-columns: repeat(2, 1fr); } }

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--text);
  font-weight: 500;
}

.feature-check {
  flex-shrink: 0;
  font-size: 1rem;
  line-height: 1.5;
}


/* ==========================================================================
   10. COURSES SECTION
   ========================================================================== */
.courses-section {
  background: var(--white);
}

.courses-group-label {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: var(--sp-lg);
  margin-top: var(--sp-2xl);
}

.courses-group-label:first-of-type { margin-top: 0; }

.group-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.courses-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-xl);
  margin-bottom: var(--sp-sm);
}

@media (min-width: 700px) { .courses-grid { grid-template-columns: repeat(2, 1fr); } }

/* Base card style */
.course-card {
  border-radius: var(--r-xl);
  padding: var(--sp-xl);
  display: flex;
  flex-direction: column;
  gap: var(--sp-md);
  transition: transform var(--t-spring), box-shadow var(--t-med);
  position: relative;
}

/* Active card */
.course-active {
  background: var(--white);
  border: 1px solid rgba(15,43,70,0.1);
  box-shadow: var(--shadow-card);
}

.course-active:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-card-teal);
}

/* Upcoming card — muted appearance */
.course-upcoming {
  background: var(--light);
  border: 2px dashed rgba(15,43,70,0.18);
  opacity: 0.82;
}

.course-upcoming::before {
  content: 'Sắp mở';
  position: absolute;
  top: var(--sp-md);
  right: var(--sp-md);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--amber-dark);
  background: rgba(245,158,11,0.12);
  border-radius: var(--r-full);
  padding: 0.2rem 0.6rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.card-badges-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-xs);
}

/* Subject bar */
.card-subject-bar {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  border-radius: var(--r-md);
  padding: 0.4rem 0.9rem;
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.03em;
  width: fit-content;
}

.subject-ta {
  background: rgba(16,185,129,0.12);
  color: var(--teal-dark);
  border: 1px solid rgba(16,185,129,0.25);
}

.subject-toan {
  background: rgba(245,158,11,0.12);
  color: var(--amber-dark);
  border: 1px solid rgba(245,158,11,0.25);
}

.upcoming-subject { opacity: 0.65; }
.subject-emoji { font-size: 1rem; }

.card-title {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--navy);
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.course-upcoming .card-title { color: var(--text-soft); }

.card-teacher {
  font-size: 0.875rem;
  color: var(--text-soft);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.card-teacher strong { color: var(--navy); font-weight: 700; }
.teacher-icon { font-size: 1rem; }

/* Card info list */
.card-info-list {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  font-size: 0.875rem;
  color: var(--text);
}

.card-info-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  line-height: 1.5;
}

.ci-icon { flex-shrink: 0; width: 1.1em; }

.ci-free {
  color: #dc2626;
  font-weight: 600;
  background: rgba(239,68,68,0.07);
  border-radius: var(--r-sm);
  padding: 0.3rem 0.5rem;
  margin: 0 -0.5rem;
}

/* Zoom info box */
.zoom-box {
  background: rgba(15,43,70,0.04);
  border: 1px solid rgba(15,43,70,0.1);
  border-radius: var(--r-md);
  padding: var(--sp-sm) var(--sp-md);
}

.zoom-box-title {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--navy);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: var(--sp-xs);
  opacity: 0.8;
}

.zoom-rows { display: flex; flex-direction: column; gap: 0.3rem; }

.zoom-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
}

.zoom-key {
  color: var(--text-soft);
  font-weight: 500;
  min-width: 95px;
  flex-shrink: 0;
}

.zoom-val {
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--navy);
  background: rgba(15,43,70,0.06);
  border-radius: var(--r-sm);
  padding: 0.15rem 0.45rem;
}

/* Card QR block */
.card-qr-block {
  background: rgba(15,43,70,0.03);
  border: 1px solid rgba(15,43,70,0.08);
  border-radius: var(--r-md);
  padding: var(--sp-md);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-xs);
}

.qr-group-name {
  font-size: 0.8rem;
  color: var(--text-soft);
}

.qr-group-name strong { color: var(--navy); }

.qr-img {
  width: 140px; height: 140px;
  object-fit: cover;
  border-radius: var(--r-md);
  border: 2px solid rgba(15,43,70,0.1);
}

.qr-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Upcoming notice */
.upcoming-notice-box {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.2);
  border-radius: var(--r-md);
  padding: var(--sp-sm) var(--sp-md);
  font-size: 0.875rem;
  color: var(--amber-dark);
  font-weight: 500;
  line-height: 1.5;
  margin-top: auto;
}

.notice-bell { font-size: 1rem; flex-shrink: 0; margin-top: 0.1rem; }


/* ==========================================================================
   11. SCHEDULE SECTION
   ========================================================================== */
.schedule-section {
  background: linear-gradient(160deg, rgba(15,43,70,0.04) 0%, var(--light) 60%, rgba(16,185,129,0.04) 100%);
}

/* Desktop table — hidden on mobile */
.schedule-table-wrap {
  overflow-x: auto;
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-card);
  margin-bottom: var(--sp-lg);
  display: none;
}

@media (min-width: 640px) { .schedule-table-wrap { display: block; } }

.schedule-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  font-size: 0.875rem;
  min-width: 620px;
}

.schedule-table th,
.schedule-table td {
  padding: 0.85rem 0.6rem;
  text-align: center;
  border: 1px solid rgba(15,43,70,0.07);
}

.schedule-table thead tr {
  background: var(--navy);
}

.schedule-table th {
  color: rgba(255,255,255,0.85);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
}

.th-time { color: rgba(255,255,255,0.6) !important; font-style: italic; }
.th-active-ta   { color: var(--teal-lgt) !important; }
.th-active-toan { color: var(--amber-lgt) !important; }

.td-time {
  font-weight: 700;
  color: var(--navy);
  background: rgba(15,43,70,0.04);
  font-size: 0.8rem;
  white-space: nowrap;
}

.td-empty { background: rgba(15,43,70,0.01); }

.td-class { vertical-align: top; padding: 0.6rem; }

.td-class-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  border-radius: var(--r-sm);
  padding: 0.5rem 0.4rem;
}

.td-ta .td-class-inner {
  background: rgba(16,185,129,0.1);
  border: 1px solid rgba(16,185,129,0.2);
}

.td-toan .td-class-inner {
  background: rgba(245,158,11,0.1);
  border: 1px solid rgba(245,158,11,0.2);
}

.td-icon { font-size: 1.1rem; }

.td-name {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--navy);
  line-height: 1.2;
}

.td-teacher {
  font-size: 0.7rem;
  color: var(--text-soft);
}

/* Schedule legend */
.schedule-legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-lg);
  justify-content: center;
  margin-bottom: var(--sp-lg);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-soft);
}

.legend-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* Mobile schedule cards — shown only on mobile */
.schedule-cards {
  display: flex;
  flex-direction: column;
  gap: var(--sp-lg);
  margin-bottom: var(--sp-lg);
}

@media (min-width: 640px) { .schedule-cards { display: none; } }

.scard {
  background: var(--white);
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.scard-head {
  display: flex;
  align-items: center;
  gap: var(--sp-md);
  padding: var(--sp-md) var(--sp-lg);
  border-bottom: 1px solid rgba(15,43,70,0.07);
}

.scard-ta .scard-head   { background: rgba(16,185,129,0.08); }
.scard-toan .scard-head { background: rgba(245,158,11,0.08); }

.scard-emoji { font-size: 1.6rem; flex-shrink: 0; }

.scard-head h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 0.2rem;
}

.scard-body {
  padding: var(--sp-md) var(--sp-lg);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.scard-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  gap: var(--sp-sm);
}

.scard-row span:first-child { color: var(--text-soft); font-weight: 500; }
.scard-row span:last-child  { color: var(--text); }

.schedule-footnote {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
}


/* ==========================================================================
   12. ACTION ZONE
   ========================================================================== */
.action-section {
  position: relative;
  background: var(--navy);
  padding: var(--sp-4xl) 0;
  overflow: hidden;
  text-align: center;
}

.action-grain {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 1;
}

.action-glow-1 {
  position: absolute;
  width: 500px; height: 500px;
  top: -100px; right: -100px;
  background: radial-gradient(circle, rgba(16,185,129,0.15) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}

.action-glow-2 {
  position: absolute;
  width: 400px; height: 400px;
  bottom: -80px; left: -80px;
  background: radial-gradient(circle, rgba(245,158,11,0.1) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}

.action-inner {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-lg);
}

.action-heading {
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  font-weight: 900;
  color: var(--white);
  letter-spacing: -0.04em;
  line-height: 1.15;
}

.action-sub {
  font-size: clamp(0.95rem, 2.5vw, 1.1rem);
  color: rgba(255,255,255,0.7);
  max-width: 480px;
  line-height: 1.65;
}

.action-btns {
  display: flex;
  flex-direction: column;
  gap: var(--sp-sm);
  width: 100%;
  max-width: 420px;
}

@media (min-width: 480px) {
  .action-btns {
    flex-direction: row;
    justify-content: center;
    max-width: none;
    width: auto;
  }
}

.action-note {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.45);
}


/* ==========================================================================
   13. ZALO COMMUNITY SECTION
   ========================================================================== */
.zalo-section {
  background: var(--light);
}

.zalo-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-xl);
}

@media (min-width: 640px) { .zalo-grid { grid-template-columns: repeat(2, 1fr); } }

.zalo-card {
  background: var(--white);
  border-radius: var(--r-xl);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform var(--t-spring), box-shadow var(--t-med);
  border: 1px solid rgba(15,43,70,0.08);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.zalo-card:hover {
  transform: translateY(-4px);
}

.zalo-ta:hover   { box-shadow: var(--shadow-card-teal); }
.zalo-toan:hover { box-shadow: var(--shadow-card-amber); }

.zalo-card-header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--sp-md);
  padding: var(--sp-lg);
  border-bottom: 1px solid rgba(15,43,70,0.07);
}

.zalo-ta .zalo-card-header   { background: rgba(16,185,129,0.07); }
.zalo-toan .zalo-card-header { background: rgba(245,158,11,0.07); }

.zalo-emoji { font-size: 2rem; flex-shrink: 0; }

.zalo-card-header h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 0.15rem;
}

.zalo-card-header p {
  font-size: 0.8rem;
  color: var(--text-soft);
}

.zalo-qr-wrap {
  padding: var(--sp-lg) var(--sp-xl);
  display: flex;
  justify-content: center;
}

.zalo-qr {
  width: clamp(160px, 40vw, 220px);
  height: clamp(160px, 40vw, 220px);
  object-fit: cover;
  border-radius: var(--r-md);
  border: 2px solid rgba(15,43,70,0.1);
  box-shadow: 0 4px 16px rgba(15,43,70,0.12);
}

.zalo-scan-text {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--navy);
  text-align: center;
  margin-bottom: var(--sp-xs);
}

.zalo-desc-text {
  font-size: 0.8rem;
  color: var(--text-soft);
  text-align: center;
  padding: 0 var(--sp-lg) var(--sp-lg);
  line-height: 1.55;
}


/* ==========================================================================
   14. FOOTER
   ========================================================================== */
.footer {
  background: var(--navy-dark);
  color: rgba(255,255,255,0.7);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-2xl);
  padding-top: var(--sp-3xl);
  padding-bottom: var(--sp-3xl);
}

@media (min-width: 640px)  { .footer-inner { grid-template-columns: 1fr 1fr; } }
@media (min-width: 900px)  { .footer-inner { grid-template-columns: 2fr 1fr 1fr; } }

.footer-brand .footer-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: var(--sp-md);
}

.footer-brand .logo-text { color: var(--white); }

.footer-tagline {
  font-size: 0.925rem;
  font-weight: 600;
  color: rgba(255,255,255,0.85);
  margin-bottom: var(--sp-xs);
}

.footer-subdesc {
  font-size: 0.83rem;
  color: rgba(255,255,255,0.45);
  line-height: 1.6;
}

.footer-col-title {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.45);
  margin-bottom: var(--sp-md);
}

.footer-link-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-link-list a {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.65);
  transition: color var(--t-fast);
}

.footer-link-list a:hover { color: var(--white); }
.footer-link-list a:focus-visible { outline: 1px solid var(--teal); outline-offset: 2px; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.07);
  padding: var(--sp-lg) 0;
}

.footer-bottom p {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.35);
  text-align: center;
}


/* ==========================================================================
   15. ZOOM MODAL
   ========================================================================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(9,29,48,0.8);
  backdrop-filter: blur(6px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-lg);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-med);
}

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

.modal-box {
  background: var(--white);
  border-radius: var(--r-xl);
  width: 100%;
  max-width: 520px;
  padding: var(--sp-xl) var(--sp-xl);
  position: relative;
  transform: scale(0.95) translateY(12px);
  transition: transform var(--t-spring);
  max-height: 90vh;
  overflow-y: auto;
}

.modal-overlay.is-open .modal-box {
  transform: scale(1) translateY(0);
}

.modal-close-btn {
  position: absolute;
  top: var(--sp-md);
  right: var(--sp-md);
  width: 36px; height: 36px;
  font-size: 0.9rem;
  color: var(--text-soft);
  border-radius: var(--r-full);
  transition: background var(--t-fast), color var(--t-fast);
}

.modal-close-btn:hover { background: var(--light-2); color: var(--navy); }
.modal-close-btn:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

.modal-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--navy);
  margin-bottom: var(--sp-xs);
}

.modal-subtitle {
  font-size: 0.875rem;
  color: var(--text-soft);
  margin-bottom: var(--sp-lg);
}

.modal-options {
  display: flex;
  flex-direction: column;
  gap: var(--sp-md);
}

.modal-option {
  display: flex;
  align-items: center;
  gap: var(--sp-md);
  border-radius: var(--r-lg);
  padding: var(--sp-md) var(--sp-lg);
  border: 2px solid transparent;
  transition: all var(--t-med);
  cursor: pointer;
}

.modal-option-ta {
  background: rgba(16,185,129,0.07);
  border-color: rgba(16,185,129,0.25);
}

.modal-option-ta:hover {
  background: rgba(16,185,129,0.13);
  border-color: var(--teal);
  transform: translateX(4px);
}

.modal-option-toan {
  background: rgba(245,158,11,0.07);
  border-color: rgba(245,158,11,0.25);
}

.modal-option-toan:hover {
  background: rgba(245,158,11,0.13);
  border-color: var(--amber);
  transform: translateX(4px);
}

.modal-opt-icon { font-size: 2rem; flex-shrink: 0; }

.modal-opt-content { flex: 1; }

.modal-opt-content h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 0.15rem;
}

.modal-opt-content p {
  font-size: 0.8rem;
  color: var(--text-soft);
  margin-bottom: 0.3rem;
}

.modal-zoom-codes {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-sm);
  font-size: 0.78rem;
}

.modal-zoom-codes span {
  background: rgba(15,43,70,0.06);
  border-radius: var(--r-sm);
  padding: 0.15rem 0.5rem;
  color: var(--text-soft);
}

.modal-zoom-codes strong { color: var(--navy); }

.modal-arrow {
  font-size: 1.2rem;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: transform var(--t-fast), color var(--t-fast);
}

.modal-option:hover .modal-arrow {
  transform: translateX(3px);
  color: var(--navy);
}


/* ==========================================================================
   16. ADDITIONAL RESPONSIVE TWEAKS
   ========================================================================== */

/* Very small screens */
@media (max-width: 360px) {
  .hero-heading { font-size: 1.7rem; }
  .hero-btns .btn { padding: 0.7rem 1.2rem; font-size: 0.88rem; }
  .stat-sep { display: none; }
  .hero-stats { gap: var(--sp-md); }
}

/* Container padding on larger screens */
@media (min-width: 1024px) {
  .container { padding: 0 var(--sp-xl); }
}

/* Smooth transition for all layout changes */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  [data-animate] {
    opacity: 1;
    transform: none;
  }
}