/* ==========================================================================
   LANDING PAGE STYLES & RICH ANIMATIONS
   DIỄN ĐÀN ĐỔI MỚI SÁNG TẠO GIÁO DỤC VỚI TRÍ TUỆ NHÂN TẠO 2026
   Tác giả: Phan Thị Hoài Hạ - Giáo viên Trường THCS Đức Thọ
   ========================================================================== */

/* Keyframe Animations */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-16px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(22px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes cardFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4), 0 0 16px rgba(99, 102, 241, 0.2); }
  50% { box-shadow: 0 16px 44px rgba(0, 0, 0, 0.5), 0 0 28px rgba(99, 102, 241, 0.5), 0 0 12px rgba(56, 189, 248, 0.35); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes subtleBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Utility Helpers */
.hidden {
  display: none !important;
}

/* Responsive Helper */
@media (max-width: 900px) {
  .hidden-mobile {
    display: none !important;
  }
}

/* Top Competition Banner */
.top-notice-bar {
  background: linear-gradient(90deg, #1e1b4b, #312e81, #0f172a);
  border-bottom: 1px solid rgba(99, 102, 241, 0.35);
  color: #c7d2fe;
  padding: 0.65rem 1rem;
  font-size: 0.85rem;
  text-align: center;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  animation: fadeInDown 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.top-notice-badge {
  background: rgba(99, 102, 241, 0.25);
  color: #a5b4fc;
  border: 1px solid rgba(99, 102, 241, 0.4);
  padding: 0.2rem 0.65rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* Landing Hero Section */
.landing-hero {
  padding: 4rem 0 3rem;
  text-align: center;
  position: relative;
}

.hero-badges-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1.75rem;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.1s both;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(30, 41, 59, 0.75);
  border: 1px solid rgba(255, 255, 255, 0.14);
  color: #e2e8f0;
  padding: 0.4rem 1rem;
  border-radius: 9999px;
  font-size: 0.82rem;
  font-weight: 600;
  backdrop-filter: blur(10px);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hero-pill:hover {
  transform: translateY(-2px);
}

.hero-pill.pill-primary {
  border-color: rgba(99, 102, 241, 0.5);
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
}

.hero-pill.pill-gold {
  border-color: rgba(245, 158, 11, 0.5);
  background: rgba(245, 158, 11, 0.15);
  color: #fde68a;
}

.hero-pill.pill-green {
  border-color: rgba(16, 185, 129, 0.5);
  background: rgba(16, 185, 129, 0.15);
  color: #6ee7b7;
}

.landing-title {
  font-size: clamp(1.85rem, 4.5vw, 3rem);
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.2s both;
}

.landing-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-muted);
  max-width: 860px;
  margin: 0 auto 2.25rem;
  line-height: 1.7;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.3s both;
}

/* Author Spotlight Card in Hero */
.author-spotlight-card {
  display: inline-flex;
  align-items: center;
  gap: 1.25rem;
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(99, 102, 241, 0.4);
  padding: 0.85rem 1.75rem;
  border-radius: 9999px;
  margin-bottom: 2.5rem;
  backdrop-filter: blur(16px);
  text-align: left;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.4s both, pulseGlow 5s ease-in-out infinite, cardFloat 4s ease-in-out 1.2s infinite;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.author-spotlight-card:hover {
  border-color: #38bdf8;
  transform: translateY(-8px) scale(1.02);
}

.author-avatar-circle {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, #6366f1, #06b6d4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  border: 2px solid rgba(255, 255, 255, 0.3);
  flex-shrink: 0;
  transition: transform 0.3s ease;
}

.author-spotlight-card:hover .author-avatar-circle {
  transform: rotate(6deg) scale(1.08);
}

.author-info-meta {
  display: flex;
  flex-direction: column;
}

.author-name-tag {
  font-size: 1.05rem;
  font-weight: 800;
  color: #ffffff;
}

.author-school-tag {
  font-size: 0.85rem;
  color: #38bdf8;
  font-weight: 600;
}

/* Hero Action CTA Buttons */
.landing-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 3rem;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.5s both;
}

.btn-landing-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  background: linear-gradient(135deg, #6366f1, #4f46e5);
  color: #ffffff;
  padding: 0.95rem 1.85rem;
  border-radius: 12px;
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.35);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn-landing-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 34px rgba(99, 102, 241, 0.55);
  background: linear-gradient(135deg, #4f46e5, #4338ca);
}

.btn-landing-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  background: rgba(30, 41, 59, 0.75);
  color: #e2e8f0;
  padding: 0.95rem 1.85rem;
  border-radius: 12px;
  font-weight: 600;
  font-size: 1.05rem;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.12);
  transition: var(--transition-normal);
}

.btn-landing-secondary:hover {
  background: rgba(51, 65, 85, 0.9);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

/* Metrics Section with Staggered Entrance */
.metrics-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-bottom: 4.5rem;
  animation: fadeInUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.6s both;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 1.75rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(12px);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.3s ease, box-shadow 0.3s ease;
}

.metric-card:hover {
  border-color: rgba(99, 102, 241, 0.6);
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4), 0 0 20px rgba(99, 102, 241, 0.25);
}

.metric-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #6366f1, #06b6d4, #10b981);
  background-size: 200% 200%;
  animation: gradientShift 4s ease infinite;
}

.metric-number {
  font-size: 2.75rem;
  font-weight: 900;
  color: #ffffff;
  line-height: 1.1;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #ffffff, #93c5fd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: transform 0.3s ease;
}

.metric-card:hover .metric-number {
  transform: scale(1.06);
}

.metric-label {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1.4;
}

/* Section Common Header */
.section-block {
  margin-bottom: 5rem;
}

.section-head {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 3rem;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: #38bdf8;
  margin-bottom: 0.65rem;
}

.section-title {
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  font-weight: 800;
  margin-bottom: 1rem;
  color: #ffffff;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 3-Column Problem Statement Grid */
.problems-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.problem-card {
  background: rgba(17, 24, 39, 0.7);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: var(--radius-lg);
  padding: 2rem 1.75rem;
  position: relative;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.3s ease, box-shadow 0.3s ease;
}

.problem-card:hover {
  border-color: rgba(239, 68, 68, 0.6);
  transform: translateY(-6px);
  box-shadow: 0 14px 32px rgba(239, 68, 68, 0.15);
}

.problem-card .icon-box {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  margin-bottom: 1.25rem;
  transition: transform 0.3s ease;
}

.problem-card:hover .icon-box {
  transform: scale(1.1) rotate(-6deg);
}

.problem-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: #ffffff;
}

.problem-card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Solutions & AI Features Grid */
.solutions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.solution-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem;
  position: relative;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.3s ease, box-shadow 0.3s ease;
  display: flex;
  flex-direction: column;
}

.solution-card:hover {
  border-color: rgba(99, 102, 241, 0.6);
  transform: translateY(-6px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4), 0 0 24px rgba(99, 102, 241, 0.2);
}

.solution-card .icon-box {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
  transition: transform 0.3s ease;
}

.solution-card:hover .icon-box {
  transform: scale(1.12);
}

.solution-card .icon-purple {
  background: rgba(99, 102, 241, 0.15);
  color: #818cf8;
}

.solution-card .icon-cyan {
  background: rgba(6, 182, 212, 0.15);
  color: #38bdf8;
}

.solution-card .icon-emerald {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
}

.solution-card .icon-amber {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
}

.solution-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: #ffffff;
}

.solution-card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.feature-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
}

.feature-tag-item {
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: #cbd5e1;
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  font-weight: 500;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.feature-tag-item:hover {
  background: rgba(99, 102, 241, 0.2);
  border-color: rgba(99, 102, 241, 0.4);
  color: #ffffff;
}

/* 4-Step Student Journey */
.journey-timeline {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  position: relative;
}

.journey-step-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  position: relative;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.3s ease;
}

.journey-step-card:hover {
  border-color: rgba(56, 189, 248, 0.5);
  transform: translateY(-5px);
}

.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, #6366f1, #06b6d4);
  color: #ffffff;
  font-weight: 800;
  font-size: 1.05rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 6px 16px rgba(99, 102, 241, 0.4);
  transition: transform 0.3s ease;
}

.journey-step-card:hover .step-badge {
  transform: scale(1.15) rotate(10deg);
}

.journey-step-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.65rem;
}

.journey-step-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Live Demo Interactive Showcase Banner */
.live-demo-banner {
  background: linear-gradient(135deg, rgba(30, 27, 75, 0.85), rgba(15, 23, 42, 0.95));
  border: 1px solid rgba(99, 102, 241, 0.4);
  border-radius: var(--radius-lg);
  padding: 3.5rem 2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.5), 0 0 30px rgba(99, 102, 241, 0.25);
}

.live-demo-banner h2 {
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 1rem;
}

.live-demo-banner p {
  font-size: 1.05rem;
  color: #cbd5e1;
  max-width: 720px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

.demo-buttons-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

/* Author Profile Section */
.author-profile-box {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 2rem;
  align-items: center;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.author-profile-box:hover {
  border-color: rgba(99, 102, 241, 0.5);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4), 0 0 24px rgba(99, 102, 241, 0.2);
  transform: translateY(-4px);
}

@media (max-width: 768px) {
  .author-profile-box {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .author-photo-wrapper {
    margin: 0 auto;
  }
}

.author-photo-wrapper {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: linear-gradient(135deg, #6366f1, #38bdf8);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  box-shadow: 0 10px 25px rgba(99, 102, 241, 0.35);
  border: 3px solid rgba(255, 255, 255, 0.25);
  transition: transform 0.3s ease;
}

.author-profile-box:hover .author-photo-wrapper {
  transform: scale(1.05);
}

.author-details h3 {
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 0.35rem;
}

.author-subtitle {
  color: #38bdf8;
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.author-bio {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1.25rem;
}

.author-commitments {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.commitment-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: #a7f3d0;
  font-size: 0.82rem;
  padding: 0.35rem 0.75rem;
  border-radius: 9999px;
  font-weight: 500;
  transition: transform 0.2s ease;
}

.commitment-chip:hover {
  transform: translateY(-2px);
}

/* Footer Section */
.landing-footer {
  border-top: 1px solid var(--border-glass);
  padding: 3rem 0;
  margin-top: 4rem;
  color: var(--text-dim);
  font-size: 0.9rem;
  text-align: center;
  line-height: 1.6;
}

.landing-footer a {
  color: #94a3b8;
  text-decoration: underline;
}

.landing-footer a:hover {
  color: #ffffff;
}