/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Icon Styles */
.icon-large {
    font-size: 3rem;
    color: #667eea;
    margin-bottom: 1rem;
    display: block;
    text-align: center;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #1a202c;
    overflow-x: hidden;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 50%, #4facfe 100%);
    background-attachment: fixed;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    position: relative; /* Added position relative for dropdown */
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1a365d;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #4a5568;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #2b6cb0;
}

/* Hero Section */
.hero {
    height: 110vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.hero-content {
    text-align: center;
    z-index: 2;
    max-width: 800px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #ffffff;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease-out 0.2s both;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 1s ease-out 0.4s both;
}

.btn {
    padding: 1rem 2rem;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: #2b6cb0;
    border: 2px solid #2b6cb0;
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: #2b6cb0;
    color: white;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /*background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);*/
    animation: gradientShift 8s ease infinite;
    z-index: 1;
      background:
    linear-gradient(
      135deg,
      rgba(236, 72, 153, 0.65),
      rgba(168, 85, 247, 0.65)
    ),
    url("Images/webdesign.jpg") center / cover no-repeat;
    /*background-image: url("Images/web-designer.jpg");
    background-repeat: no-repeat;*/
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="%23ffffff" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="%23ffffff" opacity="0.1"/><circle cx="50" cy="10" r="0.5" fill="%23ffffff" opacity="0.05"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

/* LỚP PHỦ MÀU HỒNG – TÍM */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(236, 72, 153, 0.65),   /* pink */
    rgba(168, 85, 247, 0.65)    /* purple */
  );
  z-index: 1;
}

/* Nội dung nằm trên overlay */
.hero-content {
  position: relative;
  z-index: 2;
  color: white;
  text-align: center;
}

/* Sections */
.section {
    padding: 5rem 0;
    position: relative;
}

.section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    color: #1a365d;
}

.about {
    background: #f7fafc;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: rgba(255, 255, 255, 0.97);
        backdrop-filter: blur(10px);
        width: 100%;
        text-align: center;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.08);
        padding: 0;
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        pointer-events: none;
        transition: max-height 0.3s ease, opacity 0.3s ease;
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(31, 38, 135, 0.5);
}

.about-card h3 {
    color: #2b6cb0;
    margin-bottom: 1rem;
}


/* Format */
.format-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.format-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
    text-align: center;
    transition: transform 0.3s ease;
}

.format-card:hover {
    transform: translateY(-5px);
}

.format-card h3 {
    color: #2b6cb0;
    margin-bottom: 1rem;
}

.format-card ul {
    list-style: none;
    padding: 0;
}

.format-card li {
    margin-bottom: 0.5rem;
}

/* Training */
.training-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.speaker-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
    text-align: center;
    transition: transform 0.3s ease;
}

.speaker-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(31, 38, 135, 0.5);
}

.speaker-avatar {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    margin: 0 auto 1rem;
}

.speaker-card h3 {
    color: #2b6cb0;
    margin-bottom: 1rem;
}

/* Evaluation */
.criteria-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.criteria-item {
    text-align: center;
}

.criteria-item h3 {
    color: #2b6cb0;
    margin-bottom: 1rem;
}

.progress-bar {
    width: 100%;
    height: 20px;
    background: #e2e8f0;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    transition: width 1s ease;
}

/* Prizes */
.prizes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.prize-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
    text-align: center;
    transition: transform 0.3s ease;
}

.prize-card:hover {
    transform: translateY(-5px);
}

.prize-card h3 {
    color: #2b6cb0;
    margin-bottom: 1rem;
}

.prize-amount {
    font-size: 1.5rem;
    font-weight: 700;
    color: #38a169;
}

/* Organizers */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.organizer-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
    text-align: center;
    transition: transform 0.3s ease;
}

.organizer-card:hover {
    transform: translateY(-5px);
}

.organizer-card h3 {
    color: #2b6cb0;
}

/* CTA */
.cta {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta h2 {
    color: white;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.contact-info {
    margin-top: 2rem;
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Footer */
.footer {
    background: #1a365d;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Chatbot */
.chatbot {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
}

.chatbot-toggle {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.5rem;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    transition: transform 0.3s ease;
}

.chatbot-toggle:hover {
    transform: scale(1.1);
}

.chatbot-window {
    position: absolute;
    bottom: 80px;
    right: 0;
    width: 300px;
    height: 400px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    display: none;
    flex-direction: column;
    overflow: hidden;
}

.chatbot-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem;
    font-weight: 600;
}

.chatbot-messages {
    flex: 1;
    padding: 1rem;
    overflow-y: auto;
}

.chatbot-input {
    border: none;
    border-top: 1px solid #e2e8f0;
    padding: 1rem;
    outline: none;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 3rem;
    }

    .hero-subtitle {
        font-size: 1.3rem;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .countdown {
        gap: 0.5rem;
    }

    .countdown-item {
        min-width: 60px;
        padding: 0.8rem;
    }

    .countdown-number {
        font-size: 1.5rem;
    }

    .hamburger {
        display: flex;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: rgba(255, 255, 255, 0.97);
        backdrop-filter: blur(10px);
        width: 100%;
        text-align: center;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.08);
        padding: 0;
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        pointer-events: none;
        transition: max-height 0.3s ease, opacity 0.3s ease;
    }

    .nav-links.active {
        max-height: 420px;
        opacity: 1;
        pointer-events: auto;
    }

    .nav-links li {
        margin: 1.25rem 0;
    }

    .timeline-container::before {
        left: 30px;
    }

    .timeline-item {
        justify-content: flex-start !important;
        margin-left: 60px;
    }

    .timeline-item::before {
        left: -40px;
    }

    .timeline-item .timeline-content {
        margin-left: 0 !important;
        margin-right: 0 !important;
    }

    .section {
        padding: 3rem 0;
    }

    .section h2 {
        font-size: 2rem;
    }

    .about-grid, .format-grid, .training-grid, .prizes-grid, .organizers-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .criteria-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .btn {
        padding: 0.8rem 1.5rem;
        font-size: 1rem;
    }

    .container {
        padding: 0 15px;
    }

    .criteria-grid {
        grid-template-columns: 1fr;
    }
}

/* Countdown Timer */
.countdown {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.countdown-item {
    text-align: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 1rem;
    border-radius: 10px;
    min-width: 80px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.countdown-number {
    font-size: 2rem;
    font-weight: 700;
    color: #ffffff;
    display: block;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.countdown-label {
    font-size: 0.9rem;
    color: #ffffff;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 0.5rem;
}

.countdown-expired {
    font-size: 1.5rem;
    color: #ff6b6b;
    text-align: center;
    font-weight: 600;
}

/* Enhanced Button Glow */
.btn-glow {
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    }
    to {
        box-shadow: 0 4px 25px rgba(102, 126, 234, 0.8), 0 0 30px rgba(102, 126, 234, 0.4);
    }
}

/* Hamburger Menu */
.hamburger {
    /*display: none;*/
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
    width: 40px;
    height: 30px;
    justify-content: center;
    align-items: center;
    padding: 5px;
    box-sizing: border-box;
}

.hamburger span {
    width: 30px;
    height: 4px;
    background: #1a365d;
    transition: 0.3s;
    border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -5px);
}

/* Scroll Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.navbar .container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px 24px;

  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  display: flex;
  align-items: center;
}

.logo img {
  height: 90px;          /* chỉnh theo ý */
  width: auto;

  border-radius: 10px;  /* BO GÓC */
  padding: 2px;
  background: #fff;

  box-shadow: 0 6px 6px rgba(0, 0, 0, 0.15);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

/* Hover nhẹ cho đẹp */
.logo img:hover {
  transform: scale(1.05);
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.25);
}
.nav-links {
  list-style: none;
  display: flex;
  gap: 28px;
  margin: 0;
  padding: 0;
}

.nav-links li a {
  text-decoration: none;
  font-weight: 600;
  color: #333;
  position: relative;
}

/* underline animation */
.nav-links li a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  background: #ff6a00;
  transition: width 0.3s ease;
}

.nav-links li a:hover::after {
  width: 100%;
}
@media (max-width: 992px) {
  .nav-links {
    position: absolute;
    top: 70px;
    right: 24px;
    flex-direction: column;
    background: white;
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
    display: none;
  }

  .nav-links.active {
    display: flex;
  }
}

/* ====== SECTION ====== */
#timeline.section.timeline {
  padding: 80px 0;
  background: #fff;
}

#timeline .container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

#timeline h2 {
  text-align: center;
  font-size: clamp(28px, 3vw, 44px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #0f172a;
  margin: 0 0 50px;
}

/* ====== TIMELINE WRAP ====== */
.timeline-container {
  position: relative;
  padding: 10px 0;
}

/* center line */
.timeline-container::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 3px;
  transform: translateX(-50%);
  background: linear-gradient(
    to bottom,
    rgba(168, 85, 247, 0.15),
    rgba(236, 72, 153, 0.25),
    rgba(59, 130, 246, 0.15)
  );
  border-radius: 999px;
}

/* ====== ITEM ====== */
.timeline-item {
  position: relative;
  display: flex;
  align-items: stretch;
  gap: 22px;
  margin: 22px 0;
}

/* alternate left/right */
.timeline-item:nth-child(odd) {
  flex-direction: row-reverse;
}

/* dot on center line */
.timeline-item::before {
  content: "";
  position: absolute;
  top: 24px;
  left: 50%;
  width: 14px;
  height: 14px;
  transform: translateX(-50%);
  border-radius: 999px;
  background: #fff;
  border: 3px solid rgba(168, 85, 247, 0.95);
  box-shadow: 0 10px 25px rgba(0,0,0,.12);
  z-index: 3;
}

/* ====== DATE BOX ====== */
.timeline-date {
  flex: 0 0 200px; /* độ rộng khối ngày */
  padding: 14px 16px;
  border-radius: 18px;
  color: #fff;
  font-weight: 800;
  font-size: 15px;
  line-height: 1.2;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  text-align: center;

  background: linear-gradient(135deg, #a855f7, #ec4899);
  box-shadow: 0 14px 34px rgba(168, 85, 247, 0.25);
}

/* nhỏ hơn 1 chút cho date range dài */
.timeline-date small {
  opacity: 0.9;
  font-weight: 700;
}

/* ====== CONTENT CARD ====== */
.timeline-content {
  flex: 1;
  background: rgba(255,255,255,0.92);
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 18px;
  padding: 18px 20px;
  box-shadow: 0 16px 40px rgba(2, 6, 23, 0.08);
  backdrop-filter: blur(6px);
  position: relative;
}

/* subtle highlight bar */
.timeline-content::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 5px;
  border-radius: 999px;
  background: linear-gradient(180deg, #a855f7, #ec4899);
  opacity: 0.85;
}

.timeline-content h3 {
  margin: 0 0 6px;
  padding-left: 10px;
  font-size: 22px;
  font-weight: 800;
  color: #0f172a;
}

.timeline-content p {
  margin: 0;
  padding-left: 10px;
  color: rgba(15, 23, 42, 0.75);
  font-size: 15px;
  line-height: 1.6;
}

/* hover nhẹ cho “đã mắt” */
.timeline-item:hover .timeline-content {
  transform: translateY(-2px);
  transition: transform .2s ease, box-shadow .2s ease;
  box-shadow: 0 22px 55px rgba(2, 6, 23, 0.12);
}

/* ====== RESPONSIVE ====== */
@media (max-width: 900px) {
  .timeline-container::before {
    left: 18px;
    transform: none;
  }

  .timeline-item,
  .timeline-item:nth-child(odd) {
    flex-direction: column;
    padding-left: 40px;
    gap: 12px;
  }

  .timeline-item::before {
    left: 18px;
    transform: none;
  }

  .timeline-date {
    flex: none;
    width: fit-content;
    max-width: 100%;
    justify-content: flex-start;
    padding: 10px 14px;
    border-radius: 999px; /* pill on mobile */
    font-size: 14px;
  }
}