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

:root {
  --bg-dark: #0f172a;
  --bg-card: #1e293b;
  --bg-alt: #131d35;
  --border-color: rgba(255, 255, 255, 0.08);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent-cyan: #38bdf8;
  --accent-indigo: #818cf8;
  --accent-violet: #a855f7;
  --accent-gold: #fbbf24;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  position: relative;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   Typography & Shared Utilities
   ========================================================================== */
.gradient-text {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-indigo), var(--accent-violet));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section {
  padding: 90px 0;
}

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

.section-header {
  text-align: center;
  max-width: 650px;
  margin: 0 auto 50px auto;
}

.section-tag {
  display: inline-block;
  padding: 4px 14px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 50px;
  margin-bottom: 12px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
  margin-bottom: 10px;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* ==========================================================================
   Header & Navbar
   ========================================================================== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

.nav-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  text-decoration: none;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-symbol {
  color: var(--accent-cyan);
  font-family: monospace;
}

.logo-text span {
  color: var(--accent-cyan);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--accent-cyan);
}

.btn-contact-nav {
  padding: 8px 18px !important;
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent-cyan) !important;
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: var(--radius-sm);
}

.btn-contact-nav:hover {
  background: var(--accent-cyan) !important;
  color: #000 !important;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 130px 0 100px 0;
  text-align: center;
  overflow: hidden;
}

.hero-bg-glow {
  position: absolute;
  top: 10%;
  left: 50%;
  transform: translateX(-50%);
  width: 550px;
  height: 350px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.18) 0%, rgba(129, 140, 248, 0.1) 40%, transparent 70%);
  filter: blur(80px);
  z-index: 0;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-radius: 50px;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  background-color: #22c55e;
  border-radius: 50%;
  box-shadow: 0 0 10px #22c55e;
}

.hero-title {
  font-size: 3.4rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -1px;
  margin-bottom: 20px;
}

.hero-subtitle {
  max-width: 680px;
  margin: 0 auto 36px auto;
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.hero-subtitle strong {
  color: var(--text-main);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: var(--transition);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-indigo));
  color: #0f172a;
  box-shadow: 0 8px 25px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(56, 189, 248, 0.45);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
}

/* ==========================================================================
   About Section
   ========================================================================== */
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 28px;
}

.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: var(--transition);
}

.about-card:hover {
  border-color: rgba(56, 189, 248, 0.3);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.about-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 14px;
}

.about-card p {
  color: var(--text-muted);
  line-height: 1.7;
}

.info-list {
  list-style: none;
}

.info-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.95rem;
  color: var(--text-muted);
}

.info-list li:last-child {
  border-bottom: none;
}

.info-list strong {
  color: var(--text-main);
  margin-right: 6px;
}

/* ==========================================================================
   Achievements Section
   ========================================================================== */
.achieve-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.achieve-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  position: relative;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

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

.achieve-card.gold:hover {
  border-color: rgba(251, 191, 36, 0.5);
  box-shadow: 0 10px 30px rgba(251, 191, 36, 0.12);
}

.achieve-card.silver:hover {
  border-color: rgba(203, 213, 225, 0.5);
  box-shadow: 0 10px 30px rgba(203, 213, 225, 0.12);
}

.achieve-card.bronze:hover {
  border-color: rgba(56, 189, 248, 0.5);
  box-shadow: 0 10px 30px rgba(56, 189, 248, 0.12);
}

.achieve-badge {
  position: absolute;
  top: 20px;
  right: 20px;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  color: var(--text-muted);
}

.achieve-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.achieve-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.achieve-field {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-cyan);
  margin-bottom: 12px;
}

.achieve-detail {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Skills Section
   ========================================================================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.skill-group {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
}

.skill-group h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
}

.tag:hover {
  background: rgba(56, 189, 248, 0.1);
  color: var(--accent-cyan);
  border-color: rgba(56, 189, 248, 0.3);
}

/* ==========================================================================
   Goals Section
   ========================================================================== */
.goals-wrapper {
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 800px;
  margin: 0 auto;
}

.goal-item {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: var(--transition);
}

.goal-item:hover {
  border-color: rgba(129, 140, 248, 0.4);
  transform: translateX(6px);
}

.goal-num {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent-indigo);
  opacity: 0.8;
  line-height: 1;
}

.goal-content h4 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.goal-content p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ==========================================================================
   Contact Section & Footer
   ========================================================================== */
.contact-box {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.9), rgba(19, 29, 53, 0.9));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 60px 24px;
  text-align: center;
  max-width: 750px;
  margin: 0 auto;
}

.contact-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 30px;
}

.contact-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--text-main);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
}

.contact-btn:hover {
  background: var(--accent-cyan);
  color: #0f172a;
  border-color: var(--accent-cyan);
}

.footer {
  padding: 32px 0;
  text-align: center;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */
@media (max-width: 900px) {
  .hero-title {
    font-size: 2.6rem;
  }
  .about-grid,
  .achieve-grid,
  .skills-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none; /* Rút gọn trên mobile cho tinh gọn */
  }
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-actions {
    flex-direction: column;
  }
  .goal-item {
    flex-direction: column;
    gap: 12px;
  }
}
/* Thu nhỏ và tạo hiệu ứng cho avatar */
.avatar-wrapper {
  width: 150px;
  height: 150px;
  margin: 0 auto 24px auto;
}

.avatar-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  border: 4px solid var(--accent-cyan);
  box-shadow: 0 0 25px rgba(56, 189, 248, 0.45);
  display: block;
}