/* ============================================================
   1000GENZER - DESIGN SYSTEM & REFINED STYLESHEET
   Aesthetics: Modern Clean Light Mode, Solid High Contrast, 0% Glassmorphism
   ============================================================ */

:root {
  --bg-main: #f8fafc;
  --bg-surface: #ffffff;
  --bg-subtle: #f1f5f9;
  --bg-dark: #0f172a;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --text-white: #ffffff;

  --brand-primary: #1e40af;
  --brand-primary-hover: #1d4ed8;
  --brand-accent: #059669;
  --brand-highlight: #d97706;

  --border-color: #e2e8f0;
  --border-color-dark: #cbd5e1;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 10px 25px rgba(15, 23, 42, 0.1);

  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --container-max: 1200px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  background-color: var(--bg-main);
}

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

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

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

/* Minimalist Single-Line Header (Tối giản 1 dòng) */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px; /* Gọn gàng 64px */
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--brand-primary);
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.logo__badge {
  background-color: var(--brand-accent);
  color: #fff;
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  text-transform: uppercase;
}

.nav {
  display: flex;
  align-items: center;
  gap: 24px;
  white-space: nowrap;
}

.nav__link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.2s;
}

.nav__link:hover {
  color: var(--brand-primary);
}

/* Solid Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}

.btn--primary {
  background-color: var(--brand-primary);
  color: var(--text-white);
}

.btn--primary:hover {
  background-color: var(--brand-primary-hover);
  transform: translateY(-1px);
}

.btn--outline {
  background-color: var(--bg-surface);
  color: var(--text-main);
  border-color: var(--border-color-dark);
}

.btn--outline:hover {
  background-color: var(--bg-subtle);
  border-color: var(--text-main);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
}

.badge--blue { background: #dbeafe; color: #1e40af; }
.badge--green { background: #d1fae5; color: #065f46; }
.badge--amber { background: #fef3c7; color: #92400e; }
.badge--dark { background: #0f172a; color: #ffffff; }

/* Hero Component */
.hero {
  padding: 48px 0 64px;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
}

.hero__inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}

.hero__h1 {
  font-size: 2.75rem;
  line-height: 1.15;
  font-weight: 800;
  margin: 16px 0;
  letter-spacing: -0.02em;
}

.hero__desc {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 28px;
}

.hero__stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.hero__stat {
  text-align: center;
  background-color: var(--bg-subtle);
  padding: 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.hero__stat-val {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--brand-primary);
  display: block;
}

.hero__stat-lbl {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 600;
}

/* Sections */
.section {
  padding: 80px 0;
}

.section--alt {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-title {
  font-size: 2rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 12px;
}

.section-sub {
  text-align: center;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 48px;
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-color-dark);
}

/* Skill & Timeline Styles (Lấy từ phanhuynhanh.com) */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.skill-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 16px;
  border-radius: var(--radius-md);
}

.skill-bar {
  height: 8px;
  background: var(--bg-subtle);
  border-radius: 4px;
  margin-top: 8px;
  overflow: hidden;
}

.skill-bar-fill {
  height: 100%;
  background: var(--brand-primary);
  border-radius: 4px;
}

/* Modal Styling */
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.7);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal.active { display: flex; }

.modal__content {
  background: var(--bg-surface);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 800px;
  max-height: 90vh;
  overflow-y: auto;
  padding: 32px;
  border: 1px solid var(--border-color-dark);
}

/* Footer */
.footer {
  background-color: var(--bg-dark);
  color: var(--text-white);
  padding: 48px 0 24px;
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #334155;
  padding-bottom: 24px;
  margin-bottom: 24px;
}

@media (max-width: 900px) {
  .hero__inner { grid-template-columns: 1fr; }
  .cards-grid, .skills-grid { grid-template-columns: 1fr; }
  .hero__stats-strip { grid-template-columns: 1fr 1fr; }
  .nav { display: none; }
}