/* ==========================================================================
   NAM PHUONG STORE - STYLE SHEET (MOBILE-FIRST & REALISTIC GLASSMORPHISM)
   File: css/style.css
   Mô tả: Hệ màu trầm graphite sang trọng, typography Inter, layout mobile-first.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS VARIABLES (:ROOT) - DESIGN SYSTEM SANG TRỌNG & THỰC TẾ
   -------------------------------------------------------------------------- */
:root {
  /* Nền tối sâu (Deep Black & Dark Graphite) - Giảm tím/neon, tăng độ đầm */
  --bg-primary: #08090d;
  --bg-secondary: #0e1117;
  --bg-tertiary: #141822;
  --bg-surface: #1a202c;

  /* Kính mờ thực tế (Realistic Glassmorphism) - Dày dặn, cao cấp */
  --card-bg: rgba(18, 22, 33, 0.85);
  --card-bg-hover: rgba(25, 31, 46, 0.95);
  --card-border: rgba(255, 255, 255, 0.08);
  --card-border-hover: rgba(255, 255, 255, 0.18);

  /* Màu nhấn Pastel / Tinh tế (De-saturated, giảm lòe loẹt) */
  --accent-cyan: #38bdf8;
  --accent-cyan-subtle: rgba(56, 189, 248, 0.12);
  --accent-blue: #3b82f6;
  --accent-purple: #818cf8;
  --accent-green: #34d399;
  --accent-amber: #fbbf24;
  --accent-slate: #94a3b8;

  /* Typography - Inter Sans-serif hiện đại, nghiêm túc */
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Màu chữ phân cấp */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-white: #ffffff;

  /* Gradients tinh tế (Bạc sáng sang Cyan Pastel nhẹ) */
  --gradient-text: linear-gradient(180deg, #ffffff 40%, #cbd5e1 100%);
  --gradient-accent-text: linear-gradient(135deg, #ffffff 20%, #38bdf8 80%);
  --gradient-card: linear-gradient(180deg, rgba(255, 255, 255, 0.03) 0%, rgba(255, 255, 255, 0.01) 100%);

  /* Đổ bóng thực tế */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px -8px rgba(0, 0, 0, 0.7);
  --shadow-card: 0 10px 30px -5px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.08);

  /* Bo góc */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 26px;
  --radius-full: 9999px;

  /* Chuyển động */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Ánh glow nhẹ ở góc (giảm cường độ, cực kỳ mờ và êm mắt) */
body::before {
  content: '';
  position: fixed;
  top: -150px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse at center, rgba(56, 189, 248, 0.06) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  filter: blur(80px);
}

/* --------------------------------------------------------------------------
   3. TYPOGRAPHY & UTILITIES
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
  letter-spacing: -0.025em;
}

p {
  color: var(--text-secondary);
}

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

ul, ol {
  list-style: none;
}

img, svg {
  display: block;
  max-width: 100%;
}

/* Container Responsive */
.container {
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
  position: relative;
  z-index: 2;
}

@media (min-width: 640px) {
  .container {
    max-width: 640px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 768px;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 1040px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1160px;
  }
}

/* Tiêu đề & Gradient chữ tinh tế */
.text-gradient {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-accent-gradient {
  background: var(--gradient-accent-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.text-green {
  color: var(--accent-green);
}

/* Badge tinh gọn, trang nhã */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
}

.badge--cyan {
  background: var(--accent-cyan-subtle);
  border-color: rgba(56, 189, 248, 0.25);
  color: var(--accent-cyan);
}

.badge--green {
  background: rgba(52, 211, 153, 0.1);
  border-color: rgba(52, 211, 153, 0.25);
  color: var(--accent-green);
}

/* Hệ thống Nút Bấm Thực Tế */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  font-family: var(--font-main);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
  white-space: nowrap;
  touch-action: manipulation;
}

.btn-primary {
  background: #ffffff;
  color: #090a0f;
  border: 1px solid #ffffff;
  box-shadow: 0 4px 12px rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  background: #e2e8f0;
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.12);
  color: var(--text-primary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.btn-zalo {
  background: #0068ff;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 4px 14px rgba(0, 104, 255, 0.3);
}

.btn-zalo:hover {
  background: #0058db;
  box-shadow: 0 6px 20px rgba(0, 104, 255, 0.45);
  transform: translateY(-1px);
}

.btn-telegram {
  background: rgba(34, 158, 217, 0.15);
  border-color: rgba(34, 158, 217, 0.35);
  color: #38bdf8;
}

.btn-telegram:hover {
  background: rgba(34, 158, 217, 0.25);
  border-color: #38bdf8;
}

.btn-lg {
  padding: 0.95rem 1.8rem;
  font-size: 1rem;
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
}

/* --------------------------------------------------------------------------
   4. NAVBAR (MOBILE-FIRST)
   -------------------------------------------------------------------------- */
.navbar {
  position: sticky;
  top: 0;
  width: 100%;
  background: rgba(8, 9, 13, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  z-index: 100;
  transition: background var(--transition-fast);
}

.navbar--scrolled {
  background: rgba(8, 9, 13, 0.95);
  border-bottom-color: rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
}

.navbar__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

/* Brand Logo */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.brand-logo__icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--accent-cyan);
}

.brand-logo__highlight {
  color: var(--accent-cyan);
  font-weight: 500;
}

/* Menu điều hướng trên Mobile: Mặc định ẩn, bật lên dưới dạng Side-drawer/Full-screen */
.nav-menu {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 280px;
  max-width: 85vw;
  background: #0d1017;
  border-left: 1px solid rgba(255, 255, 255, 0.1);
  padding: 5rem 1.8rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  z-index: 150;
  box-shadow: -10px 0 30px rgba(0, 0, 0, 0.8);
}

.nav-menu.is-active {
  transform: translateX(0);
}

/* Backdrop mờ khi mở mobile menu */
.nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 140;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.nav-backdrop.is-active {
  opacity: 1;
  visibility: visible;
}

.nav-link {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.4rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
  transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link:active {
  color: #ffffff;
}

.navbar__actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

/* Nút Hamburger Menu */
.menu-toggle {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 160;
  transition: all var(--transition-fast);
}

.menu-toggle:hover {
  background: rgba(255, 255, 255, 0.12);
}

/* Desktop Navbar Breakpoint (>= 1024px) */
@media (min-width: 1024px) {
  .navbar__container {
    height: 72px;
  }

  .menu-toggle {
    display: none;
  }

  .nav-backdrop {
    display: none !important;
  }

  .nav-menu {
    position: static;
    width: auto;
    max-width: none;
    background: transparent;
    border-left: none;
    padding: 0;
    flex-direction: row;
    align-items: center;
    gap: 2.2rem;
    transform: none;
    box-shadow: none;
    z-index: auto;
  }

  .nav-link {
    font-size: 0.92rem;
    padding: 0.4rem 0;
    border-bottom: none;
  }

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

/* --------------------------------------------------------------------------
   5. HERO SECTION (MOBILE-FIRST VERTICAL LAYOUT)
   -------------------------------------------------------------------------- */
.hero-section {
  position: relative;
  padding: 2.5rem 0 3.5rem;
  overflow: hidden;
}

.hero-grid {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2.5rem;
  text-align: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  max-width: 680px;
}

.hero-title {
  font-size: 2.1rem;
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.hero-description {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  width: 100%;
  gap: 0.75rem;
  margin-top: 0.25rem;
}

.hero-actions .btn {
  width: 100%;
}

/* Thống kê niềm tin trên mobile */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  width: 100%;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
}

.stat-number {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Tablet & Desktop Hero */
@media (min-width: 640px) {
  .hero-actions {
    flex-direction: row;
    justify-content: center;
    width: auto;
  }

  .hero-actions .btn {
    width: auto;
  }
}

@media (min-width: 1024px) {
  .hero-section {
    padding: 4.5rem 0 5rem;
  }

  .hero-grid {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    text-align: left;
    align-items: center;
    gap: 3.5rem;
  }

  .hero-content {
    align-items: flex-start;
  }

  .hero-title {
    font-size: 3.25rem;
  }

  .hero-description {
    font-size: 1.12rem;
  }

  .hero-stats {
    width: 100%;
    max-width: 480px;
    gap: 1.5rem;
  }

  .stat-item {
    align-items: flex-start;
  }

  .stat-number {
    font-size: 1.6rem;
  }
}

/* --------------------------------------------------------------------------
   6. SECTION HEADERS CHUNG
   -------------------------------------------------------------------------- */
.section {
  padding: 4rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 2.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.section-title {
  font-size: 1.85rem;
  letter-spacing: -0.02em;
}

.section-description {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

@media (min-width: 768px) {
  .section {
    padding: 5.5rem 0;
  }

  .section-header {
    margin-bottom: 3.5rem;
  }

  .section-title {
    font-size: 2.25rem;
  }

  .section-description {
    font-size: 1.05rem;
  }
}

/* --------------------------------------------------------------------------
   7. FEATURES SECTION (TÍNH NĂNG - 1 CỘT TRÊN MOBILE)
   -------------------------------------------------------------------------- */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.feature-card:hover {
  background: var(--card-bg-hover);
  border-color: var(--card-border-hover);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.6);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.09);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
}

.feature-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

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

@media (min-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
  }
}

/* --------------------------------------------------------------------------
   8. PRICING & FAQ WRAPPERS
   -------------------------------------------------------------------------- */
.pricing-section {
  position: relative;
}

.pricing-container {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
}

.faq-layout {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 820px;
  margin: 0 auto;
}

/* --------------------------------------------------------------------------
   9. FOOTER (MOBILE-FIRST VERTICAL)
   -------------------------------------------------------------------------- */
.footer {
  background: #050609;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 3.5rem 0 2rem;
  position: relative;
  z-index: 10;
}

.footer-grid {
  display: flex;
  flex-direction: column;
  gap: 2.25rem;
  margin-bottom: 2.5rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.footer-brand-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 360px;
}

.footer-heading {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.85rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-link {
  color: var(--text-secondary);
  font-size: 0.92rem;
  padding: 0.25rem 0;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: #ffffff;
}

.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.footer-contact-item {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
  min-height: 38px;
}

.footer-bottom {
  padding-top: 1.8rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.65rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

@media (min-width: 768px) {
  .footer-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 2.5rem;
  }

  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}