/* ========== MAIN.CSS - Điện Lạnh Quang Trung 247 ========== */
/* CSS dùng chung cho Header, Footer và các thành phần tái sử dụng */

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700;900&display=swap');

:root {
  --primary: #00457c;
  --primary-dark: #0867A8;
  --primary-light: #E8F4FD;
  --primary-gradient: linear-gradient(135deg, #00457c 0%, #0867A8 100%);
  --secondary: #1A1A2E;
  --accent: #FF6B35;
  --accent-hover: #E85D2C;
  --light: #F8F9FA;
  --dark: #1A1A2E;
  --gray-100: #F7F8FA;
  --gray-200: #E9ECEF;
  --gray-300: #DEE2E6;
  --gray-600: #6C757D;
  --gray-800: #343A40;
  --white: #FFFFFF;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
  --shadow-xl: 0 12px 48px rgba(0,0,0,0.15);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --font-primary: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* ========== RESET & BASE ========== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-primary);
  font-weight: 400;
  color: var(--dark);
  background-color: var(--white);
  overflow-x: hidden;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.01em;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition-fast);
}

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

p {
  margin-bottom: 1rem;
  color: var(--gray-600);
}

/* ========== SCROLLBAR ========== */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--gray-100);
}
::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* ========== LOADING SCREEN ========== */
.loading-screen {
  position: fixed;
  inset: 0;
  background: var(--white);
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.5s, visibility 0.5s;
}
.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}
.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--gray-200);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ========== BACK TO TOP ========== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  background: var(--primary-gradient);
  color: var(--white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: var(--transition);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}
.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

/* ========== BUTTONS ========== */
.btn {
  font-family: var(--font-primary);
  font-weight: 600;
  border-radius: 50px;
  padding: 13px 32px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  border: none;
  letter-spacing: 0.3px;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.btn:active {
  transform: scale(0.96);
}
.btn-primary {
  background: var(--primary-gradient);
  border: none;
  color: var(--white);
  box-shadow: 0 4px 20px rgba(10, 127, 209, 0.3);
}
.btn-primary:hover {
  box-shadow: 0 8px 30px rgba(10, 127, 209, 0.5);
  transform: translateY(-3px);
  color: var(--white);
}
.btn-accent {
  background: var(--accent);
  color: var(--white);
  box-shadow: 0 4px 20px rgba(255, 107, 53, 0.3);
  font-weight: 700;
}
.btn-accent:hover {
  background: var(--accent-hover);
  box-shadow: 0 8px 30px rgba(255, 107, 53, 0.5);
  transform: translateY(-3px);
  color: var(--white);
}
.btn-outline-white {
  background: transparent;
  border: 2px solid rgba(255,255,255,0.8);
  color: var(--white);
  backdrop-filter: blur(10px);
}
.btn-outline-white:hover {
  background: var(--white);
  color: var(--primary);
  border-color: var(--white);
}
.btn-outline-primary {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}
.btn-outline-primary:hover {
  background: var(--primary);
  color: var(--white);
}
.btn-lg {
  padding: 16px 40px;
  font-size: 1.05rem;
  border-radius: 50px;
}
.btn-sm {
  padding: 10px 22px;
  font-size: 0.85rem;
}

/* ========== SECTION STYLES ========== */
.section-padding {
  padding: 100px 0;
}
.section-title {
  margin-bottom: 3.5rem;
}
.section-title .subtitle {
  display: inline-block;
  font-family: var(--font-primary);
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  color: var(--primary);
  margin-bottom: 0.75rem;
  position: relative;
  padding-left: 45px;
}
.section-title .subtitle::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 32px;
  height: 2.5px;
  background: var(--primary);
  border-radius: 2px;
}
.section-title h2 {
  font-size: 2.6rem;
  font-weight: 900;
  color: var(--dark);
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
}
.section-title .description {
  font-size: 1.1rem;
  color: var(--gray-600);
  max-width: 650px;
  line-height: 1.8;
}
.text-center .section-title .description {
  margin-left: auto;
  margin-right: auto;
}

/* ========== HEADER ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: var(--transition);
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  box-shadow: 0 2px 30px rgba(0,0,0,0.08);
  border-bottom-color: var(--gray-200);
}
.header-top {
  background: var(--dark);
  color: var(--white);
  font-size: 0.85rem;
  padding: 7px 0;
  transition: var(--transition);
  font-weight: 400;
}
.header-top a {
  color: rgba(255,255,255,0.85);
  font-weight: 400;
}
.header-top a:hover {
  color: var(--white);
}
.header-top .contact-info span {
  margin-right: 22px;
  font-weight: 400;
}
.header-top .contact-info i {
  color: var(--primary);
  margin-right: 7px;
  font-size: 0.8rem;
}
.header-top .social-links a {
  margin-left: 12px;
  width: 30px;
  height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(255,255,255,0.08);
  border-radius: 50%;
  transition: var(--transition-fast);
  font-size: 0.8rem;
}
.header-top .social-links a:hover {
  background: var(--primary);
  transform: translateY(-2px);
}

.header-main {
  padding: 6px 0;
  transition: var(--transition);
}
.header-main .navbar {
  padding: 0;
}
.header-main .navbar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.header-logo {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  object-fit: cover;
  box-shadow: 0 4px 12px rgba(10,127,209,0.2);
}
.header-brand-text {
  display: flex;
  flex-direction: column;
}
.header-brand-name {
  font-family: var(--font-primary);
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1.2;
  letter-spacing: -0.02em;
}
.header-brand-sub {
  font-family: var(--font-primary);
  font-size: 0.7rem;
  color: var(--gray-600);
  letter-spacing: 2px;
  text-transform: uppercase;
  font-weight: 500;
}

.navbar-nav {
  gap: 4px;
}
.navbar-nav .nav-link {
  font-family: var(--font-primary);
  color: var(--dark);
  font-weight: 600;
  padding: 10px 18px !important;
  border-radius: 50px;
  transition: var(--transition-fast);
  font-size: 0.95rem;
  position: relative;
  letter-spacing: -0.01em;
}
.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--primary);
  background: var(--primary-light);
}
.navbar-nav .nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 3px;
  background: var(--primary);
  border-radius: 2px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}
.header-phone {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--dark);
}
.header-phone .phone-icon {
  width: 42px;
  height: 42px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  animation: pulse-ring 2s infinite;
}
@keyframes pulse-ring {
  0% { box-shadow: 0 0 0 0 rgba(10, 127, 209, 0.4); }
  70% { box-shadow: 0 0 0 14px rgba(10, 127, 209, 0); }
  100% { box-shadow: 0 0 0 0 rgba(10, 127, 209, 0); }
}
.header-phone .phone-number {
  font-family: var(--font-primary);
  font-size: 1.15rem;
  color: var(--primary);
  font-weight: 900;
  letter-spacing: -0.02em;
}

/* ========== MOBILE MENU ========== */
@media (max-width: 991.98px) {
  .navbar-collapse {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-xl);
    margin-top: 12px;
    border: 1px solid var(--gray-200);
  }
  .header-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-top: 10px;
  }
  .header-phone {
    justify-content: center;
  }
  .header-actions .btn {
    text-align: center;
    justify-content: center;
  }
}

@media (max-width: 575.98px) {
  .header-top {
    display: none;
  }
  .header-brand-name {
    font-size: 1.15rem;
  }
  .header-logo {
    width: 42px;
    height: 42px;
  }
}

/* ========== FOOTER ========== */
.site-footer {
  background: var(--dark);
  color: rgba(255,255,255,0.7);
  font-weight: 400;
}
.footer-main {
  padding: 70px 0 40px;
}
.footer-widget h4,
.footer-widget h5 {
  font-family: var(--font-primary);
  color: var(--white);
  font-weight: 800;
  margin-bottom: 22px;
  position: relative;
  padding-bottom: 14px;
  letter-spacing: -0.02em;
}
.footer-widget h5::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 36px;
  height: 3px;
  background: var(--primary);
  border-radius: 2px;
}
.footer-widget p {
  font-size: 0.9rem;
  margin-bottom: 18px;
  color: rgba(255,255,255,0.65);
  line-height: 1.8;
}
.footer-widget ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-widget ul li {
  margin-bottom: 10px;
}
.footer-widget ul li a {
  font-family: var(--font-primary);
  color: rgba(255,255,255,0.65);
  transition: var(--transition-fast);
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 400;
}
.footer-widget ul li a:hover {
  color: var(--white);
  transform: translateX(5px);
}
.footer-widget ul li a i {
  font-size: 0.65rem;
  color: var(--primary);
}
.footer-contact-item {
  display: flex;
  gap: 12px;
  margin-bottom: 15px;
  font-size: 0.9rem;
  color: rgba(255,255,255,0.65);
}
.footer-contact-item i {
  color: var(--primary);
  margin-top: 4px;
  flex-shrink: 0;
  font-size: 0.9rem;
}
.footer-social {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}
.footer-social a {
  width: 40px;
  height: 40px;
  background: rgba(255,255,255,0.08);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  font-size: 0.95rem;
}
.footer-social a:hover {
  background: var(--primary);
  transform: translateY(-4px);
  color: var(--white);
  box-shadow: 0 6px 20px rgba(10,127,209,0.5);
}
.footer-map {
  border-radius: var(--radius-md);
  overflow: hidden;
  height: 200px;
  box-shadow: var(--shadow-lg);
}
.footer-map iframe {
  width: 100%;
  height: 100%;
  border: none;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 22px 0;
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
}
.footer-bottom a {
  color: var(--primary);
  font-weight: 600;
}
.footer-bottom a:hover {
  color: var(--white);
}