/* =============================================
   GLOBAL STYLES — SinoSource
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;500;600;700;800&family=Inter:wght@400;500;600;700&display=swap');

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  color: var(--color-text-primary);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  outline: none;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--fw-bold);
  line-height: 1.2;
  color: var(--color-text-primary);
}
h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }
p  { color: var(--color-text-secondary); line-height: 1.7; }

/* ---- Layout ---- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

section { padding: var(--space-24) 0; }

.section-tag {
  display: inline-block;
  font-size: var(--text-sm);
  font-weight: var(--fw-semi);
  font-family: var(--font-heading);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-4);
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: var(--fw-extra);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  line-height: 1.15;
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  line-height: 1.7;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-header .section-subtitle {
  margin: 0 auto;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.75rem 1.75rem;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--fw-semi);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  white-space: nowrap;
  line-height: 1;
}

.btn-accent {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 4px 14px rgba(0, 112, 243, 0.35);
}
.btn-accent:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0, 112, 243, 0.45);
}

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

.btn-ghost {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.5);
}
.btn-ghost:hover {
  background: rgba(255,255,255,0.1);
  border-color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}
.btn-outline:hover {
  background: var(--color-accent);
  color: #fff;
}

.btn-outline-dark {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}
.btn-outline-dark:hover {
  background: var(--color-primary);
  color: #fff;
}

.btn-lg { padding: 1rem 2.25rem; font-size: var(--text-lg); }
.btn-sm { padding: 0.5rem 1.25rem; font-size: var(--text-sm); }

/* ---- Navbar ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  z-index: var(--z-navbar);
  transition: background var(--transition-base), box-shadow var(--transition-base);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255,255,255,0.97);
  box-shadow: 0 1px 20px rgba(10,37,64,0.08);
  backdrop-filter: blur(12px);
}

.navbar.scrolled .navbar__logo,
.navbar.scrolled .navbar__menu a {
  color: var(--color-text-primary);
}

.navbar.scrolled .navbar__toggle {
  color: var(--color-text-primary);
}

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.navbar__logo {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--fw-extra);
  color: #fff;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  transition: color var(--transition-base);
}

.navbar__logo .logo-diamond {
  width: 28px;
  height: 28px;
  background: var(--color-accent);
  transform: rotate(45deg);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.navbar__logo .logo-diamond::after {
  content: 'S';
  color: #fff;
  font-size: 13px;
  font-weight: 800;
  transform: rotate(-45deg);
  display: block;
}

.navbar__menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.navbar__menu a {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--fw-semi);
  color: rgba(255,255,255,0.88);
  letter-spacing: 0.02em;
  transition: color var(--transition-fast);
  position: relative;
}

.navbar__menu a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-base);
}

.navbar__menu a:hover,
.navbar__menu a.active {
  color: #fff;
}

.navbar.scrolled .navbar__menu a {
  color: var(--color-text-secondary);
}

.navbar.scrolled .navbar__menu a:hover,
.navbar.scrolled .navbar__menu a.active {
  color: var(--color-accent);
}

.navbar__menu a:hover::after,
.navbar__menu a.active::after {
  width: 100%;
}

.navbar__cta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.navbar__toggle {
  display: none;
  color: #fff;
  font-size: var(--text-2xl);
  transition: color var(--transition-fast);
  z-index: 10;
}

/* Mobile Nav */
@media (max-width: 1023px) {
  .navbar__toggle { display: block; }
  .navbar__menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 300px;
    height: 100vh;
    background: var(--color-primary);
    flex-direction: column;
    align-items: flex-start;
    padding: 100px var(--space-8) var(--space-8);
    gap: var(--space-6);
    transition: right var(--transition-slow);
    box-shadow: -8px 0 30px rgba(0,0,0,0.2);
    z-index: 999;
  }
  .navbar__menu.open { right: 0; }
  .navbar__menu a {
    font-size: var(--text-lg);
    color: rgba(255,255,255,0.8);
    width: 100%;
    padding-bottom: var(--space-3);
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }
  .navbar__menu a::after { display: none; }
  .navbar__menu a:hover { color: #fff; }
  .navbar__cta .btn { display: none; }
  .nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 998;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
  }
  .nav-overlay.open {
    opacity: 1;
    pointer-events: all;
  }
}

/* ---- Page Hero (inner pages) ---- */
.page-hero {
  padding: calc(var(--navbar-height) + var(--space-16)) 0 var(--space-16);
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('https://images.unsplash.com/photo-1586528116311-ad8dd3c8310d?w=1920&q=80') center/cover no-repeat;
  opacity: 0.12;
}

.page-hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.page-hero__tag {
  display: inline-block;
  background: rgba(0, 112, 243, 0.2);
  color: rgba(255,255,255,0.9);
  border: 1px solid rgba(0, 112, 243, 0.4);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: var(--fw-semi);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-4);
}

.page-hero h1 {
  color: #fff;
  font-size: clamp(2rem, 4vw, 3.25rem);
  font-weight: var(--fw-extra);
  margin-bottom: var(--space-4);
}

.page-hero p {
  color: rgba(255,255,255,0.75);
  font-size: var(--text-lg);
  max-width: 600px;
  margin: 0 auto;
}

/* ---- Cards ---- */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

/* ---- Badges ---- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--fw-semi);
}

.badge-blue  { background: var(--color-accent-light); color: var(--color-accent); }
.badge-green { background: var(--color-success-light); color: var(--color-success); }
.badge-gold  { background: var(--color-gold-light); color: #8A6A1F; }

/* ---- Stars ---- */
.stars { color: #F59E0B; letter-spacing: 1px; font-size: var(--text-sm); }

/* ---- Form Elements ---- */
.form-group { margin-bottom: var(--space-5); }

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: var(--fw-semi);
  color: var(--color-text-primary);
  margin-bottom: var(--space-2);
}

.form-label span { color: var(--color-error); margin-left: 2px; }

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  color: var(--color-text-primary);
  background: var(--color-surface);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(0, 112, 243, 0.12);
}

.form-input.error,
.form-textarea.error { border-color: var(--color-error); }

.form-error {
  font-size: var(--text-xs);
  color: var(--color-error);
  margin-top: var(--space-1);
  display: none;
}

.form-error.show { display: block; }

.form-textarea { resize: vertical; min-height: 120px; }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

/* ---- Divider ---- */
.divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--space-8) 0;
}

/* ---- Tags / Chips ---- */
.chip {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-weight: var(--fw-medium);
}

/* ---- Section BG Variants ---- */
.bg-dark {
  background: var(--color-dark);
  color: #fff;
}

.bg-dark .section-title,
.bg-dark h2, .bg-dark h3 {
  color: #fff;
}

.bg-dark p {
  color: rgba(255,255,255,0.7);
}

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

/* ---- Footer ---- */
.footer {
  background: var(--color-dark);
  color: rgba(255,255,255,0.75);
  padding: var(--space-20) 0 var(--space-8);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--space-12);
  padding-bottom: var(--space-12);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer__brand .navbar__logo {
  color: #fff;
  margin-bottom: var(--space-4);
}

.footer__brand p {
  color: rgba(255,255,255,0.55);
  font-size: var(--text-sm);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.footer__social {
  display: flex;
  gap: var(--space-3);
}

.footer__social a {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.6);
  font-size: var(--text-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.footer__social a:hover {
  background: var(--color-accent);
  color: #fff;
}

.footer__col h4 {
  color: #fff;
  font-size: var(--text-sm);
  font-weight: var(--fw-semi);
  font-family: var(--font-heading);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: var(--space-5);
}

.footer__col ul li {
  margin-bottom: var(--space-3);
}

.footer__col ul li a {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.55);
  transition: color var(--transition-fast);
}

.footer__col ul li a:hover {
  color: rgba(255,255,255,0.9);
}

.footer__contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.55);
}

.footer__contact-item i {
  color: var(--color-accent);
  width: 16px;
  margin-top: 3px;
  flex-shrink: 0;
}

.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-6);
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.35);
}

.footer__bottom-links {
  display: flex;
  gap: var(--space-6);
}

.footer__bottom-links a {
  color: rgba(255,255,255,0.35);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer__bottom-links a:hover {
  color: rgba(255,255,255,0.7);
}

/* ---- Breadcrumb ---- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.55);
  margin-bottom: var(--space-4);
}

.breadcrumb a { color: rgba(255,255,255,0.55); transition: color var(--transition-fast); }
.breadcrumb a:hover { color: rgba(255,255,255,0.9); }
.breadcrumb span { color: rgba(255,255,255,0.85); }

/* ---- Responsive ---- */
@media (max-width: 1023px) {
  .footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
  .footer__brand { grid-column: 1 / -1; }
  section { padding: var(--space-16) 0; }
}

@media (max-width: 767px) {
  h1 { font-size: var(--text-4xl); }
  h2 { font-size: var(--text-3xl); }
  h3 { font-size: var(--text-2xl); }
  .container { padding: 0 var(--space-5); }
  .footer__grid { grid-template-columns: 1fr; gap: var(--space-8); }
  .footer__brand { grid-column: auto; }
  .footer__bottom { flex-direction: column; gap: var(--space-3); text-align: center; }
  .footer__bottom-links { justify-content: center; }
  .form-row { grid-template-columns: 1fr; }
  section { padding: var(--space-12) 0; }
}