/* ========================================================
   MDA SERVICE CORP. - Official Website Stylesheet
   Aesthetic: White background, Chinese-style river & tree line art,
   Navy Blue (#0A2540) & Warm Gold (#C6923B) brand identity.
   ======================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-serif: Georgia, "Times New Roman", "Songti SC", SimSun, "Noto Serif CJK SC", serif;
  --font-chinese: "Songti SC", STSong, SimSun, "Noto Serif CJK SC", Georgia, serif;
  --color-primary: #0A2540;        /* Deep Navy from business card */
  --color-primary-light: #16385C;
  --color-gold: #C6923B;           /* Warm Golden Bridge Arch */
  --color-gold-light: #E5BE76;
  --color-gold-dark: #A57324;
  --color-seal-red: #B91C1C;       /* Traditional Chinese Seal Red */
  --color-ink-charcoal: #1E293B;
  --color-bg-white: #FFFFFF;
  --color-bg-soft: #F9FAF9;
  --color-line-soft: rgba(10, 37, 64, 0.08);
}

body {
  font-family: var(--font-sans);
  color: var(--color-ink-charcoal);
  background-color: var(--color-bg-white);
  overflow-x: hidden;
  scroll-behavior: smooth;
}

/* Full-length Shan Shui Watermark Background Layer */
.shanshui-bg-layer {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url('../images/shanshui_clean.png');
  background-repeat: repeat-y;
  background-position: center top;
  background-size: 800px auto;
  opacity: 0.07;
  pointer-events: none;
  z-index: 0;
  mix-blend-mode: multiply;
}

@media (max-width: 768px) {
  .shanshui-bg-layer {
    background-size: 100vw auto;
    opacity: 0.06;
  }
}

.font-serif-cormorant {
  font-family: var(--font-serif);
}

.font-chinese {
  font-family: var(--font-chinese);
}

/* Chinese Seal Stamp Style */
.chinese-seal {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--color-seal-red);
  color: var(--color-seal-red);
  padding: 4px 8px;
  border-radius: 4px;
  font-family: var(--font-chinese);
  font-weight: 700;
  letter-spacing: 2px;
  background-color: rgba(185, 28, 28, 0.04);
  box-shadow: inset 0 0 0 1px rgba(185, 28, 28, 0.15);
  position: relative;
}

.chinese-seal::before {
  content: "";
  position: absolute;
  top: 1px;
  left: 1px;
  right: 1px;
  bottom: 1px;
  border: 1px dashed rgba(185, 28, 28, 0.35);
  pointer-events: none;
}

/* Golden Gradient Text & Borders */
.gold-text-gradient {
  background: linear-gradient(135deg, #B8860B 0%, #D4AF37 50%, #C6923B 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gold-border-gradient {
  border-image: linear-gradient(135deg, #B8860B, #E5BE76, #A57324) 1;
}

/* Chinese River Line Animations */
.river-line-path {
  fill: none;
  stroke: rgba(10, 37, 64, 0.08);
  stroke-width: 1.5;
  stroke-linecap: round;
  transition: stroke 0.4s ease;
}

.river-line-gold {
  fill: none;
  stroke: rgba(198, 146, 59, 0.22);
  stroke-width: 1.2;
  stroke-linecap: round;
}

/* Subtle Wave Drift */
@keyframes waveDrift {
  0% { transform: translateX(0) translateY(0); }
  50% { transform: translateX(-15px) translateY(3px); }
  100% { transform: translateX(0) translateY(0); }
}

.animate-wave-drift {
  animation: waveDrift 14s ease-in-out infinite;
}

@keyframes waveDriftReverse {
  0% { transform: translateX(0) translateY(0); }
  50% { transform: translateX(15px) translateY(-3px); }
  100% { transform: translateX(0) translateY(0); }
}

.animate-wave-reverse {
  animation: waveDriftReverse 18s ease-in-out infinite;
}

/* Elegant Image Frame with Oriental Ring */
.founder-portrait-frame {
  position: relative;
  border-radius: 24px;
  overflow: hidden;
  box-shadow: 0 20px 45px -10px rgba(10, 37, 64, 0.12);
  border: 4px solid #FFFFFF;
}

.founder-portrait-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 20px;
  border: 1px solid rgba(198, 146, 59, 0.3);
  pointer-events: none;
}

/* Business Card 3D Flip */
.flip-card-container {
  perspective: 1000px;
}

.flip-card-inner {
  position: relative;
  width: 100%;
  transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.flip-card-container:hover .flip-card-inner,
.flip-card-inner.is-flipped {
  transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 15px 35px -5px rgba(10, 37, 64, 0.15);
}

.flip-card-back {
  transform: rotateY(180deg);
}

/* Interactive Service Card Hover */
.service-card {
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  border: 1px solid rgba(10, 37, 64, 0.07);
  background: #FFFFFF;
}

.service-card:hover {
  transform: translateY(-6px);
  border-color: rgba(198, 146, 59, 0.4);
  box-shadow: 0 20px 35px -10px rgba(10, 37, 64, 0.08);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: #F8F9FA;
}

::-webkit-scrollbar-thumb {
  background: #CBD5E1;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #94A3B8;
}

/* Modal Overlay */
.modal-overlay {
  background-color: rgba(10, 37, 64, 0.6);
  backdrop-filter: blur(4px);
}