/* ========================================
   Global Styles — Portfolio of Yu Yuanhao
   ======================================== */

:root {
  --color-bg: #FFFFFF;
  --color-bg-soft: #F4F7FB;
  --color-bg-blue: #EDF3FF;
  --color-primary: #0A4DA6;
  --color-primary-light: #1E6FEB;
  --color-primary-deep: #052855;
  --color-text: #0F172A;
  --color-text-secondary: #64748B;
  --color-text-muted: #94A3B8;
  --color-border: #E2E8F0;
  --color-border-light: #F1F5F9;
  --max-width: 1700px;
  --font-zh: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-en: 'Space Grotesk', 'Helvetica Neue', Arial, sans-serif;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-zh);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  overflow-x: hidden;
}

#root {
  width: 100%;
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-zh);
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text);
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* Utility Classes */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 48px;
}

@media (max-width: 1024px) {
  .container {
    padding: 0 24px;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-60px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(60px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(30, 111, 235, 0.3); }
  50% { box-shadow: 0 0 20px 4px rgba(30, 111, 235, 0.15); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.animate-fade-in-up {
  animation: fadeInUp 0.8s var(--transition-slow) forwards;
}

.animate-fade-in {
  animation: fadeIn 0.6s ease forwards;
}

.animate-slide-in-left {
  animation: slideInLeft 0.8s var(--transition-slow) forwards;
}

.animate-slide-in-right {
  animation: slideInRight 0.8s var(--transition-slow) forwards;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-soft);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* Selection */
::selection {
  background: rgba(10, 77, 166, 0.15);
  color: var(--color-primary-deep);
}

/* ========================================
   Responsive Styles
   ======================================== */

@media (max-width: 1200px) {
  .about-grid {
    grid-template-columns: 1fr !important;
    gap: 60px !important;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }
}

@media (max-width: 1024px) {
  .projects-grid {
    grid-template-columns: 1fr !important;
  }

  .strengths-grid {
    grid-template-columns: 1fr !important;
  }

  .capabilities-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }

  .more-projects-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }

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

  .mobile-menu-btn {
    display: flex !important;
  }
}

@media (max-width: 768px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }

  .capabilities-grid {
    grid-template-columns: 1fr 1fr !important;
  }

  .more-projects-grid {
    grid-template-columns: 1fr !important;
  }

  .contact-footer {
    flex-direction: column !important;
    text-align: center !important;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr 1fr !important;
    gap: 12px !important;
  }

  .stats-grid > div {
    padding: 16px 12px !important;
  }

  .capabilities-grid {
    grid-template-columns: 1fr !important;
  }
}

/* AppHub responsive */
@media (max-width: 768px) {
  .apphub-sidebar {
    width: 200px !important;
    padding: 16px 12px !important;
  }

  .insights-grid {
    grid-template-columns: 1fr !important;
  }

  .review-form-grid {
    grid-template-columns: 1fr !important;
  }

  .apphub-pad {
    padding-left: 16px !important;
    padding-right: 16px !important;
  }
}

@media (max-width: 640px) {
  .apphub-sidebar {
    display: none !important;
  }

  .apphub-mobile-nav {
    display: flex !important;
  }

  .insights-grid {
    padding: 16px 12px !important;
  }
}

/* Slide-in animation for history drawer */
@keyframes slideInRight {
  from {
    transform: translateX(100%);
  }
  to {
    transform: translateX(0);
  }
}

/* Bounce animation for typing */
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.08); opacity: 0.85; }
}

/* Nav hover underline effect */
a:hover .nav-underline {
  width: 100% !important;
}

/* Floating bot */
.bot-img {
  animation: float 3s ease-in-out infinite;
}

/* Video demo modules in project cards */
.video-modules-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

@media (max-width: 900px) {
  .video-modules-grid {
    grid-template-columns: 1fr;
  }
}

.bot-img.bot-wave {
  animation: botWave 1.3s ease-in-out 2 !important;
  transform-origin: 50% 88%;
}

@keyframes botWave {
  0%, 100% { transform: rotate(0deg); }
  15% { transform: rotate(-10deg); }
  30% { transform: rotate(9deg); }
  45% { transform: rotate(-7deg); }
  60% { transform: rotate(6deg); }
  75% { transform: rotate(-4deg); }
  90% { transform: rotate(2deg); }
}

@keyframes botGlow {
  0%, 100% { transform: scale(1); opacity: 0.85; }
  50% { transform: scale(1.14); opacity: 0.2; }
}

@media (max-width: 768px) {
  .floating-bot {
    bottom: 20px !important;
    right: 16px !important;
  }
  .floating-bot button {
    width: 72px !important;
    height: 72px !important;
  }
}

/* ========================================
   Mobile Responsive Overrides
   ======================================== */

@media (max-width: 768px) {
  /* --- Hero --- */
  #hero {
    height: auto !important;
    min-height: 100vh !important;
    padding: 100px 0 80px !important;
  }
  #hero h1 {
    font-size: clamp(36px, 11vw, 52px) !important;
    letter-spacing: 2px !important;
    line-height: 1.1 !important;
  }
  #hero .hero-subtitle {
    font-size: 11px !important;
    letter-spacing: 4px !important;
    margin-top: 8px !important;
  }
  #hero .hero-desc {
    font-size: 14px !important;
    line-height: 1.7 !important;
    margin-bottom: 32px !important;
    padding: 0 4px !important;
  }
  #hero .hero-btn {
    padding: 12px 24px !important;
    font-size: 14px !important;
  }

  /* --- Sections global --- */
  #about,
  #projects,
  #strengths {
    padding: 80px 0 !important;
  }
  #contact {
    min-height: auto !important;
    padding: 80px 0 !important;
  }
  #contact .contact-container {
    padding: 0 !important;
  }

  /* --- Section headers --- */
  #about h2,
  #projects h2,
  #strengths h2,
  #contact h2 {
    font-size: clamp(26px, 7vw, 36px) !important;
  }

  /* --- About --- */
  .about-grid {
    gap: 40px !important;
  }
  .about-grid > div:first-child > div:first-child {
    max-width: 320px !important;
    margin: 0 auto 24px !important;
  }

  /* --- Stats --- */
  .stats-grid > div {
    padding: 16px 8px !important;
  }
  .stats-grid .stat-value {
    font-size: 20px !important;
  }

  /* --- Projects --- */
  .projects-grid {
    gap: 24px !important;
  }
  .project-image {
    height: 200px !important;
  }
  .more-project-image {
    height: 160px !important;
  }

  /* --- Strengths --- */
  .strengths-grid {
    gap: 20px !important;
    margin-bottom: 60px !important;
  }
  .strength-card {
    padding: 28px 20px !important;
  }
  .strength-card .strength-accent {
    left: 20px !important;
    right: 20px !important;
  }
  .capabilities-grid {
    gap: 12px !important;
  }
  .capabilities-grid > div {
    padding: 20px 12px !important;
  }

  /* --- Contact --- */
  .contact-card {
    min-width: unset !important;
    width: 100% !important;
    max-width: 340px !important;
    padding: 20px 24px !important;
  }
  .contact-footer {
    margin-top: 60px !important;
  }

  /* --- AppHub --- */
  .apphub-sidebar {
    display: none !important;
  }
  .apphub-mobile-nav {
    display: flex !important;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 14px !important;
  }

  #hero {
    padding: 90px 0 60px !important;
  }
  #hero h1 {
    font-size: 34px !important;
  }

  .project-image {
    height: 180px !important;
  }
  .more-project-image {
    height: 140px !important;
  }

  .strength-card {
    padding: 24px 16px !important;
  }
  .strength-card .strength-accent {
    left: 16px !important;
    right: 16px !important;
  }

  .stats-grid {
    gap: 8px !important;
  }
  .stats-grid > div {
    padding: 14px 6px !important;
    border-radius: 10px !important;
  }

  .contact-card {
    padding: 18px 20px !important;
  }
}