/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --gold: #C5A55A;
  --gold-light: #D4B96A;
  --gold-dark: #8B6914;
  --navy: #1B365D;
  --navy-light: #2A4A7A;
  --green: #2E7D5B;
  --white: #FFFFFF;
  --off-white: #F8F6F0;
  --gray-light: #F0EDE6;
  --gray: #888;
  --text: #2C2C2C;
  --text-light: #555;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --shadow-hover: 0 6px 24px rgba(0,0,0,0.12);
  --radius: 12px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 70px;
}

body {
  font-family: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", -apple-system, sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}

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

ul {
  list-style: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
}

.section-title {
  text-align: center;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  font-size: 1.1rem;
  color: var(--text-light);
  margin-bottom: 60px;
}

.btn {
  display: inline-block;
  padding: 14px 36px;
  border-radius: 50px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.btn-primary {
  background: var(--gold);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--gold-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 8px rgba(0,0,0,0.06);
  transition: background var(--transition);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.nav-brand {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--navy);
  letter-spacing: 2px;
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  transition: color var(--transition);
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gold);
  transition: width var(--transition);
}

.nav-links a:hover {
  color: var(--gold);
}

.nav-links a:hover::after {
  width: 100%;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 26px;
  height: 2px;
  background: var(--navy);
  transition: all var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(135deg, var(--navy) 0%, #0D1F3C 50%, #1A3A5C 100%);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(197, 165, 90, 0.15) 0%, transparent 50%),
              radial-gradient(circle at 70% 30%, rgba(197, 165, 90, 0.1) 0%, transparent 40%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% { transform: translate(0, 0); }
  100% { transform: translate(-5%, 3%); }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(197,165,90,0.05)" stroke-width="0.5"/></svg>') repeat;
  background-size: 200px;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 0 24px;
}

.hero-title {
  font-size: 4.5rem;
  font-weight: 900;
  color: var(--gold);
  letter-spacing: 12px;
  margin-bottom: 16px;
  text-shadow: 0 2px 20px rgba(197, 165, 90, 0.3);
}

.hero-subtitle {
  font-size: 1.6rem;
  color: rgba(255, 255, 255, 0.9);
  font-weight: 300;
  letter-spacing: 4px;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.65);
  line-height: 1.8;
  margin-bottom: 40px;
}

.hero-cta {
  font-size: 1.1rem;
  padding: 16px 48px;
}

/* ===== Concept Section ===== */
.concept-section {
  background: var(--off-white);
}

.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.concept-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px 32px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.concept-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.concept-card h3 {
  font-size: 1.15rem;
  color: var(--navy);
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--gold);
}

.concept-list li {
  margin-bottom: 16px;
}

.concept-list strong {
  display: block;
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 4px;
}

.concept-list p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* ===== Goals Section ===== */
.goals-section {
  background: var(--white);
}

.goals-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.goal-card {
  background: var(--off-white);
  border-radius: var(--radius);
  padding: 28px 24px;
  position: relative;
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.goal-number {
  position: absolute;
  top: 12px;
  right: 16px;
  font-size: 2rem;
  font-weight: 900;
  color: rgba(27, 54, 93, 0.08);
}

.goal-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.goal-card h4 {
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 10px;
}

.goal-card p {
  font-size: 0.85rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* ===== Fund Section ===== */
.fund-section {
  background: var(--navy);
  color: var(--white);
}

.fund-section .section-title {
  color: var(--gold);
}

.fund-section .section-subtitle {
  color: rgba(255, 255, 255, 0.7);
}

.fund-chart {
  max-width: 700px;
  margin: 0 auto;
}

.fund-item {
  margin-bottom: 32px;
}

.fund-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.fund-name {
  font-weight: 600;
  font-size: 1rem;
}

.fund-percent {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--gold);
}

.fund-bar {
  height: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 6px;
  overflow: hidden;
}

.fund-fill {
  height: 100%;
  width: 0;
  background: var(--bar-color);
  border-radius: 6px;
  transition: width 1.2s ease-out;
}

.fund-desc {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.5);
  margin-top: 6px;
}

/* ===== Volunteer Section ===== */
.volunteer-section {
  background: var(--off-white);
}

.volunteer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 48px;
}

.volunteer-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 28px;
  box-shadow: var(--shadow);
}

.volunteer-card h4 {
  font-size: 1.15rem;
  color: var(--navy);
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--gold);
}

.volunteer-card ul {
  list-style: none;
}

.volunteer-card li {
  font-size: 0.92rem;
  color: var(--text-light);
  padding: 8px 0;
  padding-left: 20px;
  position: relative;
}

.volunteer-card li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--gold);
  font-weight: 700;
}

.volunteer-cta {
  text-align: center;
}

/* ===== Registration Section ===== */
.registration-section {
  background: var(--white);
}

.steps-timeline {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
}

.step {
  text-align: center;
  flex: 1;
  max-width: 180px;
  position: relative;
}

.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--gold);
  font-size: 1.2rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
}

.step-icon {
  font-size: 2rem;
  margin-bottom: 10px;
}

.step h4 {
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 8px;
}

.step p {
  font-size: 0.85rem;
  color: var(--text-light);
  line-height: 1.4;
}

.step-connector {
  flex: 0 0 40px;
  height: 2px;
  background: var(--gold);
  margin-top: 24px;
  position: relative;
}

.step-connector::after {
  content: "";
  position: absolute;
  right: -4px;
  top: -3px;
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--gold);
  border-top: 2px solid var(--gold);
  transform: rotate(45deg);
}

/* ===== Footer ===== */
.footer {
  background: #0D1F3C;
  color: rgba(255, 255, 255, 0.8);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-info h3 {
  font-size: 1.3rem;
  color: var(--gold);
  margin-bottom: 12px;
}

.footer-info p {
  color: rgba(255, 255, 255, 0.5);
}

.footer-contact h4,
.footer-social h4 {
  font-size: 1rem;
  color: var(--white);
  margin-bottom: 16px;
}

.footer-contact p {
  font-size: 0.9rem;
  margin-bottom: 8px;
  color: rgba(255, 255, 255, 0.6);
}

.social-links {
  display: flex;
  gap: 12px;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 12px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--gold);
  font-size: 0.75rem;
  font-weight: 700;
  transition: all var(--transition);
}

.social-links a:hover {
  background: var(--gold);
  color: var(--navy);
}

.footer-bottom {
  text-align: center;
  padding: 24px 0;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.35);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .goals-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px 24px;
    gap: 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links li {
    padding: 12px 0;
    border-bottom: 1px solid var(--gray-light);
  }

  .nav-links a::after {
    display: none;
  }

  .hero-title {
    font-size: 2.8rem;
    letter-spacing: 6px;
  }

  .hero-subtitle {
    font-size: 1.1rem;
    letter-spacing: 2px;
  }

  .hero-desc {
    font-size: 0.9rem;
  }

  .hero-desc br {
    display: none;
  }

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 1.7rem;
  }

  .section-subtitle {
    font-size: 0.95rem;
    margin-bottom: 40px;
  }

  .concept-grid {
    grid-template-columns: 1fr;
  }

  .goals-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .volunteer-grid {
    grid-template-columns: 1fr;
  }

  .steps-timeline {
    flex-direction: column;
    align-items: center;
    gap: 0;
  }

  .step {
    max-width: 280px;
    margin-bottom: 8px;
  }

  .step-connector {
    width: 2px;
    height: 30px;
    flex: 0 0 30px;
    margin-top: 0;
  }

  .step-connector::after {
    right: -3px;
    top: auto;
    bottom: -4px;
    transform: rotate(135deg);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2.2rem;
  }

  .goals-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gold);
  color: var(--white);
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--gold-dark);
  transform: translateY(-3px);
}

/* ===== Scroll Animation ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}