/* ===== 全站色彩變數 (深色模式 - 預設) ===== */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #12182b;
  --accent-cyan: #00d4ff;
  --accent-purple: #a855f7;
  --accent-pink: #ec4899;
  --text-primary: rgba(255, 255, 255, 0.95);
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-muted: rgba(255, 255, 255, 0.5);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow-glow: 0 0 40px rgba(0, 212, 255, 0.15);
  --radius-lg: 16px;
  --radius-md: 12px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --navbar-bg: rgba(10, 14, 26, 0.8);
  --dropdown-bg: rgba(18, 24, 43, 0.95);
  --footer-bg: rgba(10, 14, 26, 0.9);
  --navbar-toggler-icon: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255, 255, 255, 0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ===== 淺色模式 ===== */
[data-theme="light"] {
  --bg-primary: #f0f4f8;
  --bg-secondary: #e2e8f0;
  --accent-cyan: #0891b2;
  --accent-purple: #7c3aed;
  --accent-pink: #db2777;
  --text-primary: rgba(15, 23, 42, 0.95);
  --text-secondary: rgba(51, 65, 85, 0.85);
  --text-muted: rgba(100, 116, 139, 0.8);
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(148, 163, 184, 0.3);
  --shadow-glow: 0 0 40px rgba(8, 145, 178, 0.12);
  --navbar-bg: rgba(255, 255, 255, 0.85);
  --dropdown-bg: rgba(255, 255, 255, 0.98);
  --footer-bg: rgba(248, 250, 252, 0.95);
  --navbar-toggler-icon: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(15, 23, 42, 0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ===== 基礎設定 ===== */
html {
  font-size: 14px;
  position: relative;
  min-height: 100%;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

body {
  font-family: 'Inter', 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background:
    radial-gradient(ellipse 80% 50% at 20% 0%, rgba(0, 212, 255, 0.15), transparent),
    radial-gradient(ellipse 60% 40% at 80% 10%, rgba(168, 85, 247, 0.12), transparent),
    radial-gradient(ellipse 50% 30% at 50% 100%, rgba(236, 72, 153, 0.08), transparent),
    linear-gradient(180deg, var(--bg-primary), var(--bg-secondary));
  background-attachment: fixed;
  color: var(--text-primary);
  margin: 0;
  min-height: 100vh;
}

/* ===== 導覽列 ===== */
.navbar {
  background: var(--navbar-bg) !important;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--glass-border) !important;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
  padding: 0.8rem 0;
  transition: var(--transition);
}

.navbar-brand {
  font-weight: 700;
  font-size: 1.4rem;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: var(--transition);
}

.navbar-brand:hover {
  filter: brightness(1.2);
  transform: scale(1.02);
}

.nav-link {
  color: var(--text-secondary) !important;
  font-weight: 500;
  padding: 0.5rem 1rem !important;
  border-radius: var(--radius-md);
  transition: var(--transition);
  position: relative;
}

.nav-link:hover {
  color: var(--text-primary) !important;
  background: var(--glass-bg);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  transition: var(--transition);
  transform: translateX(-50%);
}

.nav-link:hover::after {
  width: 80%;
}

/* ===== 下拉選單 ===== */
.dropdown-menu {
  background: var(--dropdown-bg) !important;
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border) !important;
  border-radius: var(--radius-lg) !important;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), var(--shadow-glow);
  padding: 0.5rem !important;
  margin-top: 0.5rem !important;
  animation: dropdownFadeIn 0.25s ease;
}

@keyframes dropdownFadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.dropdown-item {
  color: var(--text-secondary) !important;
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem !important;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.dropdown-item:hover,
.dropdown-item:focus {
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.15), rgba(168, 85, 247, 0.15)) !important;
  color: var(--text-primary) !important;
  transform: translateX(4px);
}

.dropdown-item i {
  font-size: 1.1rem;
  width: 24px;
  text-align: center;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.dropdown-toggle::after {
  border: none !important;
  content: '▾';
  font-size: 0.7rem;
  margin-left: 0.5rem;
  transition: var(--transition);
}

.dropdown-toggle.show::after {
  transform: rotate(180deg);
}

/* ===== 漢堡選單按鈕 ===== */
.navbar-toggler {
  border: 1px solid var(--glass-border) !important;
  background: var(--glass-bg);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
}

.navbar-toggler-icon {
  background-image: var(--navbar-toggler-icon) !important;
}

/* ===== 主要內容區 ===== */
.container {
  max-width: 1200px;
}

main {
  padding: 2rem 0;
}

/* ===== 首頁歡迎區 ===== */
.hero-section {
  text-align: center;
  padding: 4rem 1rem;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s ease infinite;
  background-size: 200% 200%;
}

@keyframes gradientShift {

  0%,
  100% {
    background-position: 0% 50%;
  }

  50% {
    background-position: 100% 50%;
  }
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 3rem;
  line-height: 1.6;
}

/* ===== 工具卡片 ===== */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  padding: 1rem 0;
}

.tool-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-decoration: none;
  color: var(--text-primary);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  transform: scaleX(0);
  transition: var(--transition);
}

.tool-card:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 212, 255, 0.3);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), var(--shadow-glow);
  color: var(--text-primary);
  text-decoration: none;
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.2), rgba(168, 85, 247, 0.2));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 1.25rem;
}

.tool-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.tool-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
}

.tool-arrow {
  position: absolute;
  right: 1.5rem;
  bottom: 1.5rem;
  font-size: 1.25rem;
  color: var(--text-muted);
  transition: var(--transition);
}

.tool-card:hover .tool-arrow {
  color: var(--accent-cyan);
  transform: translateX(5px);
}

/* ===== Footer ===== */
.footer {
  background: var(--footer-bg);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--glass-border);
  color: var(--text-muted);
  padding: 1.5rem 0;
  position: absolute;
  bottom: 0;
  width: 100%;
}

.footer a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: var(--transition);
}

.footer a:hover {
  color: var(--accent-purple);
}

/* ===== 表單元素 ===== */
.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  border: none;
  border-radius: var(--radius-md);
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  transition: var(--transition);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 212, 255, 0.3);
}

.form-control {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  padding: 0.75rem 1rem;
}

.form-control:focus {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
  color: var(--text-primary);
}

/* ===== 響應式調整 ===== */
@media (max-width: 767px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

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

  .navbar-collapse {
    background: var(--dropdown-bg);
    border-radius: var(--radius-lg);
    margin-top: 1rem;
    padding: 1rem;
    border: 1px solid var(--glass-border);
  }
}

/* ===== 主題切換按鈕 ===== */
.theme-toggle-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.theme-toggle-btn:hover {
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.15), rgba(168, 85, 247, 0.15));
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: scale(1.05);
}

.theme-toggle-btn:active {
  transform: scale(0.95);
}

.theme-toggle-btn i {
  font-size: 1.1rem;
  transition: transform 0.3s ease;
}

.theme-toggle-btn:hover i {
  transform: rotate(15deg);
}

/* 淺色模式下的背景調整 */
[data-theme="light"] body {
  background:
    radial-gradient(ellipse 80% 50% at 20% 0%, rgba(8, 145, 178, 0.1), transparent),
    radial-gradient(ellipse 60% 40% at 80% 10%, rgba(124, 58, 237, 0.08), transparent),
    radial-gradient(ellipse 50% 30% at 50% 100%, rgba(219, 39, 119, 0.06), transparent),
    linear-gradient(180deg, var(--bg-primary), var(--bg-secondary));
  background-attachment: fixed;
}