/* ============================================================
   空中英語教室教育集團 — 共用樣式表
   Studio Classroom Group — Global Stylesheet
   依據 DESIGN_SPEC.md 規範實作
   ============================================================ */

/* ── 1. CSS Custom Properties（設計變數） ── */
:root {
  /* 品牌主色 */
  --color-brand-dark:   #1A3A5C;
  --color-brand-mid:    #2A5F8F;
  --color-brand-light:  #E8F2FB;

  /* 三刊識別色 */
  --color-lt:           #ffcb05;  /* 大家說英語 LT — 鮮黃 */
  --color-lt-bg:        #FFFBE6;
  --color-sc:           #00b1cd;  /* 空中英語教室 SC — 天藍 */
  --color-sc-bg:        #E0F8FC;
  --color-ad:           #ed1c24;  /* 彭蒙惠英語 AD — 正紅 */
  --color-ad-bg:        #FDEAEA;
  --color-tr:           #10B981;  /* 好想講英語 TR — 翠綠 */
  --color-tr-bg:        #ECFDF5;

  /* 中性色 */
  --color-text-primary:   #1A1A1A;
  --color-text-secondary: #555555;
  --color-text-muted:     #999999;
  --color-border:         #E0E0E0;
  --color-bg-white:       #FFFFFF;
  --color-bg-light:       #F5F7FA;

  /* 功能色 */
  --color-success: #27AE60;
  --color-warning: #F39C12;
  --color-error:   #E74C3C;
  --color-info:    #2A5F8F;

  /* 間距（8px 基準） */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-xxl: 80px;

  /* 圓角 */
  --radius-sm:   4px;
  --radius-md:   8px;
  --radius-lg:   12px;
  --radius-pill: 20px;

  /* 陰影 */
  --shadow-1: 0 1px 4px rgba(0,0,0,0.08);
  --shadow-2: 0 4px 12px rgba(0,0,0,0.12);
  --shadow-3: 0 8px 24px rgba(0,0,0,0.16);
  --shadow-4: 0 16px 40px rgba(0,0,0,0.20);

  /* 導覽列高度 */
  --nav-height: 64px;

  /* 過渡 */
  --transition: all 0.3s ease;

  /* 最大寬度 */
  --max-width: 1280px;
}

/* ── 2. Reset & Base ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: 'Noto Sans TC', 'Inter', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg-white);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-brand-mid);
  text-decoration: none;
  transition: var(--transition);
}

a:hover { color: var(--color-brand-dark); }

ul, ol { list-style: none; }

/* ── 3. 版面容器 ── */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

@media (min-width: 768px) {
  .container { padding: 0 var(--space-xl); }
}

/* ── 4. 導覽列（Sticky Nav） ── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-brand-dark);
  z-index: 1000;
  transition: box-shadow 0.3s ease;
}

.navbar.scrolled {
  box-shadow: var(--shadow-4);
}

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

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.nav-logo img {
  height: 36px;
  width: auto;
}

.nav-logo span { color: #fff; }

/* 桌面選單 */
.nav-menu {
  display: none;
  align-items: center;
  gap: var(--space-sm);
}

.nav-menu a {
  color: rgba(255,255,255,0.85);
  font-size: 15px;
  font-weight: 500;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
  color: #fff;
  background: rgba(255,255,255,0.15);
}

/* 導覽列右側 */
.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* 漢堡選單（行動端） */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--space-sm);
  background: none;
  border: none;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--transition);
}

.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 行動端側滑選單 */
.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 280px;
  height: 100vh;
  background: var(--color-brand-dark);
  z-index: 999;
  padding: calc(var(--nav-height) + var(--space-xl)) var(--space-xl) var(--space-xl);
  transition: right 0.35s ease-in-out;
  overflow-y: auto;
}

.mobile-menu.open { right: 0; }

.mobile-menu a {
  display: block;
  color: rgba(255,255,255,0.85);
  font-size: 16px;
  font-weight: 500;
  padding: var(--space-md) 0;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition);
}

.mobile-menu a:hover { color: #fff; padding-left: var(--space-sm); }

/* 遮罩 */
.overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 998;
}

.overlay.open { display: block; }

/* 桌面顯示選單 */
@media (min-width: 768px) {
  .nav-menu { display: flex; }
  .nav-toggle { display: none; }
}

/* ── 5. 頁面主體（補償 Sticky Nav 高度） ── */
.page-content {
  padding-top: var(--nav-height);
}

/* ── 6. 按鈕系統 ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  height: 44px;
  padding: 0 var(--space-lg);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.btn:active { transform: scale(0.98); }

/* 主要按鈕 */
.btn-primary {
  background: var(--color-brand-dark);
  color: #fff;
  border-color: var(--color-brand-dark);
}
.btn-primary:hover {
  background: var(--color-brand-mid);
  border-color: var(--color-brand-mid);
  color: #fff;
}

/* 次要按鈕 */
.btn-secondary {
  background: transparent;
  color: var(--color-brand-dark);
  border-color: var(--color-brand-dark);
}
.btn-secondary:hover {
  background: var(--color-brand-light);
  color: var(--color-brand-dark);
}

/* 白色按鈕（用於深色背景） */
.btn-white {
  background: #fff;
  color: var(--color-brand-dark);
  border-color: #fff;
}
.btn-white:hover {
  background: rgba(255,255,255,0.9);
  color: var(--color-brand-dark);
}

/* 輪廓白色按鈕 */
.btn-outline-white {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.6);
}
.btn-outline-white:hover {
  background: rgba(255,255,255,0.15);
  border-color: #fff;
  color: #fff;
}

/* 按鈕尺寸 */
.btn-lg { height: 52px; padding: 0 var(--space-xl); font-size: 16px; }
.btn-sm { height: 36px; padding: 0 var(--space-md); font-size: 13px; }

/* 行動端最小點擊尺寸 */
@media (max-width: 767px) {
  .btn { min-height: 48px; }
}

/* ── 7. 區塊標題 ── */
.section-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-label {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-brand-mid);
  margin-bottom: var(--space-sm);
}

.section-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-text-primary);
  line-height: 1.3;
  font-family: Georgia, serif;
}

.section-subtitle {
  margin-top: var(--space-md);
  font-size: 16px;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

@media (max-width: 767px) {
  .section-title { font-size: 24px; }
}

/* ── 8. 卡片 ── */
.card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
  overflow: hidden;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-2);
  transform: translateY(-4px);
}

/* ── 9. Badge / 標籤 ── */
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.badge-lt { background: var(--color-lt); color: #1A1A1A; }
.badge-sc { background: var(--color-sc); color: #fff; }
.badge-ad { background: var(--color-ad); color: #fff; }
.badge-tr { background: var(--color-tr); color: #fff; }

/* ── 10. 頁尾（Footer） ── */
.footer {
  background: #1A1A1A;
  color: rgba(255,255,255,0.75);
  padding: var(--space-xxl) 0 var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
  .footer-grid { grid-template-columns: 2fr 3fr; }
}

.footer-brand .brand-name {
  font-size: 20px;
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-md);
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.7;
  max-width: 300px;
}

.footer h4 {
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
}

.footer ul li {
  margin-bottom: var(--space-sm);
}

.footer ul li a {
  font-size: 14px;
  color: rgba(255,255,255,0.65);
  transition: var(--transition);
}

.footer ul li a:hover { color: #fff; }

.footer-social {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-md);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.75);
  font-size: 16px;
  transition: var(--transition);
}

.footer-social a:hover {
  background: var(--color-brand-mid);
  color: #fff;
}

.footer .footer-links-area {
  display: flex;
  flex-wrap: wrap;
  align-content: flex-start;
  gap: 8px;
  min-width: 0;
}

.footer .footer-link-item {
  display: inline-block;
  background: transparent;
  border-radius: 6px;
  padding: 8px 16px;
  color: rgba(255,255,255,0.8);
  font-size: 14px;
  line-height: 1.4;
  text-decoration: none;
  transition: background 0.2s, color 0.2s;
}

.footer .footer-link-item:hover {
  background: rgba(255,255,255,0.15);
  color: #fff;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: var(--space-lg);
  font-size: 13px;
  color: rgba(255,255,255,0.4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* ── 11. 進場動畫 ── */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ── 12. 表單元素 ── */
.form-group {
  margin-bottom: var(--space-md);
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.form-control {
  display: block;
  width: 100%;
  height: 44px;
  padding: 0 var(--space-md);
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text-primary);
  background: var(--color-bg-white);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  outline: none;
}

.form-control:focus {
  border-color: var(--color-brand-mid);
  box-shadow: 0 0 0 3px rgba(42,95,143,0.2);
}

.form-control.error {
  border-color: var(--color-error);
}

.form-control.success {
  border-color: var(--color-success);
}

.form-error {
  font-size: 13px;
  color: var(--color-error);
  margin-top: var(--space-xs);
}

@media (max-width: 767px) {
  .form-control { height: 48px; font-size: 16px; }
}

/* ── 13. 頁面標題區（內頁用） ── */
.page-hero {
  background: linear-gradient(135deg, #0f0c29 0%, #1a3a5c 40%, #24243e 100%);
  color: #fff;
  padding: var(--space-xxl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 15% 50%, rgba(245,197,24,.18) 0%, transparent 55%),
    radial-gradient(circle at 85% 30%, rgba(232,82,74,.15) 0%, transparent 55%);
  pointer-events: none;
}

.page-hero .container {
  position: relative;
  z-index: 1;
}

.page-hero h1 {
  font-size: 36px;
  font-weight: 700;
  font-family: Georgia, serif;
  margin-bottom: var(--space-md);
}

.page-hero p {
  font-size: 16px;
  color: rgba(255,255,255,0.85);
  max-width: 560px;
  margin: 0 auto;
}

@media (max-width: 767px) {
  .page-hero { padding: var(--space-xl) 0; }
  .page-hero h1 { font-size: 26px; }
}

/* ── 14. 工具類 ── */
.text-center { text-align: center; }
.text-muted  { color: var(--color-text-muted); }
.mt-xl       { margin-top: var(--space-xl); }
.mb-xl       { margin-bottom: var(--space-xl); }

/* 骨架屏動畫 */
@keyframes skeleton-pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.4; }
}

.skeleton {
  background: var(--color-bg-light);
  border-radius: var(--radius-sm);
  animation: skeleton-pulse 1.5s ease infinite;
}

/* ── 15. 語言切換器 ── */
.lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  background: rgba(255,255,255,.12);
  border-radius: 20px;
  padding: 3px 4px;
  margin-right: 4px;
}

.lang-switcher button {
  background: none;
  border: none;
  color: rgba(255,255,255,.65);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .04em;
  padding: 3px 8px;
  border-radius: 16px;
  cursor: pointer;
  line-height: 1;
  transition: background .2s, color .2s;
}

.lang-switcher button:hover {
  color: #fff;
}

.lang-switcher button.active {
  background: #fff;
  color: var(--color-sc);
}