/* ============================================================
   Hub 通用設計系統 — style.css v1.0
   優美現代風格：深色漸變 + 玻璃卡片 + 柔和光效
   適用：hub 主頁 + 所有工具頁面
   ============================================================ */

:root {
  /* 色彩系統 */
  --bg-deep: #0a0a1a;
  --bg-base: #12122a;
  --card-bg: rgba(255, 255, 255, 0.05);
  --card-border: rgba(255, 255, 255, 0.10);
  --card-hover: rgba(255, 255, 255, 0.09);
  --text-primary: #f1f5f9;
  --text-secondary: #a3aec2;
  --text-muted: #6b7a90;
  --accent-1: #6366f1;   /* indigo */
  --accent-2: #a855f7;   /* violet */
  --accent-3: #22d3ee;   /* cyan */
  --success: #34d399;
  --danger: #f87171;

  /* 字體 */
  --font-display: "Inter", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;

  /* 尺寸 */
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.25);
}

/* ---------- 基礎 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background: var(--bg-deep);
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 背景裝飾：漸變光暈 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(ellipse 60% 40% at 15% 0%, rgba(99, 102, 241, 0.18), transparent 60%),
    radial-gradient(ellipse 50% 40% at 85% 20%, rgba(168, 85, 247, 0.14), transparent 60%),
    radial-gradient(ellipse 40% 30% at 50% 100%, rgba(34, 211, 238, 0.10), transparent 60%),
    linear-gradient(180deg, var(--bg-deep) 0%, var(--bg-base) 100%);
  background-attachment: fixed;
}

/* 微細格紋點綴 */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image: radial-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 28px 28px;
  pointer-events: none;
}

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

/* ---------- 容器 ----------
   寬屏策略：盡量用盡空間（max-width 只喺超寬屏 4K 先限）
   1920px 屏幕 → 接近 full width，左右唔留白 */
.container {
  width: 100%;
  max-width: min(1760px, 97vw);
  margin: 0 auto;
  padding: clamp(24px, 4vw, 48px) clamp(16px, 3vw, 40px) clamp(40px, 6vw, 72px);
}

/* ---------- 響應式斷點系統 ----------
   統一斷點（Mia 設計規範，2026-08-12）：
   ≥1200px  桌面寬屏    → 多欄，空間用盡
   900-1199 平板/筆電  → 欄位 fluid 收窄（clamp 自動）
   <900px   手機豎屏   → 單欄堆疊，sidebar 轉置頂
   斷點全部用 CSS variables 管理，新頁面必須跟隨
------------------------------------------ */
:root {
  --bp-desktop: 1200px;
  --bp-tablet: 900px;
}

/* ---------- Hero ---------- */
.hero {
  text-align: center;
  padding: clamp(36px, 6vw, 64px) 0 clamp(28px, 4vw, 48px);
}

.hero .logo {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 14px;
}

.hero h1 .gradient {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2), var(--accent-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p.subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
}

/* ---------- 工具卡片網格 ----------
   寬屏 4 欄（Mia 要求），響應式縮減：4 → 3 → 2 → 1 */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(14px, 2vw, 24px);
  margin-top: 12px;
}

@media (max-width: 1280px) { .tools-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 960px)  { .tools-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px)  { .tools-grid { grid-template-columns: 1fr; } }

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

.tool-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 28px 26px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--shadow-card);
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, border-color 0.25s ease;
  overflow: hidden;
}

.tool-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2), var(--accent-3));
  opacity: 0;
  transition: opacity 0.25s ease;
}

.tool-card:hover {
  transform: translateY(-5px);
  background: var(--card-hover);
  border-color: rgba(255, 255, 255, 0.18);
  box-shadow: var(--shadow-card), var(--shadow-glow);
}

.tool-card:hover::before { opacity: 1; }

.tool-card .icon {
  font-size: 2.1rem;
  line-height: 1;
  filter: drop-shadow(0 4px 12px rgba(99, 102, 241, 0.35));
}

.tool-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
}

.tool-card p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  flex: 1;
}

.tool-card .arrow {
  align-self: flex-end;
  font-size: 1.05rem;
  color: var(--text-muted);
  transition: transform 0.25s ease, color 0.25s ease;
}

.tool-card:hover .arrow {
  transform: translateX(5px);
  color: var(--accent-3);
}

/* ---------- 工具頁面 ---------- */
.tool-page {
  max-width: 960px;
  margin: 0 auto;
}

/* 寬版工具頁（有側欄 / 需要橫向空間，如 YouTube 下載器） */
.tool-page-wide {
  max-width: min(1600px, 100%);
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 24px;
}

.page-header .back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  transition: all 0.2s ease;
}

.page-header .back:hover {
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.25);
  background: var(--card-hover);
  transform: translateX(-3px);
}

.page-title {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 800;
  text-align: center;
  margin-bottom: 8px;
}

.page-desc {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.98rem;
  margin-bottom: 32px;
}

/* ---------- 面板卡片 ---------- */
.panel {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--shadow-card);
  padding: 30px;
}

/* ---------- 表單元件 ---------- */
.field { margin-bottom: 18px; }

.field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
  letter-spacing: 0.03em;
}

.input, .select, .textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 0.98rem;
  font-family: var(--font-body);
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.input:focus, .select:focus, .textarea:focus {
  border-color: var(--accent-1);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
  background: rgba(255, 255, 255, 0.08);
}

.input::placeholder, .textarea::placeholder { color: var(--text-muted); }

/* select 原生 dropdown 修正：防止白底白字 */
.select {
  color-scheme: dark;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a3aec2' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 16px;
  padding-right: 42px;
}

.select option {
  background: var(--bg-base);
  color: var(--text-primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 0.98rem;
  font-weight: 700;
  font-family: var(--font-body);
  color: #fff;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.2s ease, filter 0.2s ease;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

.btn:hover {
  transform: translateY(-2px);
  filter: brightness(1.1);
  box-shadow: 0 6px 24px rgba(99, 102, 241, 0.45);
}

.btn:active { transform: translateY(0); }

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--card-border);
  box-shadow: none;
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.14);
  box-shadow: none;
  filter: none;
}

.btn-full { width: 100%; }

/* ---------- 結果 / 預覽區 ---------- */
.result-box {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--card-border);
  text-align: center;
}

/* 雙欄工具佈局（寬屏用盡空間，手機單欄）：
   左：表單輸入，右：預覽結果 */
.qr-layout {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 4fr);
  gap: clamp(16px, 3vw, 44px);
  align-items: start;
}

.qr-layout .qr-preview .result-box {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
  position: sticky;
  top: 24px;
}

.result-placeholder {
  padding: 36px 16px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.qr-canvas-wrap {
  display: inline-flex;
  padding: 14px;
  background: #fff;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}

.qr-canvas-wrap img, .qr-canvas-wrap canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

.result-meta {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  word-break: break-all;
  min-height: 1.4em;
}

/* ---------- Footer ---------- */
.footer {
  text-align: center;
  padding: 40px 0 20px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer .dot { color: var(--accent-3); }

/* ---------- 動畫 ---------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

.fade-up {
  animation: fadeUp 0.6s ease both;
}

.fade-up.delay-1 { animation-delay: 0.08s; }
.fade-up.delay-2 { animation-delay: 0.16s; }
.fade-up.delay-3 { animation-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- 響應式 ---------- */
/* 手機豎屏：單欄堆疊 */
@media (max-width: 900px) {
  .container { padding: 20px 16px 48px; }
  .hero { padding: 28px 0 24px; }
  .panel { padding: clamp(18px, 4vw, 24px); }
  .page-header { flex-direction: column; align-items: flex-start; }
  .tool-page, .tool-page-wide { max-width: 100%; }
  .qr-layout { grid-template-columns: 1fr; }
  .qr-layout .qr-preview .result-box {
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--card-border);
    position: static;
  }
}

/* 超窄屏（<400px）：進一步壓縮 */
@media (max-width: 400px) {
  .hero h1 { font-size: 1.7rem; }
  .btn { padding: 11px 16px; font-size: 0.92rem; }
}