/* ==========================================================================
   Muse 邀请码互助站 - Meta Family Design System (Facebook / Threads / Messenger)
   重构升级特征：
   - 浅灰底色 (#F0F2F5) + 纯白卡片 (#FFFFFF) + 克制边框 (#E4E6EB / #CED0D4)
   - 标志性 Meta 交互蓝 (#0866FF) 与清晰语义状态色
   - 新增「随机抽码转盘池 (Lucky Referral Pool)」聚焦卡与 30 名额可视化进度条
   - 严格满足桌面端、平板与手机端响应式布局及 WCAG AA 无障碍对比度
   ========================================================================== */

:root {
  color-scheme: light dark;

  --bg-canvas: #F0F2F5;
  --bg-surface: #FFFFFF;
  --bg-subtle: #F7F8FA;
  --bg-hover: #F2F3F5;
  --bg-active: #E4E6EB;
  --bg-active-hover: #D8DADF;

  --text-primary: #050505;
  --text-secondary: #4B4F56;
  --text-muted: #65676B;

  --border-subtle: #E4E6EB;
  --border-strong: #CED0D4;
  --border-hover: #8A8D91;

  --brand-primary: #0866FF;
  --brand-primary-hover: #0054E0;
  --brand-primary-soft: #E7F3FF;
  --brand-primary-text: #0051D5;
  --brand-primary-soft-hover: #D6E9FF;
  --brand-border: #B2D4FF;

  --status-available-bg: #EBF7EE;
  --status-available-text: #1B6E2D;
  --status-available-border: #B7E1C1;
  --status-available-hover: #DDF2E2;

  --status-used-bg: #F0F2F5;
  --status-used-text: #4B4F56;
  --status-used-border: #CED0D4;

  --status-expired-bg: #FDECEE;
  --status-expired-text: #B41E30;
  --status-expired-border: #F5B7BF;

  --warning-bg: #FEF6E6;
  --warning-text: #8A5300;
  --warning-border: #F5D491;

  --danger-text: #C91B2E;
  --danger-bg: #FFF0F2;

  --toast-bg: #1C1E21;
  --toast-error-bg: #7F1D1D;
  --toast-success-text: #4ADE80;
  --toast-error-text: #FCA5A5;
  --skeleton-base: #E9EBEF;
  --skeleton-shine: #F4F5F7;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 9999px;

  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.08);
  --shadow-elevated: 0 8px 24px rgba(0, 0, 0, 0.12), 0 1px 3px rgba(0, 0, 0, 0.08);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

/* 跟随系统深色模式；无需手动切换。 */
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;

    --bg-canvas: #0B0D10;
    --bg-surface: #151A21;
    --bg-subtle: #1B212A;
    --bg-hover: #222933;
    --bg-active: #2A323D;
    --bg-active-hover: #343D49;

    --text-primary: #E8EAED;
    --text-secondary: #B7BDC6;
    --text-muted: #8B93A0;

    --border-subtle: #2A313B;
    --border-strong: #3B4552;
    --border-hover: #586372;

    --brand-primary: #2F6FED;
    --brand-primary-hover: #4A82F5;
    --brand-primary-soft: #16263D;
    --brand-primary-text: #8AB6FF;
    --brand-primary-soft-hover: #1D3352;
    --brand-border: #2B5A96;

    --status-available-bg: #102319;
    --status-available-text: #6FE39A;
    --status-available-border: #245536;
    --status-available-hover: #163322;

    --status-used-bg: #1B212A;
    --status-used-text: #B7BDC6;
    --status-used-border: #3B4552;

    --status-expired-bg: #2A1216;
    --status-expired-text: #FF8B9A;
    --status-expired-border: #5A2430;

    --warning-bg: #2A2111;
    --warning-text: #F3C46A;
    --warning-border: #5A4720;

    --danger-text: #FF8B9A;
    --danger-bg: #2A1216;

    --toast-bg: #242C36;
    --toast-error-bg: #5A1F27;
    --toast-success-text: #6FE39A;
    --toast-error-text: #FFB3BD;
    --skeleton-base: #1B212A;
    --skeleton-shine: #242C36;

    --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.45);
    --shadow-elevated: 0 10px 30px rgba(0, 0, 0, 0.6);
  }
}

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

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background-color: var(--bg-canvas);
}

body {
  margin: 0;
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

:focus-visible {
  outline: 2px solid var(--brand-primary);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 999;
  padding: 8px 16px;
  background: var(--brand-primary);
  color: #FFFFFF;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
}

.skip-link:focus {
  top: 12px;
}

/* 顶部独立社区声明条 */
.top-notice-bar {
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  font-size: 13px;
  color: var(--text-secondary);
}

.top-notice-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.header-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background-color: var(--brand-primary);
  color: #FFFFFF;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 18px;
  flex-shrink: 0;
}

/* 英雄区双栏布局（左侧产品价值与兑换步骤速览，右侧随机抽码转盘卡） */
.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 20px;
  align-items: stretch;
}

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

/* 随机抽码聚焦框 */
.spotlight-pool-box {
  background-color: var(--bg-subtle);
  border: 1.5px solid var(--brand-border);
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
}

.spotlight-code-display {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 0.05em;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  border: 1.5px dashed var(--brand-primary);
  color: var(--text-primary);
  text-align: center;
  word-break: break-all;
}

/* 列表卡片邀请码胶囊 */
.code-pill {
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.04em;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-subtle);
  border: 1px dashed var(--border-strong);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  word-break: break-all;
}

.code-pill.is-unavailable {
  text-decoration: line-through;
  color: var(--text-muted);
  background-color: var(--bg-subtle);
}

/* 30 名额可视化进度条 */
.quota-bar-track {
  width: 100%;
  height: 7px;
  background-color: var(--bg-active);
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.quota-bar-fill {
  height: 100%;
  border-radius: var(--radius-pill);
  transition: width 0.25s ease;
}

/* 状态徽章 */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  font-size: 12.5px;
  font-weight: 600;
  line-height: 1.2;
  border: 1px solid transparent;
  white-space: nowrap;
}

.status-badge.status-available {
  background-color: var(--status-available-bg);
  color: var(--status-available-text);
  border-color: var(--status-available-border);
}

.status-badge.status-used {
  background-color: var(--status-used-bg);
  color: var(--status-used-text);
  border-color: var(--status-used-border);
}

.status-badge.status-expired {
  background-color: var(--status-expired-bg);
  color: var(--status-expired-text);
  border-color: var(--status-expired-border);
}

/* 通用按钮系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.3;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 0.14s ease, border-color 0.14s ease, color 0.14s ease;
  text-decoration: none;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn-primary {
  background-color: var(--brand-primary);
  color: #FFFFFF;
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--brand-primary-hover);
}

.join-muse-btn {
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
  padding: 12px 16px;
  font-size: 16px;
}

.btn-secondary {
  background-color: var(--bg-active);
  color: var(--text-primary);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--bg-active-hover);
}

.btn-soft {
  background-color: var(--brand-primary-soft);
  color: var(--brand-primary-text);
}

.btn-soft:hover:not(:disabled) {
  background-color: var(--brand-primary-soft-hover);
}

.btn-success-soft {
  background-color: var(--status-available-bg);
  color: var(--status-available-text);
  border-color: var(--status-available-border);
}

.btn-success-soft:hover:not(:disabled) {
  background-color: var(--status-available-hover);
}

.btn-outline {
  background-color: var(--bg-surface);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn-outline:hover:not(:disabled) {
  background-color: var(--bg-hover);
}

/* 卡片与表单控件 */
.meta-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}

.input-field {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  font-size: 14.5px;
  font-family: inherit;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.input-field:hover {
  border-color: var(--border-hover);
}

.input-field:focus {
  outline: none;
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px rgba(8, 102, 255, 0.16);
}

.input-field.has-error {
  border-color: var(--danger-text);
  background-color: var(--danger-bg);
}

/* 弹窗遮罩 */
.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 80;
  background-color: rgba(5, 5, 5, 0.52);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal-panel {
  width: 100%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  background-color: var(--bg-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-elevated);
  border: 1px solid var(--border-subtle);
}

/* 轻提示 Toast */
.toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 95;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: calc(100vw - 32px);
}

.toast-item {
  background-color: var(--toast-bg);
  color: #FFFFFF;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-elevated);
  font-size: 13.5px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toast-item.is-error {
  background-color: var(--toast-error-bg);
}

/* 加载占位 */
.skeleton {
  border-radius: 6px;
  background: linear-gradient(
    90deg,
    var(--skeleton-base) 25%,
    var(--skeleton-shine) 37%,
    var(--skeleton-base) 63%
  );
  background-size: 400% 100%;
  animation: skeleton-shimmer 1.2s ease infinite;
}

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

@media (prefers-reduced-motion: reduce) {
  .skeleton {
    animation: none;
  }
}

@media (max-width: 640px) {
  .toast-container {
    left: 16px;
    right: 16px;
    bottom: 16px;
  }
}