/* ==========================================================================
   CHUIYU.MAIL 官网展示型设计系统 (Claude-Inspired Editorial Aesthetic)
   ========================================================================== */

:root {
  /* 基础底色与表面 (Warm Ivory & Cream Palette) */
  --canvas-bg: #FAF9F5;
  --surface-card: #FFFFFF;
  --surface-muted: #F6F4ED;
  --surface-subtle: #F0ECE1;
  --surface-hover: #F8F6EF;

  /* 边框体系 (Subtle Oat & Sand Borders) */
  --border-warm: #E4E0D5;
  --border-subtle: #EDE9DF;
  --border-strong: #C8C4B8;
  --border-focus: #D97757;

  /* 文字墨色体系 (Slate Ink & Charcoal) */
  --text-ink: #191918;
  --text-muted: #66645E;
  --text-dim: #949188;

  /* 陶土色品牌强调 (Terracotta / Clay Accent) */
  --accent-clay: #D97757;
  --accent-clay-hover: #C76646;
  --accent-clay-active: #B55637;
  --accent-clay-subtle: #FDF3EE;
  --accent-clay-border: #F1C6B6;

  /* 鼠尾草绿状态色彩 (Sage Green for Success & Active) */
  --sage-text: #3D6435;
  --sage-bg: #EFF5ED;
  --sage-border: #C8DAC3;

  /* 砖红与警告状态色彩 (Terracotta Brick Red for Danger & Errors) */
  --danger-text: #BA3D30;
  --danger-bg: #FDF3F1;
  --danger-border: #F3C7C1;

  /* 暖燕麦状态色彩 (Warm Oat for Unused / Neutral) */
  --warm-text: #96661A;
  --warm-bg: #FCF7EB;
  --warm-border: #F2E3C2;

  /* 字体回退栈 (Local Serif & Humanist Sans) */
  --font-serif: "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC", "Noto Serif SC", SimSun, "STSong", Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  /* 几何与投影 */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-pill: 9999px;
  --shadow-sm: 0 1px 3px rgba(35, 30, 20, 0.03), 0 1px 2px rgba(35, 30, 20, 0.02);
  --shadow-card: 0 4px 16px rgba(35, 30, 20, 0.04), 0 1px 3px rgba(35, 30, 20, 0.02);
  --shadow-float: 0 12px 36px rgba(35, 30, 20, 0.06), 0 2px 8px rgba(35, 30, 20, 0.03);

  /* 向后兼容变量映射 (保证既有 JS 脚本正常读取) */
  --bg-color: var(--canvas-bg);
  --surface-color: var(--surface-card);
  --border-color: var(--border-warm);
  --text-main: var(--text-ink);
  --accent-color: var(--accent-clay);
  --accent-hover: var(--accent-clay-hover);
  --danger-color: var(--danger-text);
}

/* ==========================================================================
   全局重置与无障碍基线
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--canvas-bg);
  color: var(--text-ink);
  line-height: 1.6;
  font-size: 15px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 键盘可访问焦点外框 */
:focus-visible {
  outline: 2px solid var(--accent-clay);
  outline-offset: 2px;
}

/* 尊重减弱动态效果偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ==========================================================================
   顶部导航栏 (Header Bar)
   ========================================================================== */

.header-bar {
  background-color: var(--canvas-bg);
  border-bottom: 1px solid var(--border-warm);
  padding: 16px 24px;
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
}

.header-container {
  max-width: 1160px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.header-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
}

.logo {
  font-family: var(--font-serif);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-ink);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
}

.logo-sub {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  padding-left: 10px;
  border-left: 1px solid var(--border-warm);
  letter-spacing: 0.01em;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.header-nav-link {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.header-nav-link:hover {
  color: var(--text-ink);
}

.buy-info {
  font-size: 12px;
  font-weight: 500;
  color: var(--accent-clay);
  background-color: var(--accent-clay-subtle);
  border: 1px solid var(--accent-clay-border);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  display: inline-block;
  white-space: nowrap;
}

/* ==========================================================================
   主容器布局 (Main Layout)
   ========================================================================== */

.container {
  max-width: 1160px;
  width: 100%;
  margin: 0 auto;
  padding: 40px 24px 60px;
  flex: 1;
}

/* ==========================================================================
   官网展示型主视觉区域 (Hero & Exchange Showcase)
   ========================================================================== */

.hero-showcase {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 48px;
  padding: 24px 0 64px;
}

.hero-text-block {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  background-color: var(--surface-muted);
  border: 1px solid var(--border-warm);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
}

.hero-badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-clay);
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 46px;
  line-height: 1.22;
  font-weight: 600;
  color: var(--text-ink);
  letter-spacing: -0.025em;
  word-break: break-word;
}

.hero-desc {
  font-size: 17px;
  line-height: 1.68;
  color: var(--text-muted);
  max-width: 540px;
}

.hero-value-points {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 8px;
  padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
}

.value-point-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
}

.value-point-icon {
  width: 16px;
  height: 16px;
  color: var(--accent-clay);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* ==========================================================================
   卡片与容器组件 (Cards & Panels)
   ========================================================================== */

.card {
  background-color: var(--surface-card);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
  margin-bottom: 28px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  border-color: var(--border-strong);
}

.card-exchange {
  background-color: var(--surface-card);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  box-shadow: var(--shadow-float);
  position: relative;
}

.card-title {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text-ink);
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.card-description {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.card-padded {
  padding: 28px;
}

.card-auth {
  max-width: 480px;
  margin: 50px auto;
  box-shadow: var(--shadow-float);
}

/* ==========================================================================
   表单控件与按钮 (Form Controls & Buttons)
   ========================================================================== */

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-ink);
  margin-bottom: 8px;
  letter-spacing: 0.01em;
}

.input-text, .input-select, .input-textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-md);
  background-color: var(--surface-card);
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text-ink);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.input-text::placeholder {
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 13px;
}

.input-text:hover, .input-select:hover, .input-textarea:hover {
  border-color: var(--border-strong);
}

.input-text:focus, .input-select:focus, .input-textarea:focus {
  border-color: var(--accent-clay);
  box-shadow: 0 0 0 3px rgba(217, 119, 87, 0.15);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.05s ease;
  user-select: none;
  text-decoration: none;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.btn:active {
  transform: translateY(1px);
}

/* 收件工作区不显示指向已隐藏首页区块的导航。 */
body:has(#mailbox-section:not(.hidden)) .header-nav-link,
body:has(#mailbox-section:not(.hidden)) .footer-link[href^="#"] {
  display: none;
}

.btn-primary {
  background-color: #a84f35;
  color: #FFFFFF;
  border-color: #a84f35;
  box-shadow: 0 1px 3px rgba(217, 119, 87, 0.25);
}

.btn-primary:hover {
  background-color: #8e412c;
  border-color: #8e412c;
}

.btn-secondary {
  background-color: var(--surface-card);
  color: var(--text-ink);
  border-color: var(--border-warm);
}

.btn-secondary:hover {
  background-color: var(--surface-muted);
  border-color: var(--border-strong);
}

.btn-danger {
  background-color: var(--surface-card);
  color: var(--danger-text);
  border-color: var(--danger-border);
}

.btn-danger:hover {
  background-color: var(--danger-bg);
  border-color: var(--danger-text);
}

.btn-sm {
  padding: 7px 14px;
  font-size: 13px;
  border-radius: var(--radius-sm);
}

.btn-block {
  width: 100%;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

.form-actions {
  display: flex;
  gap: 14px;
  align-items: center;
  margin-top: 24px;
  flex-wrap: wrap;
}

.form-actions-full {
  margin-top: 24px;
}

.loading-text {
  font-size: 13px;
  color: var(--text-muted);
}

/* ==========================================================================
   提示条与徽章 (Alerts & Badges)
   ========================================================================== */

.alert {
  padding: 12px 18px;
  margin-bottom: 20px;
  font-size: 13.5px;
  line-height: 1.5;
  border-radius: var(--radius-md);
  border: 1px solid;
}

.alert-info {
  background-color: var(--surface-muted);
  border-color: var(--border-warm);
  color: var(--text-ink);
}

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

.alert-success {
  background-color: var(--sage-bg);
  border-color: var(--sage-border);
  color: var(--sage-text);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  white-space: nowrap;
}

.badge-active {
  background-color: var(--sage-bg);
  color: var(--sage-text);
  border-color: var(--sage-border);
}

.badge-expired {
  background-color: var(--surface-subtle);
  color: var(--text-muted);
  border-color: var(--border-warm);
}

.badge-disabled {
  background-color: var(--danger-bg);
  color: var(--danger-text);
  border-color: var(--danger-border);
}

.badge-unused {
  background-color: var(--warm-bg);
  color: var(--warm-text);
  border-color: var(--warm-border);
}

.badge-subtle {
  background-color: var(--surface-muted);
  color: var(--text-muted);
  border-color: var(--border-warm);
}

/* ==========================================================================
   首页功能流程与说明板块 (Three-Step Process & FAQs)
   ========================================================================== */

.process-section {
  margin-top: 24px;
  padding-top: 48px;
  border-top: 1px solid var(--border-warm);
}

.section-head {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 40px;
}

.section-tag {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--accent-clay);
  margin-bottom: 8px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text-ink);
  margin-bottom: 10px;
}

.section-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.step-card {
  background-color: var(--surface-card);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.step-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-strong);
}

.step-number {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-clay);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-pill);
  background-color: var(--accent-clay-subtle);
  border: 1px solid var(--accent-clay-border);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 4px;
}

.step-title {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-ink);
  letter-spacing: -0.01em;
}

.step-desc {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-muted);
}

.guidelines-box {
  background-color: var(--surface-muted);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.guidelines-title {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-ink);
  margin-bottom: 16px;
}

.guidelines-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.guideline-item-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-ink);
  margin-bottom: 6px;
}

.guideline-item-desc {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-muted);
}

/* ==========================================================================
   邮箱控制面板 (Mailbox Workspace)
   ========================================================================== */

.mailbox-banner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  background-color: var(--surface-card);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-card);
}

.mailbox-address-wrapper {
  flex: 1;
  min-width: 280px;
}

.mailbox-address-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.mailbox-address-val {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  color: var(--text-ink);
  word-break: break-all;
  letter-spacing: -0.01em;
}

.action-row {
  margin-top: 14px;
  display: flex;
  gap: 12px;
  align-items: center;
}

.toast-success {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--sage-text);
  background-color: var(--sage-bg);
  border: 1px solid var(--sage-border);
  padding: 4px 10px;
  border-radius: var(--radius-pill);
}

.mailbox-timer-wrapper {
  text-align: right;
  min-width: 160px;
}

.timer-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.timer-clock {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  color: var(--accent-clay);
  letter-spacing: 0.02em;
}

.timer-subtext {
  font-size: 12px;
  color: var(--text-dim);
  margin-top: 4px;
}

.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.poll-status {
  font-size: 12.5px;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ==========================================================================
   邮件列表与详情渲染 (Message List & Verification Code)
   ========================================================================== */

.message-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.message-item {
  border: 1px solid var(--border-warm);
  background-color: var(--surface-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.message-item:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-card);
}

.message-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.message-sender {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-ink);
}

.message-time {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.message-subject {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  color: var(--text-ink);
  letter-spacing: -0.01em;
  margin-bottom: 14px;
}

.code-box {
  background-color: var(--accent-clay-subtle);
  border: 1px solid var(--accent-clay-border);
  border-left: 4px solid var(--accent-clay);
  border-radius: var(--radius-sm);
  padding: 12px 18px;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.code-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent-clay);
}

.code-value {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 3px;
  color: var(--accent-clay-active);
}

.message-body {
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.6;
  color: #383632;
  background-color: var(--surface-muted);
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-sm);
  padding: 16px;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 260px;
  overflow-y: auto;
}

.empty-state {
  text-align: center;
  padding: 56px 20px;
  color: var(--text-muted);
}

.empty-state-icon {
  font-size: 36px;
  margin-bottom: 12px;
}

.empty-state-title {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-ink);
  margin-bottom: 6px;
}

.empty-state-desc {
  font-size: 13.5px;
  color: var(--text-muted);
  max-width: 440px;
  margin: 0 auto;
}

/* ==========================================================================
   管理后台控制台 (Admin Dashboard)
   ========================================================================== */

.issue-form-row {
  display: flex;
  gap: 14px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.input-count-wrapper {
  width: 160px;
}

.export-box {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border-warm);
}

.export-actions {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.export-textarea {
  width: 100%;
  height: 150px;
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 14px;
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-md);
  background-color: var(--surface-muted);
  color: var(--text-ink);
  outline: none;
}

.table-container {
  overflow-x: auto;
  border: 1px solid var(--border-warm);
  border-radius: var(--radius-md);
  margin-top: 14px;
  background-color: var(--surface-card);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 13px;
}

.data-table th, .data-table td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--border-subtle);
}

.data-table th {
  background-color: var(--surface-muted);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.05em;
}

.data-table tr:last-child td {
  border-bottom: none;
}

.data-table tr:hover {
  background-color: var(--surface-hover);
}

.table-pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 18px;
}

.page-indicator {
  font-size: 13px;
  color: var(--text-muted);
}

.pagination-buttons {
  display: flex;
  gap: 8px;
}

.font-mono {
  font-family: var(--font-mono);
}

.d-flex-center-gap {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ==========================================================================
   页脚 (Footer)
   ========================================================================== */

.footer-bar {
  border-top: 1px solid var(--border-warm);
  background-color: var(--canvas-bg);
  padding: 28px 24px;
  margin-top: auto;
}

.footer-container {
  max-width: 1160px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.footer-logo {
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 700;
  color: var(--text-ink);
}

.footer-desc {
  font-size: 12px;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 18px;
}

.footer-link {
  font-size: 12.5px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.footer-link:hover {
  color: var(--text-ink);
}

/* ==========================================================================
   实用类与响应式断点 (Utilities & Responsive)
   ========================================================================== */

.hidden {
  display: none !important;
}

.text-success {
  color: var(--success, #2e7d32);
}

/* 地址池统计看板卡片 */
.pool-metrics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 16px;
  margin-top: 16px;
  padding: 16px;
  background-color: var(--surface-secondary, #faf9f5);
  border-radius: var(--radius-md, 8px);
  border: 1px solid var(--border-warm, #e8e6df);
}

.pool-metric-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.pool-metric-label {
  font-size: 13px;
  color: var(--text-muted, #6f6e69);
}

.pool-metric-value {
  font-size: 22px;
  font-weight: 700;
  font-family: var(--font-mono, monospace);
  color: var(--text-primary, #1b1b18);
}


/* 平板与窄屏响应 (<= 960px) */
@media (max-width: 960px) {
  .hero-showcase {
    grid-template-columns: 1fr;
    gap: 36px;
    padding: 16px 0 48px;
  }

  .hero-title {
    font-size: 36px;
  }

  .steps-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .guidelines-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
}

/* 手机端响应 (<= 640px) */
@media (max-width: 640px) {
  .header-bar {
    padding: 14px 16px;
  }

  .header-container {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .container {
    padding: 24px 16px 40px;
  }

  .hero-title {
    font-size: 30px;
    line-height: 1.25;
  }

  .hero-desc {
    font-size: 15px;
  }

  .card-exchange, .card {
    padding: 24px 18px;
  }

  .mailbox-banner {
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 18px;
  }

  .mailbox-timer-wrapper {
    text-align: left;
  }

  .mailbox-address-val {
    font-size: 18px;
  }

  .toolbar {
    flex-direction: column;
    align-items: stretch;
  }

  .toolbar-left {
    justify-content: space-between;
  }

  .btn-sm {
    padding: 8px 14px;
  }

  .code-box {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-container {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* 极窄屏幕断点 (320px ~ 375px) - 严格防止横向溢出 */
@media (max-width: 375px) {
  .hero-title {
    font-size: 26px;
  }

  .btn {
    width: 100%;
  }

  .action-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .form-actions {
    flex-direction: column;
    align-items: stretch;
  }
}