/* ============================================================
   Office 365 E3 领取中心 · 前端样式
   参考 Notion + Vercel：暖白底、近黑文字、深色主按钮、极细边框
   无渐变、无毛玻璃、无 emoji 图标
   响应式：移动端优先，平板/桌面逐步展开
   ============================================================ */

:root {
  /* 颜色 — 扁平，无渐变 */
  --bg: #f7f7f5;            /* 暖白页面底 */
  --surface: #ffffff;       /* 卡片表面 */
  --surface-2: #fafaf9;     /* 次级表面 / 输入底 */
  --text: rgba(0, 0, 0, 0.92);
  --text-2: #6b6b66;        /* 次要文字 */
  --text-3: rgba(0, 0, 0, 0.4);

  --accent: #0075de;        /* 仅用于链接与 focus */
  --accent-hover: #0066c0;
  --accent-soft: rgba(0, 117, 222, 0.08);

  --ink: #171717;           /* 深色主按钮 */
  --ink-hover: #2b2b2b;

  --border: rgba(0, 0, 0, 0.1);
  --border-strong: rgba(0, 0, 0, 0.16);

  --danger: #c0392b;
  --danger-soft: rgba(192, 57, 43, 0.06);
  --danger-border: rgba(192, 57, 43, 0.2);
  --warn: #9a6b1f;
  --warn-soft: #faf6ee;
  --warn-border: #e6d3a8;
  --success: #16a34a;

  /* Office 产品标志色（仅文字与极浅底色，无渐变） */
  --c-word: #2b579a;
  --c-excel: #217346;
  --c-powerpoint: #c43e1c;
  --c-outlook: #0378c3;
  --c-teams: #5059c9;
  --c-onedrive: #0364b8;

  /* 阴影 — 单层、低透明度 */
  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-2: 0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(0, 0, 0, 0.04);
  --shadow-3: 0 2px 6px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.06);

  /* 圆角 — 偏小，更克制 */
  --r: 12px;
  --r-sm: 6px;
  --r-lg: 14px;

  /* 响应式宽度 */
  --maxw: 520px;
  --maxw-lg: 820px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  font-weight: 400;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---------- Header ---------- */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-inner {
  max-width: var(--maxw-lg);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.01em;
}
.brand-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 7px;
  background: var(--ink);
  color: #fff;
}
.brand-logo svg { width: 15px; height: 15px; }
.brand-name { color: var(--text); }
.brand-name strong {
  font-weight: 700;
  color: var(--text);
}

/* ---------- Header 操作区 ---------- */
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.remaining {
  font-weight: 500;
  font-size: 13px;
  color: var(--text-2);
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.remaining-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--success);
  display: inline-block;
}
.remaining #remaining {
  color: var(--text);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ---------- 图标按钮 ---------- */
.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text-2);
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.icon-btn:hover,
.icon-btn:focus-visible {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--surface-2);
  outline: none;
}
.icon-btn svg { width: 17px; height: 17px; }

/* ---------- 公众号引导按钮（带文案） ---------- */
.mp-hint {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-weight: 500;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.mp-hint:hover,
.mp-hint:focus-visible {
  border-color: var(--border-strong);
  background: var(--surface-2);
  outline: none;
}
.mp-hint svg { width: 16px; height: 16px; color: var(--text-2); flex-shrink: 0; }
.mp-hint-short { display: none; }

/* ---------- 二维码按钮 + 独立弹层 ---------- */
.qr-btn {
  position: relative;
  display: inline-flex;
}
.popover {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 50;
  width: 256px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--shadow-3);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity 0.16s ease, transform 0.16s ease, visibility 0.16s ease;
}
.qr-btn.is-open .popover {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}
.popover-arrow {
  position: absolute;
  top: -5px;
  right: 14px;
  width: 10px;
  height: 10px;
  background: var(--surface);
  border-left: 1px solid var(--border);
  border-top: 1px solid var(--border);
  transform: rotate(45deg);
}
.popover-img {
  display: block;
  width: 224px;
  height: 224px;
  object-fit: cover;
  background: var(--surface-2);
  border-radius: var(--r-sm);
}
.popover-label {
  margin: 0;
  text-align: center;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-2);
}

/* ---------- Main ---------- */
.main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 36px 20px 52px;
}
.card {
  background: var(--surface);
  border-radius: var(--r);
  padding: 32px;
  box-shadow: var(--shadow-2);
  border: 1px solid var(--border);
  position: relative;
}

/* 视图切换 */
.view { animation: fade 0.22s ease both; }
@keyframes fade {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Hero ---------- */
.hero { margin-bottom: 24px; }
.eyebrow {
  margin: 0 0 12px;
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--text-2);
}
.hero-title {
  margin: 0 0 8px;
  font-weight: 700;
  font-size: 28px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
}
.hero-sub {
  margin: 0;
  font-weight: 400;
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.6;
}

/* ---------- 产品展示 ---------- */
.products {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 28px;
}
.product {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 7px;
  font-weight: 500;
  font-size: 13px;
  color: var(--c, var(--text));
  background: var(--c-soft, var(--surface-2));
  border: 1px solid var(--c-border, var(--border));
}
.product-icon { width: 15px; height: 15px; flex-shrink: 0; }

/* 各产品标志色 — 仅文字与极浅底，无 hover 动效 */
.product--word      { --c: var(--c-word);       --c-soft: #f1f4f9; --c-border: rgba(43,87,154,.16); }
.product--excel     { --c: var(--c-excel);      --c-soft: #f0f5f1; --c-border: rgba(33,115,70,.16); }
.product--powerpoint{ --c: var(--c-powerpoint); --c-soft: #f9f0ee; --c-border: rgba(196,62,28,.16); }
.product--outlook   { --c: var(--c-outlook);    --c-soft: #eef4fa; --c-border: rgba(3,120,195,.16); }
.product--teams     { --c: var(--c-teams);      --c-soft: #f0f0fa; --c-border: rgba(80,89,201,.16); }
.product--onedrive  { --c: var(--c-onedrive);   --c-soft: #eef3fa; --c-border: rgba(3,100,184,.16); }

/* ---------- 表单 ---------- */
.form { display: flex; flex-direction: column; }
.field-label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  font-size: 13px;
  color: var(--text-2);
}
.code-input {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 16px;
}
.code-input input {
  width: 100%;
  min-width: 0;
  flex: 1 1 auto;
  max-width: 160px;
  text-align: center;
  font-family: "Inter", ui-monospace, SFMono-Regular, Menlo, monospace;
  font-weight: 600;
  font-size: 24px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  padding: 15px 8px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-sm);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
.code-input input::placeholder {
  color: var(--text-3);
  font-weight: 400;
  letter-spacing: 0.1em;
}
.code-input input:focus {
  border-color: var(--accent);
  background: var(--surface);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.code-dash {
  font-weight: 400;
  font-size: 22px;
  color: var(--text-3);
  flex: 0 0 auto;
}
.form-hint {
  margin: 12px 0 0;
  font-size: 12px;
  color: var(--text-3);
}

/* 错误提示 */
.error-msg {
  font-size: 13px;
  color: var(--danger);
  background: var(--danger-soft);
  border: 1px solid var(--danger-border);
  border-radius: var(--r-sm);
  padding: 10px 12px;
  margin-bottom: 12px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-weight: 600;
  font-size: 15px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease, box-shadow 0.15s ease;
}
.btn:active { transform: translateY(1px); }
.btn-block { width: 100%; }
.btn-icon { width: 18px; height: 18px; flex-shrink: 0; }

/* 主按钮 — 深色实色，无渐变无彩色阴影 */
.btn-primary {
  background: var(--ink);
  color: #fff;
  padding: 13px 20px;
  box-shadow: var(--shadow-1);
}
.btn-primary:hover {
  background: var(--ink-hover);
}
.btn-primary:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(23, 23, 23, 0.18);
}
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; box-shadow: none; }
.btn-arrow { width: 16px; height: 16px; }

.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border-strong);
  padding: 11px 20px;
  margin-top: 10px;
  font-weight: 500;
}
.btn-ghost:hover { background: var(--surface-2); border-color: var(--border-strong); }
.btn-ghost svg { width: 16px; height: 16px; }

/* spinner */
.btn-spinner {
  width: 16px; height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  flex-shrink: 0;
}
.big-spinner {
  display: block;
  width: 38px; height: 38px;
  margin: 6px auto 18px;
  color: var(--text-2);
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading-text { text-align: center; color: var(--text-2); font-size: 14px; margin: 0; }

/* ---------- 成功视图 ---------- */
.success-head { text-align: center; margin-bottom: 22px; }
.success-check {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px; height: 52px;
  border-radius: 50%;
  color: #fff;
  background: var(--success);
  margin-bottom: 14px;
}
.success-check svg { width: 28px; height: 28px; }
.success-title {
  margin: 0 0 4px;
  font-weight: 700;
  font-size: 24px;
  letter-spacing: -0.02em;
}
.success-sub { margin: 0; font-size: 14px; color: var(--text-2); }

/* 凭据 */
.credentials {
  border: 1px solid var(--border-strong);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--surface-2);
}
.cred-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
}
.cred-row + .cred-row { border-top: 1px solid var(--border); }
.cred-label {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 7px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-2);
}
.cred-label svg { width: 15px; height: 15px; }
.cred-label-text {
  flex: 0 0 auto;
  font-weight: 500;
  font-size: 13px;
  color: var(--text-2);
}
.cred-value {
  flex: 1 1 auto;
  min-width: 0;
  word-break: break-all;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-weight: 600;
  font-size: 14px;
  color: var(--text);
}
.btn-copy {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 5px 11px;
  font-family: inherit;
  font-weight: 500;
  font-size: 12px;
  color: var(--text-2);
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.btn-copy:hover { color: var(--text); border-color: var(--border-strong); }
.btn-copy.copied { color: var(--success); border-color: rgba(22,163,74,.3); }

/* 警示条 */
.warning {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  font-size: 13px;
  color: var(--warn);
  background: var(--warn-soft);
  border: 1px solid var(--warn-border);
  padding: 11px 13px;
  border-radius: var(--r-sm);
  margin: 18px 0;
}
.warning svg { width: 17px; height: 17px; flex-shrink: 0; margin-top: 1px; color: var(--warn); }

/* 领取前封号风险提示 — 比普通警示更醒目（红底） */
.warning--strong {
  color: var(--danger);
  background: var(--danger-soft);
  border-color: var(--danger-border);
  margin-bottom: 24px;
}
.warning--strong svg { color: var(--danger); }

/* 获取兑换码引导：可点击的强调文案，点击打开公众号弹层 */
.get-code-hint {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 14px auto 0;
  padding: 8px 12px;
  font-size: 12px;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(0, 117, 222, 0.18);
  border-radius: 999px;
  cursor: pointer;
  text-align: center;
  justify-content: center;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.get-code-hint:hover,
.get-code-hint:focus-visible {
  background: rgba(0, 117, 222, 0.14);
  border-color: rgba(0, 117, 222, 0.32);
  outline: none;
}
.get-code-hint svg { width: 14px; height: 14px; flex-shrink: 0; }
.get-code-hint strong { font-weight: 700; }

/* ---------- Footer ---------- */
.footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px 44px;
  text-align: center;
}
.copyright { margin: 10px 0 0; font-size: 12px; color: var(--text-3); }

/* ============================================================
   响应式断点
   ============================================================ */

/* 手机竖屏（< 480px） */
@media (max-width: 480px) {
  .header-inner, .main, .footer { padding-left: 16px; padding-right: 16px; }
  .card { padding: 24px 18px; }
  .hero-title { font-size: 23px; }
  .products { gap: 7px; }
  .product { padding: 5px 10px; font-size: 12px; }
  .code-input input { font-size: 20px; padding: 13px 6px; }
  .cred-label-text { display: none; }
  .btn-copy { padding: 6px 10px; }
  .popover {
    position: fixed;
    top: 64px;
    left: 12px;
    right: 12px;
    width: auto;
    padding: 18px;
  }
  .popover-img { width: 100%; height: auto; aspect-ratio: 1 / 1; max-width: 300px; margin: 0 auto; }
  .popover-arrow { display: none; }
  /* 空间紧凑：移动端隐藏剩余数量徽标，保留赞赏与领码入口 */
  .remaining { display: none; }
  .mp-hint-full { display: none; }
  .mp-hint-short { display: inline; }
}

/* 平板（481px ~ 768px） */
@media (min-width: 481px) and (max-width: 768px) {
  .main { padding: 40px 28px 56px; }
  .card { padding: 34px 30px; }
  .products { gap: 9px; }
}

/* 桌面端（> 768px） */
@media (min-width: 769px) {
  :root { --maxw: 640px; }
  .main { padding: 48px 32px 64px; }
  .card {
    padding: 40px 44px;
    border-radius: var(--r-lg);
    box-shadow: var(--shadow-3);
  }
  .hero-title { font-size: 32px; }
  .hero-sub { font-size: 15px; }
  .products { gap: 10px; }
  .product { padding: 7px 16px; font-size: 14px; }
  .product-icon { width: 17px; height: 17px; }
  .code-input input { font-size: 28px; padding: 17px 12px; max-width: 200px; }
  .code-dash { font-size: 26px; }
  .btn-primary { padding: 14px 28px; font-size: 16px; }
  .success-title { font-size: 28px; }
  .cred-value { font-size: 15px; }
  .footer { max-width: 640px; }
}

/* 大桌面（> 1024px） */
@media (min-width: 1025px) {
  :root { --maxw: 720px; }
  .main { padding: 56px 40px 72px; }
  .card { padding: 46px 54px; border-radius: var(--r-lg); }
  .hero-title { font-size: 34px; letter-spacing: -0.03em; }
  .products { gap: 12px; }
  .product { padding: 8px 20px; }
  .header-inner { padding: 16px 24px; }
}

/* 降低动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}