:root {
  --green-900: #1b4332;
  --green-700: #2d6a4f;
  --green-500: #40916c;
  --green-100: #d8f3dc;
  --gold: #f4d35e;
  --gold-hover: #f9e076;
  --bg: #f6faf7;
  --card: #ffffff;
  --text: #1a1a1a;
  --muted: #5c6b63;
  --border: #d4e4da;
  --error: #c1121f;
  --fb: #1877f2;
  --fb-light: #e7f0ff;
  --ig-start: #f58529;
  --ig-end: #dd2a7b;
  --ig-light: #fff0f6;
  --radius: 14px;
  --shadow: 0 8px 30px rgba(27, 67, 50, 0.08);
  --shadow-hover: 0 12px 36px rgba(27, 67, 50, 0.14);
  --ease: 0.2s ease;
}

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

body {
  margin: 0;
  font-family: "Noto Sans TC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

.page {
  max-width: 520px;
  margin: 0 auto;
  padding: 24px 16px 40px;
}

.hero {
  text-align: center;
  padding: 28px 12px 20px;
  transition: transform var(--ease);
}

.hero-badge {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--green-700);
  background: var(--green-100);
  border-radius: 999px;
  transition: background var(--ease), color var(--ease), transform var(--ease), box-shadow var(--ease);
}

.hero h1 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--green-900);
  transition: color var(--ease);
}

.hero-sub {
  margin: 8px 0 0;
  font-size: 1.125rem;
  color: var(--muted);
}

.hero-sub strong {
  color: var(--green-700);
  font-size: 1.35rem;
  transition: color var(--ease);
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 16px;
  border: 1px solid var(--border);
  transition: box-shadow var(--ease), border-color var(--ease), transform var(--ease);
}

.steps h2,
.form-card h2,
.success-card h2 {
  margin: 0 0 12px;
  font-size: 1.05rem;
  color: var(--green-900);
}

.steps-intro {
  margin: 0 0 16px;
  font-size: 0.9rem;
  color: var(--muted);
}

.steps-intro strong {
  color: var(--green-700);
}

.platform-block {
  padding: 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fafcfa;
  transition: border-color var(--ease), background var(--ease), box-shadow var(--ease), transform var(--ease);
}

.platform-block--fb {
  border-color: #c8daf5;
}

.platform-block--ig {
  border-color: #f5c4d8;
}

.platform-name {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--green-900);
}

.platform-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  transition: transform var(--ease), box-shadow var(--ease);
}

.platform-icon--fb {
  background: var(--fb);
  font-family: Georgia, serif;
}

.platform-icon--ig {
  background: linear-gradient(135deg, var(--ig-start), var(--ig-end));
  font-size: 0.7rem;
}

.platform-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.platform-or {
  margin: 14px 0;
  text-align: center;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.btn-action {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 12px;
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  text-decoration: none;
  text-align: center;
  border-radius: 10px;
  border: 2px solid transparent;
  cursor: pointer;
  transition:
    background var(--ease),
    color var(--ease),
    border-color var(--ease),
    transform var(--ease),
    box-shadow var(--ease);
}

.btn-action--like {
  color: var(--green-900);
  background: #fff;
  border-color: var(--border);
}

.platform-block--fb .btn-action--like:hover,
.platform-block--fb .btn-action--like:focus-visible {
  background: var(--fb-light);
  border-color: var(--fb);
  color: var(--fb);
}

.platform-block--ig .btn-action--like:hover,
.platform-block--ig .btn-action--like:focus-visible {
  background: var(--ig-light);
  border-color: var(--ig-end);
  color: var(--ig-end);
}

.btn-action--share {
  color: #fff;
}

.platform-block--fb .btn-action--share {
  background: var(--fb);
}

.platform-block--fb .btn-action--share:hover,
.platform-block--fb .btn-action--share:focus-visible {
  background: #0d65d9;
  box-shadow: 0 4px 14px rgba(24, 119, 242, 0.4);
}

.platform-block--ig .btn-action--share {
  background: linear-gradient(135deg, var(--ig-start), var(--ig-end));
}

.platform-block--ig .btn-action--share:hover,
.platform-block--ig .btn-action--share:focus-visible {
  box-shadow: 0 4px 14px rgba(221, 42, 123, 0.4);
  filter: brightness(1.06);
}

.steps-list {
  margin: 16px 0 0;
  padding-left: 1.25rem;
}

.steps-list li {
  margin-bottom: 6px;
  font-size: 0.9rem;
}

.note {
  margin: 12px 0 0;
  font-size: 0.875rem;
  color: var(--muted);
  font-style: italic;
}

.form-hint {
  margin: -4px 0 16px;
  font-size: 0.875rem;
  color: var(--muted);
}

.field {
  margin-bottom: 20px;
  border: none;
  padding: 0;
  min-width: 0;
}

.field legend,
.field > label {
  display: block;
  font-weight: 500;
  margin-bottom: 8px;
  font-size: 0.95rem;
  transition: color var(--ease);
}

.req {
  color: var(--error);
}

input[type="text"] {
  width: 100%;
  padding: 12px 14px;
  font-size: 1rem;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  transition: border-color var(--ease), box-shadow var(--ease), background var(--ease);
}

input[type="text"]:hover {
  border-color: #b8d4c4;
  background: #fefffe;
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--green-500);
  box-shadow: 0 0 0 3px rgba(64, 145, 108, 0.2);
}

.help {
  margin: 6px 0 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.choice-grid {
  display: grid;
  gap: 10px;
}

.choice-grid--2 {
  grid-template-columns: 1fr 1fr;
}

.choice-grid--referral {
  grid-template-columns: 1fr 1fr;
}

.choice {
  cursor: pointer;
}

.choice input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.choice-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 72px;
  padding: 12px;
  border: 2px solid var(--border);
  border-radius: 12px;
  background: #fff;
  text-align: center;
  transition:
    border-color var(--ease),
    background var(--ease),
    transform var(--ease),
    box-shadow var(--ease);
}

.choice--compact .choice-box {
  min-height: 48px;
  font-size: 0.85rem;
  font-weight: 500;
}

.choice-title {
  font-weight: 600;
  color: var(--green-900);
}

.choice-desc {
  font-size: 0.8rem;
  color: var(--muted);
}

.choice:hover .choice-box {
  border-color: #b8d4c4;
  box-shadow: 0 4px 12px rgba(27, 67, 50, 0.06);
}

.choice input:focus-visible + .choice-box {
  outline: 2px solid var(--green-500);
  outline-offset: 2px;
}

.choice input:checked + .choice-box {
  border-color: var(--green-700);
  background: var(--green-100);
  box-shadow: 0 4px 12px rgba(45, 106, 79, 0.12);
}

.choice:hover input:checked + .choice-box {
  border-color: var(--green-900);
  background: #ccebd4;
}

.choice:active .choice-box {
  transform: scale(0.98);
}

.field-error {
  display: none;
  align-items: flex-start;
  gap: 8px;
  margin: 10px 0 0;
  padding: 10px 12px;
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1.45;
  color: #9b2226;
  background: linear-gradient(135deg, #fff5f5 0%, #fde8ea 100%);
  border: 1px solid #f5c2c7;
  border-radius: 10px;
}

.field-error.is-visible {
  display: flex;
  animation: errorIn 0.25s ease;
}

.field-error[hidden] {
  display: none !important;
}

.field-error::before {
  content: "!";
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 700;
  color: #fff;
  background: var(--error);
  border-radius: 50%;
}

.field.is-invalid input[type="text"] {
  border-color: #e07a83;
  background: #fffbfb;
  box-shadow: 0 0 0 3px rgba(193, 18, 31, 0.1);
}

.field.is-invalid .choice-box {
  border-color: #e07a83;
  background: #fffbfb;
}

.field.is-invalid legend {
  color: #9b2226;
}

.field.shake {
  animation: shake 0.45s ease;
}

@keyframes errorIn {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

.form-error {
  display: none;
  align-items: flex-start;
  gap: 8px;
  margin: 0 0 12px;
  padding: 10px 12px;
  font-size: 0.875rem;
  font-weight: 500;
  color: #9b2226;
  background: linear-gradient(135deg, #fff5f5 0%, #fde8ea 100%);
  border: 1px solid #f5c2c7;
  border-radius: 10px;
}

.form-error.is-visible {
  display: flex;
}

.form-error[hidden] {
  display: none !important;
}

.form-error::before {
  content: "!";
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 700;
  color: #fff;
  background: var(--error);
  border-radius: 50%;
}

.btn-primary {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 20px;
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  color: var(--green-900);
  background: linear-gradient(180deg, var(--gold) 0%, #e9c46a 100%);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(244, 211, 94, 0.45);
  transition:
    transform var(--ease),
    opacity var(--ease),
    box-shadow var(--ease),
    background var(--ease);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(244, 211, 94, 0.55);
  background: linear-gradient(180deg, var(--gold-hover) 0%, #edd080 100%);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.btn-spinner {
  width: 18px;
  height: 18px;
  border: 2px solid rgba(27, 67, 50, 0.25);
  border-top-color: var(--green-900);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.success-card {
  text-align: center;
  padding: 32px 20px;
}

.success-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  font-weight: 700;
  color: #fff;
  background: var(--green-700);
  border-radius: 50%;
  transition: transform var(--ease), background var(--ease), box-shadow var(--ease);
}

.success-card p {
  margin: 0;
  color: var(--muted);
}

.footer {
  text-align: center;
  padding: 8px;
}

.footer p {
  margin: 0;
  font-size: 0.75rem;
  color: var(--muted);
  transition: color var(--ease);
}

.hidden-iframe {
  display: none;
  width: 0;
  height: 0;
  border: 0;
}

/* 桌面／滑鼠裝置：卡片與區塊 hover */
@media (hover: hover) {
  .card:hover {
    box-shadow: var(--shadow-hover);
    border-color: #b8d4c4;
  }

  .hero-badge:hover {
    background: var(--green-500);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(64, 145, 108, 0.3);
  }

  .platform-block--fb:hover {
    border-color: var(--fb);
    background: var(--fb-light);
    box-shadow: 0 6px 20px rgba(24, 119, 242, 0.12);
    transform: translateY(-1px);
  }

  .platform-block--ig:hover {
    border-color: var(--ig-end);
    background: var(--ig-light);
    box-shadow: 0 6px 20px rgba(221, 42, 123, 0.12);
    transform: translateY(-1px);
  }

  .platform-block:hover .platform-icon {
    transform: scale(1.08);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  }

  .btn-action:hover {
    transform: translateY(-2px);
  }

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

  .success-card:hover .success-icon {
    transform: scale(1.06);
    background: var(--green-500);
    box-shadow: 0 6px 18px rgba(45, 106, 79, 0.35);
  }

  .footer p:hover {
    color: var(--green-700);
  }
}

@media (max-width: 380px) {
  .choice-grid--2,
  .choice-grid--referral,
  .platform-actions {
    grid-template-columns: 1fr;
  }
}