/* ==========================================================================
   太平新光分校 LIFF 家長綁定頁 · 樣式
   Palette: 教育溫暖紅 + 象牙白 + 深炭灰
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;600;700&family=Inter:wght@400;500;600;700&display=swap');

:root {
  /* 文字 / Type */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.5vw, 1.25rem);
  --text-xl: clamp(1.375rem, 1.2rem + 0.75vw, 1.625rem);

  /* 間距 / Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;

  /* 顏色 / Colors — 教育紅 + 溫暖中性 */
  --color-bg: #fbf7f3;
  --color-surface: #ffffff;
  --color-surface-2: #faf5ef;
  --color-border: #e7dcd0;
  --color-border-strong: #d4c3b1;

  --color-text: #2a1f17;
  --color-text-muted: #6f5e4e;
  --color-text-faint: #a89785;
  --color-text-inverse: #ffffff;

  --color-primary: #c9302c;          /* 弋果紅 */
  --color-primary-hover: #a52520;
  --color-primary-active: #7d1b17;
  --color-primary-soft: #fbe9e7;

  --color-success: #437a22;
  --color-success-soft: #e5f0db;
  --color-error: #a52520;

  /* 圓角 / Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;

  /* 陰影 */
  --shadow-sm: 0 1px 2px rgba(42, 31, 23, 0.06);
  --shadow-md: 0 4px 12px rgba(42, 31, 23, 0.08);
  --shadow-lg: 0 12px 32px rgba(42, 31, 23, 0.12);

  /* 過渡 */
  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* 字型 */
  --font-body: 'Noto Sans TC', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* ==========================================================================
   Base Reset
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  background-image:
    radial-gradient(at 0% 0%, rgba(201, 48, 44, 0.04) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(201, 48, 44, 0.03) 0px, transparent 50%);
}

img, svg { display: block; max-width: 100%; }

button, input, textarea, select {
  font: inherit;
  color: inherit;
}

button { cursor: pointer; background: none; border: none; }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.hidden { display: none !important; }

/* ==========================================================================
   Layout
   ========================================================================== */

.container {
  max-width: 560px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-4) var(--space-12);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.header {
  padding: var(--space-2) 0;
}

.logo-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo {
  color: var(--color-primary);
  flex-shrink: 0;
}

.brand {
  flex: 1;
  min-width: 0;
}

.brand-zh {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.brand-en {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-top: 2px;
}

.lang-toggle {
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  background: var(--color-surface);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  transition: all var(--transition);
  min-width: 52px;
}

.lang-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

fieldset.card {
  border: 1px solid var(--color-border);
}

.card-title {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  width: 100%;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-size: var(--text-xs);
  font-weight: 700;
  flex-shrink: 0;
}

/* ==========================================================================
   Info Card
   ========================================================================== */

.info-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  background: var(--color-primary-soft);
  border-color: rgba(201, 48, 44, 0.15);
}

.info-icon {
  color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 2px;
}

.info-text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Loading / Error
   ========================================================================== */

.loading-card, .error-card, .success-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--space-8) var(--space-5);
  gap: var(--space-3);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

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

.error-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary-soft);
  color: var(--color-error);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
  font-weight: 700;
}

.error-title, .success-title {
  font-size: var(--text-lg);
  font-weight: 700;
}

.error-msg, .success-msg {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  max-width: 36ch;
  line-height: 1.7;
}

/* ==========================================================================
   Form Fields
   ========================================================================== */

.form {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.field-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
}

input[type="text"],
textarea {
  width: 100%;
  padding: var(--space-3);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  font-size: var(--text-base);
  transition: border-color var(--transition);
}

input[type="text"]:focus,
textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

textarea {
  resize: vertical;
  min-height: 80px;
  font-family: inherit;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.submit-row {
  padding: var(--space-2) 0 0;
}

.btn-primary {
  display: block;
  width: 100%;
  padding: var(--space-4);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: 700;
  box-shadow: var(--shadow-md);
  transition: all var(--transition);
  text-align: center;
  text-decoration: none;
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

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

.btn-primary:disabled {
  background: var(--color-text-faint);
  cursor: not-allowed;
  box-shadow: none;
}

.btn-link {
  display: block;
  text-decoration: none;
}

.btn-secondary {
  padding: var(--space-3) var(--space-5);
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  transition: all var(--transition);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ==========================================================================
   Success
   ========================================================================== */

.success-card {
  padding: var(--space-10) var(--space-5);
  gap: var(--space-4);
}

.success-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--color-success-soft);
  color: var(--color-success);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  text-align: center;
  padding: var(--space-4) 0;
}

.footer-text {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

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