/* ===================================
   Training Record - Auth Pages Styles
   Designer監修: Material Design 3準拠
   app_colors.dart / app_theme.dart と完全統一
   =================================== */

/* ===== CSS Variables (Design Tokens) ===== */
:root {
  /* Primary: コーラルピンク */
  --primary: #FF8A80;
  --primary-container: #FFE4E1;
  --on-primary: #FFFFFF;
  --on-primary-container: #5D0012;

  /* Secondary: ライラック */
  --secondary: #E1BEE7;
  --secondary-container: #F3E5F5;
  --on-secondary: #4A148C;

  /* Tertiary: ミントグリーン */
  --tertiary: #A5D6A7;
  --tertiary-container: #E8F5E9;
  --on-tertiary: #1B5E20;

  /* Surface & Background */
  --surface: #FFF8E1;
  --background: #FAFAFA;
  --on-surface: #1C1B1F;
  --on-surface-variant: #49454F;

  /* Outline */
  --outline: #79747E;
  --outline-variant: #CAC4D0;

  /* Semantic */
  --error: #B3261E;
  --error-container: #F9DEDC;
  --on-error: #FFFFFF;
  --success: #4CAF50;
  --success-container: #E8F5E9;
  --warning: #FFC107;

  /* Gradients (オンボーディングイラストと統一) */
  --gradient-primary: linear-gradient(135deg, #FF8A80, #FFAB91, #FFCC80);
  --gradient-secondary: linear-gradient(135deg, #E1BEE7, #CE93D8);
  --gradient-success: linear-gradient(135deg, #A5D6A7, #81C784);
  --gradient-bg: linear-gradient(135deg, rgba(255, 138, 128, 0.15), rgba(255, 204, 128, 0.15));

  /* Typography */
  --font-family: 'Noto Sans JP', 'Noto Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  /* Border Radius (app_theme.dartと統一) */
  --radius-small: 8px;
  --radius-medium: 16px;
  --radius-large: 24px;
  --radius-xlarge: 32px;

  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}

/* ===== Dark Mode ===== */
@media (prefers-color-scheme: dark) {
  :root {
    /* Primary: ソフトコーラル */
    --primary: #FF6B6B;
    --primary-container: #93000A;
    --on-primary: #690005;
    --on-primary-container: #FFDAD6;

    /* Secondary: ラベンダー */
    --secondary: #B39DDB;
    --secondary-container: #4A148C;
    --on-secondary: #381E72;

    /* Tertiary: セージ */
    --tertiary: #81C784;
    --tertiary-container: #1B5E20;
    --on-tertiary: #003314;

    /* Surface & Background */
    --surface: #1E1E1E;
    --background: #121212;
    --on-surface: #E6E1E5;
    --on-surface-variant: #CAC4D0;

    /* Outline */
    --outline: #938F99;
    --outline-variant: #49454F;

    /* Semantic */
    --error: #F2B8B5;
    --error-container: #8C1D18;
    --success: #81C784;
    --success-container: #1B5E20;

    /* Gradients */
    --gradient-bg: linear-gradient(135deg, rgba(255, 107, 107, 0.1), rgba(255, 138, 101, 0.1));
  }
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background: var(--background);
  color: var(--on-surface);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

/* ===== Background Pattern ===== */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-bg);
  pointer-events: none;
  z-index: -1;
}

/* ===== Container ===== */
.auth-container {
  width: 100%;
  max-width: 400px;
  animation: fadeIn var(--transition-slow) ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Card ===== */
.auth-card {
  background: white;
  border-radius: var(--radius-large);
  box-shadow: var(--shadow-lg);
  padding: 32px;
  text-align: center;
}

@media (prefers-color-scheme: dark) {
  .auth-card {
    background: var(--surface);
  }
}

/* ===== Illustration ===== */
.auth-illustration {
  width: 200px;
  height: 200px;
  margin: 0 auto 24px;
}

.auth-illustration svg {
  width: 100%;
  height: 100%;
}

/* ===== Typography ===== */
.auth-title {
  font-size: 24px;
  font-weight: 500;
  color: var(--on-surface);
  margin-bottom: 8px;
}

.auth-subtitle {
  font-size: 14px;
  color: var(--on-surface-variant);
  margin-bottom: 24px;
}

.auth-message {
  font-size: 16px;
  color: var(--on-surface);
  margin-bottom: 24px;
  padding: 16px;
  border-radius: var(--radius-medium);
}

.auth-message.success {
  background: var(--success-container);
  color: var(--on-tertiary);
}

.auth-message.error {
  background: var(--error-container);
  color: var(--on-primary-container);
}

/* ===== Instruction ===== */
.auth-instruction {
  margin-top: 24px;
  padding: 20px;
  background: var(--surface);
  border-radius: var(--radius-medium);
  border: 1px dashed var(--outline-variant);
}

.auth-instruction p {
  font-size: 15px;
  color: var(--on-surface);
  line-height: 1.6;
  margin: 0;
  text-align: center;
}

@media (prefers-color-scheme: dark) {
  .auth-instruction {
    background: var(--background);
  }
}

/* ===== Form Elements ===== */
.form-group {
  margin-bottom: 20px;
  text-align: left;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--on-surface);
  margin-bottom: 8px;
}

.input-wrapper {
  position: relative;
}

.form-input {
  width: 100%;
  padding: 14px 48px 14px 16px;
  font-size: 16px;
  font-family: var(--font-family);
  color: var(--on-surface);
  background: white;
  border: 1.5px solid var(--outline-variant);
  border-radius: var(--radius-medium);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

@media (prefers-color-scheme: dark) {
  .form-input {
    background: var(--background);
    color: var(--on-surface);
  }
}

.form-input:focus {
  border-color: var(--primary);
  border-width: 2px;
  padding: 13.5px 47.5px 13.5px 15.5px;
  box-shadow: 0 0 0 4px rgba(255, 138, 128, 0.15);
}

.form-input.error {
  border-color: var(--error);
}

.form-input.error:focus {
  box-shadow: 0 0 0 4px rgba(179, 38, 30, 0.15);
}

/* Password toggle button */
.password-toggle {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  color: var(--on-surface-variant);
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.password-toggle:hover {
  color: var(--on-surface);
}

.password-toggle svg {
  width: 20px;
  height: 20px;
}

/* Error message */
.form-error {
  font-size: 12px;
  color: var(--error);
  margin-top: 6px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.form-error svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

/* ===== Password Strength Indicator ===== */
.password-strength {
  margin-top: 8px;
}

.strength-bar {
  height: 4px;
  background: var(--outline-variant);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 6px;
}

.strength-fill {
  height: 100%;
  border-radius: 2px;
  transition: width var(--transition-normal), background var(--transition-normal);
}

.strength-fill.weak {
  width: 33.33%;
  background: var(--primary);
}

.strength-fill.medium {
  width: 66.66%;
  background: #FFAB91;
}

.strength-fill.strong {
  width: 100%;
  background: var(--tertiary);
}

.strength-text {
  font-size: 12px;
  color: var(--on-surface-variant);
}

.strength-text.weak {
  color: var(--primary);
}

.strength-text.medium {
  color: #FF8A65;
}

.strength-text.strong {
  color: var(--tertiary);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  font-size: 16px;
  font-weight: 500;
  font-family: var(--font-family);
  border: none;
  border-radius: var(--radius-medium);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
  min-height: 48px;
  min-width: 48px;
}

.btn:active {
  transform: scale(0.98);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* Primary button with gradient */
.btn-primary {
  background: var(--gradient-primary);
  color: var(--on-primary);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
  box-shadow: var(--shadow-md);
}

/* Full width button */
.btn-block {
  width: 100%;
}

/* Text button */
.btn-text {
  background: none;
  color: var(--primary);
  padding: 8px 16px;
}

.btn-text:hover {
  background: rgba(255, 138, 128, 0.08);
}

/* ===== Loading Spinner ===== */
.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* Loading overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.loading-overlay.active {
  opacity: 1;
  visibility: visible;
}

.loading-card {
  background: white;
  padding: 32px 48px;
  border-radius: var(--radius-large);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

@media (prefers-color-scheme: dark) {
  .loading-card {
    background: var(--surface);
  }
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--outline-variant);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text {
  font-size: 14px;
  color: var(--on-surface-variant);
}

/* ===== State Displays ===== */
.state-display {
  display: none;
  flex-direction: column;
  align-items: center;
}

.state-display.active {
  display: flex;
}

/* ===== Footer / Help Link ===== */
.auth-footer {
  margin-top: 24px;
  font-size: 14px;
  color: var(--on-surface-variant);
}

.auth-footer a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

.auth-footer a:hover {
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
  body {
    padding: 12px;
  }

  .auth-card {
    padding: 24px;
    border-radius: var(--radius-medium);
  }

  .auth-illustration {
    width: 160px;
    height: 160px;
  }

  .auth-title {
    font-size: 20px;
  }
}

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus visible for keyboard navigation */
.btn:focus-visible,
.form-input:focus-visible,
.password-toggle:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* High contrast mode */
@media (prefers-contrast: high) {
  .form-input {
    border-width: 2px;
  }

  .btn-primary {
    background: var(--primary);
  }
}