/* ==========================================================================
   ぬるま湯ネットワーク (nurumayu-net) - 公式サイト スタイルシート
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS 変数定義 & テーマカラー
   -------------------------------------------------------------------------- */
:root {
  --color-bg: #f6f8fb;
  --color-surface: #ffffff;
  --color-surface-elevated: #ffffff;
  --color-surface-subtle: #edf3f8;
  --color-border: #dbe4ec;
  --color-border-light: #eaeff4;

  --color-primary: #2d6d8c;
  --color-primary-hover: #22536b;
  --color-primary-light: #e6f1f6;
  
  --color-accent: #d86944;
  --color-accent-hover: #bd5532;
  --color-accent-light: #faece6;

  --color-text-main: #1f2d3d;
  --color-text-secondary: #566879;
  --color-text-light: #8294a5;

  /* 試聴プレイヤー専用（音響機材感のあるダークトーン） */
  --player-bg: #1c2530;
  --player-surface: #263342;
  --player-border: #35465a;
  --player-text: #f0f4f8;
  --player-text-muted: #95a5b5;
  --player-accent: #38bdf8;
  --player-accent-glow: rgba(56, 189, 248, 0.35);

  --font-base: "Zen Kaku Gothic New", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "Hiragino Sans", "Meiryo", sans-serif;
  --font-mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 2px 4px rgba(28, 37, 48, 0.04);
  --shadow-md: 0 8px 24px rgba(28, 37, 48, 0.08);
  --shadow-lg: 0 16px 36px rgba(28, 37, 48, 0.12);
  --shadow-player: 0 12px 32px rgba(10, 16, 22, 0.35);

  --transition-fast: 0.18s ease;
  --transition-normal: 0.28s ease;
  --max-width: 1080px;
}

/* --------------------------------------------------------------------------
   リセット & ベーススタイル
   -------------------------------------------------------------------------- */
*, *::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-base);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text-main);
  background-color: var(--color-bg);
  background-image: 
    radial-gradient(at 10% 10%, rgba(45, 109, 140, 0.06) 0px, transparent 50%),
    radial-gradient(at 90% 90%, rgba(216, 105, 68, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-hover);
}

ul, ol {
  list-style: none;
}

button, select, input {
  font-family: inherit;
  font-size: inherit;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --------------------------------------------------------------------------
   セクション共通
   -------------------------------------------------------------------------- */
.section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-subtitle {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text-main);
  letter-spacing: 0.02em;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: -0.6rem;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 3px;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
}

/* --------------------------------------------------------------------------
   ボタンコンポーネント
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  box-shadow: var(--shadow-sm);
}

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

.btn-primary:hover {
  background-color: var(--color-primary-hover);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
  background-color: var(--color-surface-subtle);
  border-color: var(--color-text-light);
  transform: translateY(-2px);
}

.btn-accent {
  background-color: var(--color-accent);
  color: #ffffff;
}

.btn-accent:hover {
  background-color: var(--color-accent-hover);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* --------------------------------------------------------------------------
   ヘッダー & ナビゲーション
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition-normal);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand-link {
  display: inline-block;
  color: inherit;
}

.brand-link:hover {
  color: inherit;
}

.site-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-primary);
  line-height: 1.2;
}

.site-catchphrase {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.03em;
  margin-top: 0.15rem;
}

.site-nav ul {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-nav a {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.site-nav a:hover {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}

/* --------------------------------------------------------------------------
   ヒーローセクション
   -------------------------------------------------------------------------- */
.hero-section {
  padding: 6rem 1.5rem 5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
  background-color: var(--color-primary-light);
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  margin-bottom: 1.5rem;
}

.hero-heading {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.25;
  color: var(--color-text-main);
  margin-bottom: 1.25rem;
}

.hero-subtext {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  line-height: 1.85;
  margin-bottom: 2.2rem;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* --------------------------------------------------------------------------
   About セクション
   -------------------------------------------------------------------------- */
.about-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 3rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.about-intro {
  font-size: 1.2rem;
  line-height: 1.8;
  color: var(--color-text-main);
  margin-bottom: 1.25rem;
}

.about-intro strong {
  color: var(--color-primary);
}

.about-description {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.9;
  margin-bottom: 2.5rem;
}

.about-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.feature-item {
  background-color: var(--color-surface-subtle);
  padding: 1.75rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-light);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--color-text-main);
}

.feature-text {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   Discography セクション
   -------------------------------------------------------------------------- */
.album-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 2.5rem;
  padding: 2.5rem;
  align-items: start;
}

.album-media {
  position: relative;
}

.jacket-container {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: #1a232b;
  box-shadow: var(--shadow-md);
}

.album-jacket {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.jacket-container:hover .album-jacket {
  transform: scale(1.02);
}

.jacket-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}

.album-cat-no {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  background-color: var(--color-primary-light);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  margin-bottom: 0.5rem;
}

.album-title {
  font-size: 1.85rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.35rem;
  color: var(--color-text-main);
}

.album-genre {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 1.25rem;
}

.album-meta dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.6rem 1.2rem;
  font-size: 0.9rem;
  padding: 1.25rem;
  background-color: var(--color-surface-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
}

.album-meta dt {
  font-weight: 700;
  color: var(--color-text-secondary);
}

.album-meta dd {
  color: var(--color-text-main);
}

.price-tag {
  font-weight: 600;
  color: var(--color-primary-hover);
}

.album-description {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.album-actions {
  margin-bottom: 1.75rem;
}

.btn-booth {
  width: 100%;
  font-size: 1rem;
  padding: 1rem;
}

/* --------------------------------------------------------------------------
   試聴プレイヤー (Audio Preview Player)
   -------------------------------------------------------------------------- */
.preview-player {
  background: linear-gradient(145deg, var(--player-bg), #141b24);
  color: var(--player-text);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  border: 1px solid var(--player-border);
  box-shadow: var(--shadow-player);
}

.player-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--player-border);
}

.player-heading-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--player-accent);
  letter-spacing: 0.05em;
}

.track-indicator {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--player-text-muted);
}

.track-selector-wrapper {
  margin-bottom: 1rem;
}

.selector-label {
  display: block;
  font-size: 0.8rem;
  color: var(--player-text-muted);
  margin-bottom: 0.35rem;
}

.track-select {
  width: 100%;
  padding: 0.65rem 0.9rem;
  background-color: var(--player-surface);
  color: var(--player-text);
  border: 1px solid var(--player-border);
  border-radius: var(--radius-sm);
  outline: none;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.track-select:focus {
  border-color: var(--player-accent);
}

.track-select option {
  background-color: var(--player-bg);
  color: var(--player-text);
}

.player-now-playing {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.85rem;
}

.now-playing-label {
  font-size: 0.75rem;
  color: var(--player-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.now-playing-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: #ffffff;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* プログレスバー（シークバー） */
.player-timeline {
  margin-bottom: 1.25rem;
}

.seek-bar {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--player-surface);
  border-radius: var(--radius-full);
  outline: none;
  cursor: pointer;
  position: relative;
  transition: background var(--transition-fast);
}

.seek-bar::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--player-accent);
  box-shadow: 0 0 8px var(--player-accent-glow);
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.seek-bar::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}

.seek-bar::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border: none;
  border-radius: 50%;
  background: var(--player-accent);
  box-shadow: 0 0 8px var(--player-accent-glow);
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.time-display {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--player-text-muted);
  margin-top: 0.35rem;
}

.time-separator {
  margin: 0 0.25rem;
}

/* プレイヤーボタン群 */
.player-controls {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
}

.player-btn {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid var(--player-border);
  background-color: var(--player-surface);
  color: var(--player-text);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.player-btn:hover {
  background-color: #314254;
  border-color: #475d74;
  color: #ffffff;
  transform: translateY(-1px);
}

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

.play-btn {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: #ffffff;
}

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

.play-btn.is-active {
  background-color: var(--player-accent);
  border-color: var(--player-accent);
  color: #0b131c;
  box-shadow: 0 0 12px var(--player-accent-glow);
}

.btn-symbol {
  font-size: 0.85rem;
}

.player-status {
  font-size: 0.78rem;
  color: var(--player-accent);
  text-align: center;
  margin-top: 0.75rem;
  min-height: 1.2em;
  transition: color var(--transition-fast);
}

.player-status.is-error {
  color: #f87171;
}

/* --------------------------------------------------------------------------
   News / Event セクション
   -------------------------------------------------------------------------- */
.news-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  max-width: 860px;
  margin: 0 auto;
}

.news-item {
  background-color: var(--color-surface);
  padding: 1.75rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.news-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.news-date {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-right: 0.75rem;
}

.news-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
}

.tag-event {
  background-color: var(--color-accent-light);
  color: var(--color-accent);
}

.tag-info {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}

.news-item-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-main);
  margin: 0.75rem 0 0.5rem;
}

.news-text {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* --------------------------------------------------------------------------
   Contact / Links セクション
   -------------------------------------------------------------------------- */
.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.link-card {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  background-color: var(--color-surface);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  color: inherit;
}

a.link-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  color: inherit;
}

.link-icon {
  font-size: 2rem;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background-color: var(--color-surface-subtle);
  flex-shrink: 0;
}

.link-info {
  flex: 1;
}

.link-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text-main);
  margin-bottom: 0.25rem;
}

.link-desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.link-arrow {
  font-size: 1.25rem;
  color: var(--color-text-light);
  transition: transform var(--transition-fast), color var(--transition-fast);
}

a.link-card:hover .link-arrow {
  color: var(--color-primary);
  transform: translateX(4px);
}

.link-contact {
  grid-column: 1 / -1;
  background-color: var(--color-surface-subtle);
  border-color: var(--color-border-light);
}

/* --------------------------------------------------------------------------
   フッター
   -------------------------------------------------------------------------- */
.site-footer {
  margin-top: auto;
  background-color: #19222c;
  color: #c4d1dc;
  border-top: 1px solid #283646;
  padding: 3.5rem 1.5rem 2.5rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

.footer-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.35rem;
}

.footer-copy-text {
  font-size: 0.85rem;
  color: #879cb0;
  margin-bottom: 1.5rem;
}

.footer-nav {
  margin-bottom: 2rem;
}

.footer-nav a {
  font-size: 0.85rem;
  color: #a4b6c7;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
}

.footer-nav a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.08);
}

.copyright {
  font-size: 0.8rem;
  color: #6e8294;
  letter-spacing: 0.03em;
}

/* --------------------------------------------------------------------------
   レスポンシブ対応 (Media Queries)
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
  .album-card {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 2rem;
  }

  .album-media {
    max-width: 440px;
    margin: 0 auto;
    width: 100%;
  }
}

@media (max-width: 768px) {
  .site-header .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.85rem 1.25rem;
  }

  .site-nav ul {
    gap: 0.75rem;
    flex-wrap: wrap;
  }

  .site-nav a {
    font-size: 0.85rem;
    padding: 0.3rem 0.5rem;
  }

  .hero-section {
    padding: 4rem 1.25rem 3.5rem;
  }

  .hero-heading {
    font-size: 2.1rem;
  }

  .hero-subtext {
    font-size: 1rem;
  }

  .section {
    padding: 3.5rem 0;
  }

  .about-card {
    padding: 1.75rem;
  }

  .album-card {
    padding: 1.5rem;
  }

  .album-title {
    font-size: 1.5rem;
  }

  .album-meta dl {
    grid-template-columns: 1fr;
    gap: 0.35rem;
  }

  .album-meta dt {
    font-size: 0.8rem;
    color: var(--color-primary);
  }

  .player-controls {
    flex-direction: column;
  }

  .links-grid {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   テスト公開用 パスワードゲート (Gate Overlay & Modal)
   ========================================================================== */
body.gate-locked {
  overflow: hidden;
}

.gate-overlay {
  position: fixed;
  inset: 0;
  z-index: 999999;
  background-color: rgba(246, 248, 251, 0.94);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  transition: opacity 0.35s ease, visibility 0.35s ease;
}

.gate-overlay.gate-passed {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.gate-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  max-width: 440px;
  width: 100%;
  padding: 2.5rem 2rem;
  text-align: center;
  box-sizing: border-box;
  animation: gateCardPop 0.3s ease-out;
}

@keyframes gateCardPop {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.gate-icon {
  font-size: 2.2rem;
  line-height: 1;
  margin-bottom: 0.75rem;
}

.gate-badge {
  display: inline-block;
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.gate-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-main);
  margin-bottom: 0.5rem;
}

.gate-description {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.gate-form {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.gate-input-group {
  width: 100%;
}

.gate-input {
  width: 100%;
  padding: 0.85rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--color-text-main);
  background-color: var(--color-surface-subtle);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  box-sizing: border-box;
  text-align: center;
}

.gate-input:focus {
  border-color: var(--color-primary);
  background-color: var(--color-surface);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.gate-error {
  font-size: 0.82rem;
  color: #d93025;
  font-weight: 500;
  background-color: #fde8e8;
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  animation: fadeIn 0.2s ease;
}

.gate-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 700;
  font-family: inherit;
  color: #ffffff;
  background-color: var(--color-primary);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.gate-btn:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-1px);
}

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

.gate-hint {
  margin-top: 1.25rem;
  font-size: 0.75rem;
  color: var(--color-text-light);
}

/* 誤入力時のシェイクアニメーション */
.gate-shake {
  animation: gateShakeKeyframes 0.4s ease;
  border-color: #d93025 !important;
}

@keyframes gateShakeKeyframes {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}