@import url('https://fonts.googleapis.com/css2?family=Helvetica+Neue:wght@300;400;500&display=swap');

:root {
  --bg-color: #2D2D2D;
  --text-main: #E0E0E0;
  --text-dim: #888888;
  
  --key-base: #3b3b3b;
  --key-top: #4a4a4a;
  --key-shadow: #1a1a1a;
  --key-drop-shadow: rgba(0,0,0,0.6);
}

html.light-mode {
  --bg-color: #F8FAFC;
  --text-main: #334155;
  --text-dim: #64748B;
  
  --key-base: #E2E8F0;
  --key-top: #F1F5F9;
  --key-shadow: #CBD5E1;
  --key-drop-shadow: rgba(0,0,0,0.15);
}

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

body {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-color);
  min-height: 100vh;
  overflow: hidden;
  display: flex;
  justify-content: center;
  -webkit-font-smoothing: antialiased;
}

.app {
  width: 100%;
  max-width: 600px;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* 表示・言語切り替え用ボタン群 */
.top-controls {
  position: fixed;
  top: 20px;
  right: 20px;
  display: flex;
  gap: 10px;
  z-index: 100;
}

.control-btn {
  padding: 6px 12px;
  min-width: 44px;
  border-radius: 999px;
  background: rgba(128, 128, 128, 0.15);
  color: var(--text-dim);
  border: none;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: all 0.2s ease;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
}
.control-btn:hover {
  background: rgba(128, 128, 128, 0.3);
  color: var(--text-main);
  transform: translateY(-2px);
}

/* ヘッダー全体 */
.header {
  padding: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 10;
  width: 100%;
}

.back-link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}
.back-link:hover {
  color: var(--text-main);
}

.switch-select {
  padding: 0.6rem 1.2rem;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(0,0,0,0.2);
  font-size: 0.9rem;
  color: var(--text-main);
  outline: none;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  text-align: center;
  font-family: inherit;
  transition: all 0.3s;
}
.switch-select:hover {
  background: rgba(0,0,0,0.4);
}

/* キーボードエリア */
.keyboard-area {
  flex-grow: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer; /* 画面全体でタップ可能 */
  -webkit-tap-highlight-color: transparent;
}

.keycap-wrapper {
  perspective: 1000px;
}

.keycap {
  position: relative;
  width: 160px;
  height: 160px;
  background: var(--key-base);
  border-radius: 18px;
  box-shadow: 
    0 12px 0 var(--key-shadow),  /* 側面 */
    0 25px 30px var(--key-drop-shadow), /* 大きな影 */
    inset 0 2px 2px rgba(255,255,255,0.1);
  transition: transform 0.05s cubic-bezier(0.2, 0.9, 0.4, 1), box-shadow 0.05s cubic-bezier(0.2, 0.9, 0.4, 1);
  display: flex;
  justify-content: center;
  align-items: center;
  user-select: none;
}

/* 押下時のアニメーション状態 */
.keycap.pressed {
  transform: translateY(10px);
  box-shadow: 
    0 2px 0 var(--key-shadow),
    0 10px 15px var(--key-drop-shadow),
    inset 0 2px 2px rgba(255,255,255,0.1);
}

.keycap-top {
  width: 110px;
  height: 110px;
  background: var(--key-top);
  border-radius: 12px;
  /* マットな凹み表現 */
  box-shadow: 
    inset 0 4px 8px rgba(255,255,255,0.05), 
    inset 0 -4px 8px rgba(0,0,0,0.3);
}

/* フッター部 */
.controls {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1.5rem;
}

.hint-msg {
  font-size: 0.85rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-align: center;
  animation: pulse 2s infinite alternate;
}

@keyframes pulse {
  0% { opacity: 0.5; }
  100% { opacity: 1; }
}