/* --- 基本設定 --- */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    text-align: center;
    padding: 20px;
    box-sizing: border-box;
    position: relative;
    /* ★ 変更：アニメーションを削除しました */
    overflow: hidden;
    
    /* カラーモード：デフォルト */
    background: linear-gradient(120deg, #a1c4fd 0%, #c2e9fb 100%);
    color: #333;
}

/* カラーモード：休憩 */
body.break-bg {
    background: linear-gradient(120deg, #a8e063 0%, #56ab2f 100%);
}

/* --- ★★★ 白黒モード ★★★ */
body.monochrome {
    background: #121212;
    color: #f5f5f5;
}
body.monochrome.break-bg {
    background: #f5f5f5;
    color: #121212;
}

/* --- 角のボタン共通スタイル --- */
.corner-btn {
    position: absolute; display: flex; align-items: center; justify-content: center;
    width: 50px; height: 50px; border-radius: 50%; padding: 0; z-index: 10;
    cursor: pointer; transition: all 0.2s ease;
    
    border: 2px solid #333;
    color: #333;
    background-color: rgba(255, 255, 255, 0.5);
}
.corner-btn:hover { transform: scale(1.05); }

/* 白黒モード時の角ボタン */
body.monochrome .corner-btn {
    border-color: #f5f5f5;
    color: #f5f5f5;
    background-color: rgba(0, 0, 0, 0.2);
}
body.monochrome.break-bg .corner-btn {
    border-color: #121212;
    color: #121212;
    background-color: rgba(255, 255, 255, 0.2);
}

.corner-btn svg { width: 24px; height: 24px; }
.home-button { top: 25px; left: 25px; text-decoration: none; }
.home-button svg { width: 28px; height: 28px; }
#fullscreen-btn { top: 25px; right: 25px; }
#color-mode-btn { bottom: 25px; left: 25px; }

/* ボタンのホバーエフェクト */
.corner-btn:hover { background-color: #333; color: #fff; }
body.monochrome .corner-btn:hover { background-color: #f5f5f5; color: #121212; }
body.monochrome.break-bg .corner-btn:hover { background-color: #121212; color: #f5f5f5; }

/* --- UIコンテナ --- */
#pomodoro-container, #clock-container {
    width: 100%; display: flex; flex-direction: column;
    justify-content: center; align-items: center;
    transition: opacity 0.3s ease-in-out, transform 0.3s ease-in-out;
}

/* --- ポモドーロタイマー --- */
.timer-container { margin-bottom: 2rem; }
#mode { font-size: 2rem; font-weight: 300; color: #555; }
body.monochrome #mode { color: #aaa; }
body.monochrome.break-bg #mode { color: #555; }

#time, #current-time {
    font-size: 10rem; font-weight: bold;
}
.controls { display: flex; gap: 10px; }
.controls button, .stats button, #back-button {
    padding: 10px 20px; font-size: 1rem; cursor: pointer;
    border-radius: 8px; transition: all 0.2s ease;
    
    background-color: transparent;
    border: 2px solid #333;
    color: #333;
}
.controls button:hover, .stats button:hover, #back-button:hover {
    background-color: #333;
    color: white;
}
/* 白黒モード時のボタン */
body.monochrome .controls button, body.monochrome .stats button, body.monochrome #back-button {
    border-color: #f5f5f5; color: #f5f5f5;
}
body.monochrome.break-bg .controls button, body.monochrome.break-bg .stats button, body.monochrome.break-bg #back-button {
    border-color: #121212; color: #121212;
}
body.monochrome .controls button:hover, body.monochrome .stats button:hover, body.monochrome #back-button:hover {
    background-color: #f5f5f5; color: #121212;
}
body.monochrome.break-bg .controls button:hover, body.monochrome.break-bg .stats button:hover, body.monochrome.break-bg #back-button:hover {
    background-color: #121212; color: #f5f5f5;
}

.stats { margin-top: 2rem; font-size: 1.2rem; }
.stats p { margin: 5px 0; }
.stats button { margin-top: 10px; }

/* --- 現在時刻表示 --- */
#clock-container { position: absolute; }
#back-button { margin-top: 2rem; }

/* --- 表示切替アニメーション --- */
.hidden {
    opacity: 0;
    transform: scale(0.95);
    pointer-events: none;
}