:root {
    --bg-idle: #1e3a8a;    /* Blue */
    --bg-memo: #c2410c;    /* Orange */
    --bg-exec: #15803d;    /* Green */
    --bg-dark: #1f2937;    /* Dark (Stats/Results) */
    --text: #f3f4f6;
}

body { margin: 0; background: var(--bg-idle); color: var(--text); font-family: sans-serif; height: 100vh; overflow: hidden; }

/* DYNAMIC BACKGROUNDS */
#app { height: 100%; display: flex; flex-direction: column; align-items: center; justify-content: center; transition: background 0.3s; }
.mode-idle { background-color: var(--bg-idle); }
.mode-memo { background-color: var(--bg-memo); }
.mode-exec { background-color: var(--bg-exec); }
.mode-result, .mode-stats, .mode-study { background-color: var(--bg-dark); }

/* HUD */
.hud { position: absolute; top: 0; width: 100%; padding: 15px 20px; display: flex; justify-content: space-between; box-sizing: border-box; background: rgba(0,0,0,0.3); }
.hud-right { display: flex; gap: 10px; align-items: center; }
.hud-btn { background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3); color: white; padding: 5px 12px; cursor: pointer; border-radius: 4px; }
.hud-btn:hover { background: rgba(255,255,255,0.3); }

/* SCREENS */
.screen { display: none; width: 100%; max-width: 600px; flex-direction: column; align-items: center; text-align: center; }
.screen.active { display: flex; animation: fadeUp 0.2s; }
@keyframes fadeUp { from { opacity:0; transform:translateY(10px); } to { opacity:1; transform:translateY(0); } }

/* IDLE */
.settings { display: flex; gap: 15px; background: rgba(0,0,0,0.2); padding: 15px; border-radius: 8px; margin-top: 10px; }

/* MEMO */
.card-display { background: rgba(0,0,0,0.3); padding: 20px; border-radius: 12px; margin-bottom: 15px; }
#memo-img { max-height: 40vh; max-width: 100%; border-radius: 4px; }
#memo-word { font-size: 2rem; font-weight: bold; margin-top: 10px; }
.progress-bar { width: 100%; height: 6px; background: rgba(255,255,255,0.2); border-radius: 3px; }
#memo-progress { height: 100%; background: white; transition: width 0.2s; }

/* EXEC */
#user-input { background: rgba(0,0,0,0.4); border: 2px solid rgba(255,255,255,0.5); color: white; font-size: 3rem; width: 160px; text-align: center; border-radius: 8px; text-transform: uppercase; }
#input-history { display: flex; gap: 5px; flex-wrap: wrap; justify-content: center; margin-bottom: 20px; min-height: 35px; }
.chip { background: rgba(255,255,255,0.2); padding: 5px 10px; border-radius: 4px; font-family: monospace; }

/* STATS (Table View) */
.overlay { background: rgba(0,0,0,0.9); padding: 30px; border-radius: 10px; height: auto; max-height: 90vh; }
.overlay-header { width: 100%; display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.close-btn { background: none; border: none; font-size: 2rem; color: #aaa; cursor: pointer; }

.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; width: 100%; margin-bottom: 20px; }
.stat-box { background: rgba(255,255,255,0.1); padding: 10px; border-radius: 5px; display: flex; flex-direction: column; }
.stat-box span { font-size: 0.8rem; opacity: 0.7; }
.stat-box b { font-size: 1.2rem; }

.table-wrap { width: 100%; max-height: 40vh; overflow-y: auto; background: rgba(0,0,0,0.2); border-radius: 5px; }
.stats-table { width: 100%; border-collapse: collapse; text-align: left; }
.stats-table th { background: rgba(255,255,255,0.1); padding: 10px; position: sticky; top: 0; }
.stats-table td { border-bottom: 1px solid rgba(255,255,255,0.05); padding: 8px; font-size: 0.9rem; }

/* STUDY */
.study-card { background: rgba(255,255,255,0.1); padding: 20px; border-radius: 15px; margin: 20px 0; width: 80%; display: flex; flex-direction: column; align-items: center; }
#study-img { max-height: 250px; max-width: 100%; border-radius: 5px; }
.study-nav { display: flex; gap: 20px; }

/* RESULTS */
#result-list { max-height: 40vh; overflow-y: auto; width: 100%; }
.res-row { display: flex; justify-content: space-between; padding: 8px; background: rgba(255,255,255,0.1); margin-bottom: 5px; border-radius: 4px; }
.res-correct { border-left: 4px solid #4ade80; }
.res-wrong { border-left: 4px solid #ef4444; background: rgba(239, 68, 68, 0.2); }

/* --- Add to your CSS --- */

.finish-btn {
    background: #10b981; /* Green */
    color: white;
    border: none;
    font-size: 1.5rem;
    padding: 15px 40px;
    border-radius: 8px;
    margin-top: 20px;
    cursor: pointer;
    font-weight: bold;
    box-shadow: 0 4px 0 #059669; /* 3D effect */
    transition: transform 0.1s;
}

.finish-btn:active {
    transform: translateY(4px);
    box-shadow: none;
}

.finish-btn:hover {
    background: #34d399;
}

.result-summary {
    display: flex;
    gap: 15px;
    margin-bottom: 10px;
}

.res-box {
    background: rgba(255,255,255,0.1);
    padding: 10px;
    border-radius: 5px;
    text-align: center;
    min-width: 80px;
}
.res-box span { display: block; font-size: 0.8rem; opacity: 0.7; }
.res-box b { font-size: 1.2rem; }

/* Settings UI */
.settings-box {
    background: rgba(0,0,0,0.3);
    padding: 20px;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 300px;
    margin-top: 20px;
}

.setting-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255,255,255,0.05);
    padding: 10px;
    border-radius: 5px;
}

.chk-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1.1rem;
}

.chk-label input[type="checkbox"] {
    transform: scale(1.3);
}

.num-input {
    background: rgba(0,0,0,0.5);
    border: 1px solid #555;
    color: white;
    width: 60px;
    padding: 5px;
    border-radius: 5px;
    text-align: center;
    font-size: 1rem;
}