:root {
    --primary: #4a90e2;
    --success: #2ecc71;
    --error: #e74c3c;
    --bg: #f5f7fa;
    --text: #2c3e50;
}

* { box-sizing: border-box; font-family: 'Segoe UI', sans-serif; }

body { background-color: var(--bg); margin: 0; display: flex; justify-content: center; }

.app-container {
    width: 100%;
    max-width: 500px;
    background: white;
    min-height: 100vh;
}

header {
    background: var(--primary);
    color: white;
    padding: 15px;
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 10;
}

.progress-bar {
    height: 6px;
    background: rgba(255,255,255,0.3);
    border-radius: 3px;
    margin-top: 10px;
}

#progress { height: 100%; background: white; transition: width 0.4s ease; border-radius: 3px; }

#cityMap { width: 100%; display: block; border-bottom: 2px solid #ddd; }

.exercise { padding: 15px; }

.sentence-card {
    background: #fff;
    border: 1px solid #e1e8ed;
    padding: 12px;
    border-radius: 10px;
    margin-bottom: 12px;
    line-height: 2.2;
}

/* ADJUSTABLE FIELDS */
.input-field {
    border: 2px solid #cbd5e0;
    border-radius: 6px;
    padding: 4px 8px;
    font-size: 1rem;
    min-width: 50px;
    width: 60px; /* Base width */
    transition: all 0.2s ease;
    text-align: center;
}

.input-field:focus { outline: none; border-color: var(--primary); background: #f0f7ff; }
.correct { border-color: var(--success) !important; background: #f0fff4 !important; }
.incorrect { border-color: var(--error) !important; background: #fff5f5 !important; }

.controls { padding: 0 15px 30px; display: flex; gap: 10px; }

button { flex: 1; padding: 15px; border: none; border-radius: 10px; font-weight: bold; cursor: pointer; }
.btn-primary { background: var(--primary); color: white; }
.btn-secondary { background: #edf2f7; color: #4a5568; }

#feedback-msg {
    text-align: center;
    padding: 15px;
    margin: 0 15px 20px;
    border-radius: 8px;
    font-weight: bold;
}

.hidden { display: none; }
.visible { display: block; }