/* Level Tree — Duolingo-style winding path */

.level-tree {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 8px 0 40px;
    gap: 0;
}

/* Stage header */
.level-stage-header {
    width: 100%;
    display: flex;
    justify-content: center;
    margin: 20px 0 12px;
}

.level-stage-header:first-child {
    margin-top: 8px;
}

.level-stage-badge {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 4px 16px;
    border-radius: 12px;
}

/* Connector lines between nodes */
.level-connector {
    width: 3px;
    height: 28px;
    background: var(--stage-color, #666);
    opacity: 0.5;
    border-radius: 2px;
}

.level-connector.locked {
    background: rgba(255, 255, 255, 0.1);
    opacity: 0.3;
}

/* Level node */
.level-node {
    display: flex;
    align-items: center;
    gap: 14px;
    width: 85%;
    max-width: 320px;
    padding: 12px 16px;
    border-radius: 16px;
    transition: transform 0.2s, opacity 0.2s;
    cursor: default;
    position: relative;
}

/* Zigzag positioning */
.level-node.left {
    align-self: flex-start;
    margin-left: 8%;
}

.level-node.right {
    align-self: flex-end;
    margin-right: 8%;
    flex-direction: row-reverse;
    text-align: right;
}

/* State: Completed */
.level-node.completed {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.level-node.completed .level-node-circle {
    background: var(--stage-color);
    color: #fff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

/* State: Active (unlocked / in_progress) */
.level-node.unlocked,
.level-node.in_progress {
    background: rgba(255, 255, 255, 0.08);
    border: 2px solid var(--stage-color);
    cursor: pointer;
    box-shadow: 0 0 0 4px color-mix(in srgb, var(--stage-color) 15%, transparent);
}

.level-node.unlocked:active,
.level-node.in_progress:active {
    transform: scale(0.97);
}

.level-node.unlocked .level-node-circle,
.level-node.in_progress .level-node-circle {
    background: var(--stage-color);
    color: #fff;
    animation: levelPulse 2s ease-in-out infinite;
}

/* State: Locked */
.level-node.locked {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    opacity: 0.45;
    pointer-events: none;
}

.level-node.locked .level-node-circle {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-secondary, #999);
    font-size: 16px;
}

/* Circle icon */
.level-node-circle {
    width: 48px;
    height: 48px;
    min-width: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 700;
    transition: background 0.3s;
}

/* Info section */
.level-node-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
    flex: 1;
}

.level-node-name {
    font-size: 14px;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-primary, #fff);
}

.level-node-score {
    font-size: 12px;
    font-weight: 600;
    padding: 1px 8px;
    border-radius: 8px;
    display: inline-block;
    width: fit-content;
}

.level-node-score.score-good {
    background: rgba(76, 175, 80, 0.2);
    color: #4CAF50;
}

.level-node-score.score-mid {
    background: rgba(255, 152, 0, 0.2);
    color: #FF9800;
}

.level-node-score.score-low {
    background: rgba(244, 67, 54, 0.2);
    color: #F44336;
}

.level-node-cta {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--stage-color);
    margin-top: 2px;
}

/* Pulse animation for active nodes */
@keyframes levelPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.2); }
    50% { box-shadow: 0 0 0 8px rgba(255, 255, 255, 0); }
}

/* Shake animation for locked nodes */
@keyframes levelShake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

/* Right-aligned node adjustments */
.level-node.right .level-node-info {
    align-items: flex-end;
}

.level-node.right .level-node-score {
    margin-left: auto;
}

/* === Level replay === */
.level-node.completed {
    cursor: pointer;
    pointer-events: auto;
    opacity: 0.85;
    transition: transform 120ms ease, opacity 120ms ease;
}

.level-node.completed:hover {
    opacity: 1;
    transform: scale(1.03);
}

.level-node.completed .level-node-cta {
    opacity: 0.8;
}