function updateGameLogic() {
    // 1. Input Logging (Ducken)
    if (isCrouching) {
        inputLog.push({ t: currentTick - lastSentTick, act: "DUCK" });
    }

    // 2. Geschwindigkeit (Basiert auf ZEIT/Ticks, nicht Score!)
    let currentSpeed = 5 + (currentTick / 3000.0) * 0.5;
    if (currentSpeed > 12.0) currentSpeed = 12.0;

    // 3. Spieler Physik & Größe
    const originalHeight = 50;
    const crouchHeight = 25;

    player.h = isCrouching ? crouchHeight : originalHeight;
    let drawY = isCrouching ? player.y + (originalHeight - crouchHeight) : player.y;

    player.vy += GRAVITY;
    if (isCrouching && !player.grounded) player.vy += 2.0; // Fast Fall
    player.y += player.vy;

    if (player.y + originalHeight >= GROUND_Y) {
        player.y = GROUND_Y - originalHeight;
        player.vy = 0;
        player.grounded = true;
    } else {
        player.grounded = false;
    }

    // 4. Hindernisse Bewegen & Kollision
    let nextObstacles = [];

    for (let obs of obstacles) {
        obs.x -= currentSpeed;

        // Aufräumen, wenn links raus
        if (obs.x + obs.def.width < -50.0) continue;

        // --- PASSED CHECK (Wichtig!) ---
        // Wenn das Hindernis den Spieler schon passiert hat, ignorieren wir Kollisionen.
        // Das verhindert "Geister-Treffer" von hinten durch CCD.
        const paddingX = 10;
        const realRightEdge = obs.x + obs.def.width - paddingX;

        // Spieler ist bei 50. Wir geben 5px Puffer.
        if (realRightEdge < 55) {
            nextObstacles.push(obs); // Behalten, aber keine Kollisionsprüfung mehr
            continue;
        }
        // -------------------------------

        // Kollisionsprüfung
        const playerHitbox = { x: player.x, y: drawY, w: player.w, h: player.h };

        if (checkCollision(playerHitbox, obs)) {
            // A. COIN
            if (obs.def.type === "coin") {
                score += 2000;
                continue; // Entfernen
            }
            // B. POWERUP
            else if (obs.def.type === "powerup") {
                if (obs.def.id === "p_god") godModeLives = 3;
                if (obs.def.id === "p_bat") hasBat = true;
                if (obs.def.id === "p_boot") bootTicks = 600;
                lastPowerupTick = currentTick; // Für Sync merken
                continue; // Entfernen
            }
            // C. GEGNER
            else {
                if (hasBat && obs.def.type === "teacher") {
                    hasBat = false;
                    continue; // Zerstört
                }
                if (godModeLives > 0) {
                    godModeLives--;
                    continue; // Geschützt
                }

                player.color = "darkred";
                if (!isGameOver) {
                    sendChunk();
                    gameOver("Kollision");
                }
            }
        }

        nextObstacles.push(obs);
    }
    obstacles = nextObstacles;

    // 5. Spawning (Zeitbasiert & Synchron)

    // Fallback für Init
    if (typeof nextSpawnTick === 'undefined' || nextSpawnTick === 0) {
        nextSpawnTick = currentTick + 50;
    }

    if (currentTick >= nextSpawnTick && gameConfig) {
        // A. Nächsten Termin berechnen
        const gapPixel = Math.floor(400 + rng.nextRange(0, 500));
        const ticksToWait = Math.floor(gapPixel / currentSpeed);
        nextSpawnTick = currentTick + ticksToWait;

        // B. Position setzen (Fix rechts außen)
        let spawnX = GAME_WIDTH + 50;

        // C. Objekt auswählen
        const isBossPhase = (currentTick % 1500) > 1200;
        let possibleObs = [];

        gameConfig.obstacles.forEach(def => {
            if (isBossPhase) {
                if (def.id === "principal" || def.id === "trashcan") possibleObs.push(def);
            } else {
                if (def.id === "principal") return;
                // Eraser erst ab Tick 3000
                if (def.id === "eraser" && currentTick < 3000) return;
                possibleObs.push(def);
            }
        });

        let def = rng.pick(possibleObs);

        // RNG Sync: Speech
        let speech = null;
        if (def && def.canTalk) {
            if (rng.nextFloat() > 0.7) speech = rng.pick(def.speechLines);
        }

        // RNG Sync: Powerup Rarity
        if (def && def.type === "powerup") {
            if (rng.nextFloat() > 0.1) def = null;
        }

        if (def) {
            const yOffset = def.yOffset || 0;
            obstacles.push({
                x: spawnX,
                y: GROUND_Y - def.height - yOffset,
                def: def,
                speech: speech
            });
        }
    }
}

function checkCollision(p, obs) {
    const paddingX = 10;
    const paddingY_Top = (obs.def.type === "teacher") ? 25 : 10;
    const paddingY_Bottom = 5;

    // Speed-basierte Hitbox-Erweiterung (CCD)
    // Wir schätzen den Speed hier, damit er ungefähr dem Server entspricht
    let currentSpeed = 5 + (currentTick / 3000.0) * 0.5;
    if (currentSpeed > 12.0) currentSpeed = 12.0;

    const pLeft = p.x + paddingX;
    const pRight = p.x + p.w - paddingX;
    const pTop = p.y + paddingY_Top;
    const pBottom = p.y + p.h - paddingY_Bottom;

    const oLeft = obs.x + paddingX;
    // Wir erweitern die Hitbox nach rechts um die Geschwindigkeit,
    // um schnelle Durchschüsse zu verhindern.
    const oRight = obs.x + obs.def.width - paddingX + currentSpeed;

    const oTop = obs.y + paddingY_Top;
    const oBottom = obs.y + obs.def.height - paddingY_Bottom;

    return (pRight > oLeft && pLeft < oRight && pBottom > oTop && pTop < oBottom);
}